Measuring The Relative Velocity Of Light [Archive]

grounded

Jun13-04, 03:46 PM

Anyone attempting to argue the Special Theory of Relativity needs to understand the basics of how light travels, and how we perceive it.

Einstein wrote that the speed of light does not depend on the speed of the object emitting the light. To prove this, Einstein referred to De Sitter’s observation of the binary stars, which are two stars that are orbiting each other. De Sitter concluded that if the speed of light were dependant on the speed of the star, then the light emitted from the star as it is traveling towards us would eventually catch up to the light that was emitted from the same star when it was traveling away from us.

That logic is incorrect since relative to the binary stars, they are not moving and we are orbiting the binary stars. By viewing the stars as motionless, it becomes clear that while we orbit the binary stars, we are running into the light of one star as we are running away from the light from the other star. Relative to the binary stars, their light is not approaching us at different speeds; we are approaching the light at different speeds. This proves that the speed of light can be based off the speed of the star without disturbing our perceptual view of the orbits.

Maxwell stated that all types of light would have a frequency that is inversely proportionate to its wavelength. Einstein believed that an increase in frequency caused by traveling towards the light source would cause an inversely proportionate change in the wavelength. What Maxwell meant was that since all types of light travel from the source at the same speed, than while at rest relative to the source, any light with a high frequency will have a short wavelength, and any light with a low frequency will have a long wavelength since multiplying them together must equal the speed of light. He did not mean that a perceptual change in frequency caused by the observer’s speed would change the wavelength.

The wavelength of light is not a relative measurement; it is the distance that the light has to travel away from the source in order to complete one wave. That distance is not determined by the observer’s speed, it is the same for all observers traveling at any speed or direction. The frequency of light is a relative measurement; it is the number of wavelengths the observer passes in one second. This number is determined by the speed of the observation and will be different between observers traveling at different speeds relative to the source. The wavelength of light is unaffected by the observers speed, any measured change in wavelength is an error that is caused by not including the distance the observer has traveled relative to the source. When calculating the wavelength, the distance that the light travels from the source in one second must be added to the distance the observer has traveled relative to the source in one second, and then divided by the measured frequency. If the distance the observer has traveled is not included, then the relative speed will never change since the total distance traveled would only include the distance the light has traveled.

In order to accurately measure the relative speed between two objects, the distance traveled by both objects in the same amount of time must be included. Interferometers and oscilloscopes only account for the distance that the light has traveled, both need to be adjusted to include the distance traveled by the observer relative to the source. An observer using an interferometer moves a mirror a specific amount of distance while counting the number of changes in the pattern of interference fringes. When used to measure wavelengths while in motion relative to the light source, the scale used to measure the distance that the mirror has moved must be adjusted to include the distance the observer has traveled relative to the source. If the observer is traveling towards the source, the same amount of movement of the mirror will represent a larger distance since it now includes the distance the observer has traveled. If the observer’s distance is not included, any increase in frequency caused by the observer’s speed will appear to decrease the wavelength causing the speed to remain unchanged.

Traveling towards the source will increase the number of waves displayed on the screen of an oscilloscope. Displaying more waves in the same amount of space means the length of each wave displayed on the screen will be reduced. This does not mean that traveling towards the source will reduce the actual length of the waves. The oscilloscope shows the waves closer together because the total distance that the screen represents has been increased to include the distance the observer has traveled relative to the source. Traveling towards the source causes the oscilloscope to use a smaller amount of the screen to represent the same amount of distance. If the distance is not included, any increase in frequency caused by the observer’s speed will appear to decrease the wavelength causing the speed to remain unchanged. While at rest relative to the source, a one second screen of an oscilloscope will represent 186,000 miles. If the oscilloscope is traveling 1,000 miles per second towards the source, then the screen of the oscilloscope must represent 187,000 miles.

Traveling towards the light does not change the distance that the light has to travel to complete one wave, just as traveling towards an oncoming train does not reduce the length of the boxcars. Traveling towards the train will increase the number of boxcars that are passed and it will increase the relative speed between the observer and the train, but it will not change the length of the boxcars. If the observer plotted the number of boxcars that passed in one minute on a four-inch line, and then did the same thing after increasing speed towards the train, the second experiment would have more marks on the four-inch line and they would be closer together. This does not mean the length of the boxcars have gotten shorter, it means that the four-inch line represents a greater distance while traveling towards the source than it does when not moving relative to the source.

The increase in measured frequency caused by the observer’s speed is equal to the distance the observer has traveled (in one-second) towards the source, divided by the known wavelength. When calculating the wavelength using the measured frequency, it must be divided into the sum of “the distance light has traveled away from the source in one second” plus “the distance the observer has traveled towards the source in one second”. When measuring the wavelength, the scale of the tool used to measure the length must account for the distance the observer has traveled relative to the source. While in motion relative to the source, the wavelength or frequency will always be divided into a number that is greater than or less than 186,000 miles, but never equal to 186,000 miles. The frequency multiplied by the wavelength must equal the sum of “the distance that the observer has traveled relative to the source in one second” plus “the distance the light has traveled relative to the source in one second”.

The speed of light is not constant to all observers, and it is not the universal speed limit. Traveling at relativistic speeds will not alter time, lengths, or mass. The Doppler effect is not a stretching or compressing of the wavelengths; it is an increase or decrease in frequency and relative speed. The only way the speed of light can be measured constant between observers traveling at different speeds is to measure a change in the length of the wave. The only way to measure a change in wavelength caused by the observer’s speed is by not including the distance the observer has traveled relative to the source. If the distance the observer has traveled is not included when measuring the speed of the train, then the speed of the train will never change. If the distance the observer has traveled is not included when measuring the speed of the light, then the speed of the light will never change. The Special Theory of Relativity is interesting, but incorrect.

In my opinion, Einstein created the Special Theory of Relativity because he misunderstood the following facts. Frequency and wavelength are only inversely proportionate when measured at rest relative to the source. When measuring the relative speed of light, the distance the observer has traveled relative to the source must be included with the distance that the light has traveled away from the source in the same amount of time. Light travels at about 186,000 miles per second relative to the source. Relative to the orbiting binary stars, we are circling them and are running into the light at different speeds (actually different distances), which explains why we don’t see multiple images of the same star. The wavelength, or the distance light travels away from the source in order to complete one cycle, is not a relative measurement and it cannot be altered by changing speed or direction. Traveling past a wavelength at a faster rate does not mean the light has traveled a shorter distance from the source to complete one cycle. Changing speed relative to the source can only change the number of wavelengths passed and the relative speed of light, not the distance the light has traveled relative to the source. It is not the speed of light that remains constant it’s the wavelength.

Tom Mattson

Jun13-04, 04:58 PM

Anyone attempting to argue the Special Theory of Relativity needs to understand the basics of how light travels, and how we perceive it.

Anyone attempting to argue the Special Theory of Relativity does understand those things, because they are required to study classical electrodynamics in the process.

Einstein wrote that the speed of light does not depend on the speed of the object emitting the light. To prove this, Einstein referred to De Sitter’s observation of the binary stars, which are two stars that are orbiting each other.

That's not all. Einstein opened his case by referring to the observation that, if Galileo's relativity were correct, then the electrodynamics of moving bodies should result in "asymmetries which do not appear to be inherent in the phenomena". That is, Galileo and Maxwell could not both be right.

De Sitter concluded that if the speed of light were dependant on the speed of the star, then the light emitted from the star as it is traveling towards us would eventually catch up to the light that was emitted from the same star when it was traveling away from us.

With you so far.

That logic is incorrect since relative to the binary stars, they are not moving and we are orbiting the binary stars.

No, the logic is just fine. The binary stars are orbiting each other, and it is this relative motion that DeSitter had in mind. You can't simply transform that relative motion away with a change of reference frames, because the motion is accelerated.

By viewing the stars as motionless, it becomes clear that while we orbit the binary stars, we are running into the light of one star as we are running away from the light from the other star. Relative to the binary stars, their light is not approaching us at different speeds; we are approaching the light at different speeds. This proves that the speed of light can be based off the speed of the star without disturbing our perceptual view of the orbits.

No, it doesn't, because you can't fix both stars simultaneously.

Maxwell stated that all types of light would have a frequency that is inversely proportionate to its wavelength. Einstein believed that an increase in frequency caused by traveling towards the light source would cause an inversely proportionate change in the wavelength.

He didn't just "believe" it, it is a consequence of his postulates, which by the way are required to explain the apparent paradoxes in Maxwell's EM theory. One such paradox is that, if Galilean relativity were correct, EM waves would not even appear as EM waves in any frame moving relative to the source.

What Maxwell meant was that since all types of light travel from the source at the same speed, than while at rest relative to the source, any light with a high frequency will have a short wavelength, and any light with a low frequency will have a long wavelength since multiplying them together must equal the speed of light. He did not mean that a perceptual change in frequency caused by the observer’s speed would change the wavelength.

Everyone knows that Einstein's view was an extrapolation of Maxwell's.

The wavelength of light is not a relative measurement; it is the distance that the light has to travel away from the source in order to complete one wave. That distance is not determined by the observer’s speed, it is the same for all observers traveling at any speed or direction.

That is only true if you assume Galilean relativity in the first place. Since that model is now long defunct, there is no reason to assume it. SR has successfully overthrown it, on both theoretical and experimental grounds.

The next 6 paragraphs are based on the same faulty assumption, so I'm going to skip them.

In my opinion, Einstein created the Special Theory of Relativity because he misunderstood the following facts.

In my opinion, you reject relativity because you either misunderstand or are simply unaware of the following facts:

1. The speed of light has actually been measured to be independent of the speed of the source in pion decay experiments.
2. Time dilation has actually been measured in muon decay experiments.
3. Rejecting SR necessarily means rejecting Maxwell's electrodynamics, because Maxwell is only frame-independent under SR.
4. Injecting SR into quantum theory makes it much more accurate, not less so. Indeed, QED (the marriage of quantum theory and SR) is the most accurate theory ever devised by man.

You need to take some courses in physics, especially electrodynamics.

geistkiesel

Jun14-04, 02:56 AM

grounded

Jun14-04, 06:33 PM

Geistkiesel Wrote: Can you estimate the correction to the MM experiments when the earth velocity is added?

What type of correction are you looking for? Since there is no ether (at least none with resistance), the velocity of the earth or the source is not important. Light travels in all directions at the same speed. The Michelson-Morley experiment was designed to show the resistance light encountered while traveling with or against the ether. Since there is no resistance, the experiment failed to detect it. The only reason a correction would be needed is to sustain the belief in the resistance, such as the Lorentz-Fitzgerald contraction. No matter how fast the earth is traveling, any ray of light used in the experiment will travel the same speed going straight as it would if reflected 90-degrees.

grounded

Jun14-04, 06:46 PM

TOM MATTSON

Can I pick your brain again?

Is it that you don’t believe the number of cycle on the screen of an oscilloscope will increase as you increase speed towards the source?

Or is it that you don’t believe the distance the observer has traveled has to be included when making relative measurements?

russ_watters

Jun14-04, 09:25 PM

Is it that you don’t believe the number of cycle on the screen of an oscilloscope will increase as you increase speed towards the source? An oscilloscope has nothing to do with the speed of light. When moving toward a source, there is a red-shift, and if its enough, you would see more cycles on the oscilloscope, but that doesn't tell you anything about C.

ram2048

Jun14-04, 10:58 PM

your hypothesis about light and wavelengths is incorrect i think. i'm not going to go into what "I" personally believe on the matter, because i already have alot of stuff on my plate at the moment <grin>

the frequency of the wave is not merely the wave length, although that is one way to look at it. it is how often the wave completes a cycle in a given time, say 1 second.

now suppose you're stationary looking towards a light source with your eyes open. you're taking in that light as a specific frequency meaning let's say arbitrarily 5 waves per second.

moving TOWARDS the light, you're catching them as you approach, meaning at extremely high speeds you're catching more waves per second. if you moved at a velocity equal to 1/2 lightspeed second towards the source you'd catch 1/2 as many more waves than you would if you were stationary.

of course you wouldn't KNOW you were moving towards the lightsource in an SR relativistic frame, so you would just "perceive" light as being a different wavelength/frequency in that "reality"

Tom Mattson

Jun15-04, 11:19 AM

Is it that you don’t believe the number of cycle on the screen of an oscilloscope will increase as you increase speed towards the source?

Not at all. If you move towards a source, you will definitely see that the frequency of the radiation is Doppler shifted such that the frequency increases.

Or is it that you don’t believe the distance the observer has traveled has to be included when making relative measurements?

The distance traveled by the observer only has to be taken into account when we want to translate the data taken from measurements to actual coordinates of events in spacetime. This is because it takes a finite time for information to propagate from an event to an observer.

grounded

Jun15-04, 03:53 PM

The distance traveled by the observer only has to be taken into account when...

When measuring the relative speed between two objects wouldn't the distance traveled by both objects in the same amount of time always have to be included?

An observer traveling towards a source of light will measure an increase in frequency. We call this Doppler shift, which is cause by passing the wavelengths (the full lengths) at a faster rate. We also measure a decrease in wavelength, which is said to be an effect of the relativity.

What I see is that the only reason we measure a decrease in the wavelength is because we are not including the distance the observer has traveled.

If the distance the observer has traveled relative to the source is included, then the wavelength will not change and the speed of light will not be constant. The only reason we measure the speed of light to be constant is because we measure a change in the wavelength.

Run some real or theoretical experiments with the formulas below and see what you find.

Change in frequency:
The amount of change in the measured frequency caused by the observer’s speed relative to the source is equal to the distance the observer has traveled relative to the source in one second (“positive when traveling towards the source” “negative when traveling away from the source”), divided by the known wavelength.

Observer’s speed:
The speed of the observer (relative to the source) equals the measured frequency multiplied by the known wavelength, minus the speed of light.

Measured frequency:
The measured frequency equals the speed of light added to the speed of the observer relative to the source (“positive when traveling towards the source” “negative when traveling away from the source”), divided by the known wavelength.

True wavelength:
The wavelength (relative to everyone) equals the speed of the observer relative to the source (“positive when traveling towards the source” “negative when traveling away from the source”) added to the speed of light, divided by the measured frequency.

Tom Mattson

Jun15-04, 04:11 PM

When measuring the relative speed between two objects wouldn't the distance traveled by both objects in the same amount of time always have to be included?

I was taking the observer's speed to be an independent variable. If you determine the speed by determining the distance traveled and the time elapsed, then yes you need to know the distance.

An observer traveling towards a source of light will measure an increase in frequency. We call this Doppler shift, which is cause by passing the wavelengths (the full lengths) at a faster rate. We also measure a decrease in wavelength, which is said to be an effect of the relativity.

OK

What I see is that the only reason we measure a decrease in the wavelength is because we are not including the distance the observer has traveled.

But from the observer's point of view (the one who is measuring the wavelength), he hasn't moved at all. It's the source that is moving towards him.

If the distance the observer has traveled relative to the source is included, then the wavelength will not change and the speed of light will not be constant. The only reason we measure the speed of light to be constant is because we measure a change in the wavelength.

Run some real or theoretical experiments with the formulas below and see what you find.

But the speed of light will be constant. It has been measured to be independent of the motion of the source in measurements from the decay of fast particles.

Change in frequency:
The amount of change in the measured frequency caused by the observer’s speed relative to the source is equal to the distance the observer has traveled relative to the source in one second (“positive when traveling towards the source” “negative when traveling away from the source”), divided by the known wavelength.

This is nonsense. A change in frequency cannot be equal to the change in the observer's distance. The two quantities don't even have the same units.

Observer’s speed:
The speed of the observer (relative to the source) equals the measured frequency multiplied by the known wavelength, minus the speed of light.

This is also nonsense. The frequency times the wavelength is the speed of light. Your formula says that, no matter what, the speed of the observer relative to the source is zero.

Measured frequency:
The measured frequency equals the speed of light added to the speed of the observer relative to the source (“positive when traveling towards the source” “negative when traveling away from the source”), divided by the known wavelength.

Which "known wavelength" is that? The one measured by the observer, or the one measured by someone at rest relative to the source?

True wavelength:
The wavelength (relative to everyone) equals the speed of the observer relative to the source (“positive when traveling towards the source” “negative when traveling away from the source”) added to the speed of light, divided by the measured frequency.

There is no "true wavelength, relative to everyone".

grounded

Jun15-04, 05:56 PM

TOM MATTSON wrote:
But from the observer's point of view (the one who is measuring the wavelength), he hasn't moved at all. It's the source that is moving towards him.
Then you must include the distance the source has moved towards the observer, it doesn't matter.

But the speed of light will be constant. It has been measured to be independent of the motion of the source in measurements from the decay of fast particles.
But did they include the distance that our measuring equipment has traveled relative to the source of the light? Or put another way, did they include the distance the source traveled relative to the test equipment?

This is nonsense. A change in frequency cannot be equal to the change in the observer's distance. The two quantities don't even have the same units.
The amount of change in the measured frequency caused by the observer’s speed relative to the source is equal to the distance the observer has traveled relative to the source in one second (“positive when traveling towards the source” “negative when traveling away from the source”), divided by the known wavelength.

The answer is the number of additional cycle measured per second, or the reduction.

This is also nonsense. The frequency times the wavelength is the speed of light. Your formula says that, no matter what, the speed of the observer relative to the source is zero.
The speed of the observer (relative to the source) equals the measured frequency (measured by the observer) multiplied by the known wavelength, minus the speed of light.

The known wavelength is the wavelength measured while at rest compared to the source.

There is no "true wavelength, relative to everyone".
The only way to measure a changing wavelength is by not including the distance the observer has traveled towards the source, or the distance the source has traveled towards the observer.

Tom Mattson

Jun15-04, 06:14 PM

Then you must include the distance the source has moved towards the observer, it doesn't matter.

Even so, there is still a measurable change in wavelength.

But did they include the distance that our measuring equipment has traveled relative to the source of the light? Or put another way, did they include the distance the source traveled relative to the test equipment?

Yes.

The amount of change in the measured frequency caused by the observer’s speed relative to the source is equal to the distance the observer has traveled relative to the source in one second (“positive when traveling towards the source” “negative when traveling away from the source”), divided by the known wavelength.

The answer is the number of additional cycle measured per second, or the reduction.

Right, I hit "send" before going back to complete that sentence. So, it's a distance divided by a distance, which sets a frequency equal to a quantity with no units at all. Unless, of course, you mean to say that it is not the distance divided by a wavelength, but a speed divided by a wavelength.

Is that it?

The speed of the observer (relative to the source) equals the measured frequency (measured by the observer) multiplied by the known wavelength, minus the speed of light.

The known wavelength is the wavelength measured while at rest compared to the source.

But why should we combine those quantities to form a speed? A main point of SR is that we cannot take it for granted that we can combine quantities taken from different inertial frames.

The only way to measure a changing wavelength is by not including the distance the observer has traveled towards the source, or the distance the source has traveled towards the observer.

No, you measure a changing wavelength simply by measuring the wavelength of light when you are in different states of motion relative to the source. Taking the motion of the source relative to the observer into account doesn't give you the "real" wavelength in your frame, it gives you the wavelength in the rest frame of the source.

Tom Mattson

Jun15-04, 06:34 PM

I'm guessing that the following idea of yours is what is most preventing you from accepting SR.

The only way to measure a changing wavelength is by not including the distance the observer has traveled towards the source, or the distance the source has traveled towards the observer.

And I responded thusly:

No, you measure a changing wavelength simply by measuring the wavelength of light when you are in different states of motion relative to the source. Taking the motion of the source relative to the observer into account doesn't give you the "real" wavelength in your frame, it gives you the wavelength in the rest frame of the source.

To that I will add that you could make your claim about any measurable quantitiy that varies from frame to frame. You could say that the only way that time dilates is because we don't include the relative motion between muons and our laboratory. Thus, they don't really take longer to decay, and we can prove that if we just calculate back to what the muon lifetime is in its own frame.

Well no kidding!

Yes, you can always calculate proper times, lengths, wavelengths and frequencies by transforming back to the rest frame of the object under study, be it a muon, a meter stick, or a light source. But just because we can go back and calculate the values of those quantities, it does not imply that those values are somehow more "real" than the ones we measure.

You seem to be trying to get me to consider a universe in which SR is false. There's no need: I've already done it (I had to, as part of my studies). What you don't understand here is that you need to consider such a universe.

A universe in which Maxwell's equations look different in every frame.

A universe in which the momentum of a photon (which is inversely proportional to its wavelength) is independent of the state of motion of particles with which it collides.

A universe in which measurements of microscopic systems agree with relativistic qunantum theories vastly better than they do with nonrelativistic qunantum theories.

The longer you look at a "Universe without SR", the more you'll see that it is an illusion, and it is most definitely not the universe we live in. Do yourself a favor: Study some physics. You'll be the better for it.

grounded

Jun15-04, 08:27 PM

I'm guessing that the following idea of yours is what is most preventing you from accepting SR.

The reason I believe that is because of the following:

If the width of the screen of an oscilloscope represents a one-second-time period, then it will also represent 186,000 miles since that is the distance light travels in ones second. Right?

The number of cycles displayed on the screen is the number of cycles that has passed by in one second. If you take 186,000 miles and divide it by the number of cycles on the screen, it will equal the length of each cycle. Right?

If the width of the screen is six inches long, then six inches represents 186,000 miles, and 3 inches would represent 93,000 miles. Doing this we can apply a scale to the screen and measure the length of each cycle. Right? Although it would be difficult.

If the oscilloscope increases speed towards the source, the number of cycles displayed on the screen (relative frequency) will increase, and the length of each wave (relative wavelength) will decrease. And this is why you believe the wavelength has changed right?

The frequency increases because traveling towards the source has increased the total relative distance traveled in one second. The new frequency must be divided into the sum of 186,000 miles plus the distance the oscilloscope has traveled. Right? Relative speed divided by relative frequency equals relative wavelength, right?

The cycles appear closer together on the screen because the screen represents a greater area(the relative speed, or distance per second). It’s only by not adjusting the scale of the screen to represent the total distance traveled by the light and the observer that a change in wavelength can occur. If we do adjust the scale, the wavelength never changes. Do you think the scale of an oscilloscope needs to be adjusted when measuring light while in motion relative to the source?

grounded

Jun15-04, 08:47 PM

Tom

If you used an oscilloscope to measure a pulse emitted from the front of each boxcar as a train passes by you, the number of pulses on the screen will increase if the train speeds up or if you increase speed towards the train. The individual pulses will also be closer together on the screen, this does not mean the length of the boxcars has changed; it means the distance that the screen represents has been increased.

If you do not adjust the scale of the screen, then the relative speed of the train will never change.

russ_watters

Jun15-04, 09:20 PM

The individual pulses will also be closer together on the screen, this does not mean the length of the boxcars has changed; it means the distance that the screen represents has been increased. What, you've never heard of length contraction? Well, if you don't buy time dilation, I doubt you'll buy length contraction either, but....

...an observer in a moving boxcar will indeed measure the boxcar to be a different length than an observer on the ground.

Like Tom said, what you are doing is assigning a "proper" length in order to calculate speed. Sorry, but you can't do that. For the person in the boxcar, time and distance are what he measures them to be and for the person on the ground, time and distance are what he measures them to be. And they will not necessarily agree on the time and distance involved with the same event.

I must emphasize again that though it may seem counterintuitive to you, these phenomena have actually been observed to occur. They are reality.

Tom Mattson

Jun15-04, 11:19 PM

The reason I believe that is because of the following:

The reason you believe that is because you don't know anything about physics.

Take a few courses, and try to learn something. Either that, or open up to learning something about real physics here at Physics Forums, whether or not it defies your intuition.

If not, then you're just going to be another crackpot around here.

geistkiesel

Jun16-04, 12:45 AM

The reason you believe that is because you don't know anything about physics.

Take a few courses, and try to learn something. Either that, or open up to learning something about real physics here at Physics Forums, whether or not it defies your intuition.

If not, then you're just going to be another crackpot around here.

You use the lack of formally gathered knowledge "about the real physics" as a priest uses his call to faith. You are only superior in your own perception, a legend in your own mind only. I reject SR for philosophic reasons, primarily becasuse SR and SR spokes agents such as yourself, talk silly, deferentially,with the superiority of mathematical supremeacy. I reject SR and refuse to study the essence of the insanity for the same reason I don't put my finger in fires tio find out how hot it may be. Do you understand? All of your references to experimental proof of SR are understoof by myself as mantras of idiots.

Do you understand? I consider you a scientific clown. I want not what you have to offer.

I do not need your pemission to scrutinize any offered theory, nor do I need you permission, or support, to offer my own ideas, even though you and I both know, my ideas are guaranteed to remain unambiguosly contradictory to your ideas.

I reject your totality of expression, your scientific methods, your authoritative persona, I reject your smug educator's personality, I reject your mentorial status as having any useful significant additions to the exchange of ideas and the progress of science, I reject your every manifest breath, I reject your efforts to maintain the status quo in a state of blind obedient sleep-walking darkness.

I reject your contnued insistance that I have something owed to you.

Your reference to the "proof" that mass moving at .99c measured a value of c for the velocity difference of itself and light was ignored, unread.

You have a huge theoretical abyss to consider: Either pull up the drawbridge and defend the castle, or *demonstrate how moving toward oncoming photons shortens the wave length of the light, by demonstrating that the increase in frequency is other than your eye moving faster over the oncoming wave lengths and,
justification of suppressing the addition of the distance traveled by an observer to the wave length of the oncoming photons in the analysis of data from experiments measuring the constancy of the speed of light, and direct experimental results disproving the *Grounded claim in 2.) and 3.) above.

* See Grounded's Post #1 in this thread.

Hurkyl

Jun16-04, 07:18 AM

Tom Mattson

Jun16-04, 07:51 AM

All of your references to experimental proof of SR are understoof by myself as mantras of idiots.

That's just it: Nothing about SR is "understood by yourself".

The experimental and theoretical arguments in support of SR are overwhelming, and furthermore they are available for anyone to examine. How you can say, on the one hand, that I lack the formal knowledge of physics, and then on the other hand that you refuse even to look at SR seriously, is hypocritical beyond belief.

You're just another idiot with an internet connection, a bad attitude, and too much time on his hands.

geistkiesel

Jun16-04, 01:12 PM

That's just it: Nothing about SR is "understood by yourself".

The experimental and theoretical arguments in support of SR are overwhelming, and furthermore they are available for anyone to examine. How you can say, on the one hand, that I lack the formal knowledge of physics, and then on the other hand that you refuse even to look at SR seriously, is hypocritical beyond belief.

You're just another idiot with an internet connection, a bad attitude, and too much time on his hands.

You misrepresent myself with the claim that I refuse to look at SR seriously. Look at my posts and repeat the representations for all those visitng this thread that I do not take SR seriously? Why do I do this? For the sheer pleasure of poking at you and listening to your squealing?

You don't empress me as enjoying the minimum human qualities necessary for the title of scientist: consciousness of a mental state of objectivity, understanding, curiosity, patience, willingness to listen, to learn.

The most interesting, unique and creative post on this forum, in my humble and brief apearances and experience, is Grounded's essay regarding the measurement of light speed, wave length and frequency, among other subjects. Your response was basically that it is contrary to SR, ergo its wrong. Your inability to discuss the essay on its own merits exposes your weakness as a claimed scientist(s). If it ain't SR it ain't in your dictionary and therefor by the dictates of SR you must, "cut it out and kill it" to quote Gen. Colin Powell in the midst of Desert Storm.

Demonstrate your expertise as a scientist on the issues, demonstrate your wisdom, your knowledge, your keen sense of analytic acuity. Prove it, in other words.

You have a huge theoretical abyss to consider: regarding Grounded's claims he shows us in his essay: That an observer's velocity wrt to the source of photons is complex and guided by:
FL - c. F is frequency, L the wavelength and c the speed of light.
the frequency F = (c + v)/L where v is the observer's velocity wrt the source.
change of frequency = (D/sec)/L where D is the distance moved per sec wrt the source and,

the wave length L = v/ F where v is the velocity of the observer wrt source.

This may be too overwhelming for you to consider in one fell swioop, so take just the simple measurement of frequency that Grounded suggests: When an observer moves against the stream of photons the wave length of the photons do not become squeezed or shortened, the frequency increase is the increase in observed rate the individual wave lengths pass through the eye as the observer moves. The wave length remains invariant to the observation, neat isn't it. The observer puts no force, or pressure on the wave of the light. The speed of light is constant, but is certainly not as SR predicts with its built in errors in scientific and physical law, the relative speed of light is frame dependent. This is where I start, and until proved otherwise, this is where I shall remain. Do you understand?

This discussion regarding frequency was discarded out of hand, without the deliberation and care it deserves, so .

1. Either pull up the drawbridge and defend the castle, or
2. *demonstrate how moving toward oncoming photons shortens the wave length of the light, by demonstrating that the increase in frequency is other than your eye moving faster over the oncoming wave lengths and,
3. justification of suppressing the addition of the distance traveled by an observer to the wave length of the oncoming photons in the analysis of data from experiments measuring the constancy of the speed of light, and
4. direct experimental results disproving the *Grounded claim in 2.) and 3.) above.

So once again you have the opportunity to answer some serious questions necessitated by *Grounded's essay, the opening of this thread, in this fiorum of Theory Development, the name of the game.

geistkiesel

Jun16-04, 01:50 PM

What about your own faith, Geistkiesel? It must be pretty strong for you to continue to have your unwavering belief in the incorrectness of Special Relativity.

I mean, if I had a strong conviction against learning something, I would resign myself to the fact that I don't know that thing.

Well Hurkyl ol' pal, that then marks one of the differences between yourself and myself, doesn't it?.

But here you are, steadfastly refusing to learn Special Relativity, refusing to hear evidence confirming it, and you are able to stick to your conviction that it cannot possibly be anywhere close to valid!

You think I am totally ignorant of SR? Hurkyl you forget the number of posts we have exchanged? You think nothing rubs off on to me? The average PhD specializing in SR takes how long Hurkyl? Should dissidents go through the same jumping of hoops just be qualified to discuss SR? I have said on at least a dozen occasions that I am fully convinced that SR predicts what you say it predicts. I do not say this out of hand. I believe you when you make a claim that you are being honest in what you clainm SR is and what it does.

Wait, I'm wrong, you're not so much sticking to your convictions; you never face any scrutiny because you denounce anyone who would scrutinize you as being in a "state of blind obedient sleep-walking darkness".

You misuse the quote. Tis you methodology, your demontrated impatience with any who disagree, your intention to gain converts or to shut up detractors is your manifest mission. Your manifest state of maintaning SR at any cost, even the cost of your own lost souls is distressing, but then I gave up saving the world long ago, in 1998, if I remember. . See hurkyl, there you go again. You know I don't denounce any who scrutinize me a "obedient sleep-walkers". I do apply the anlogy when I see it applicable. By the way have you read Kessler's book "The Sleepwalkers"? An historical account of Copernicus, Tycho, Kepler and Galileo?

You still have your blind faith, but you don't have the confidence in your faith, so you need to belittle those who might erode your faith in order to maintain it.

What is this pot and kettle time? It is not faith that I base my rejection of SR. It uis what I have learned of it, a large exy=tent nof which is yoru doing. I belittel a bit too much, KI suppose, but it certainly is not a trait that escapes your mouth and the likes of my our colleague Tom Mattson is it? You aren't telling us that you were innocent of bellitlement practices until I came upon th escene and t6aught you how to do it are you?
Erode my faith, oh ye of so little of that, who dost first point his accusing finger. read on matey!

You liken learning SR to putting a finger in a fire. Why? Putting your finger in a fire can cause physical pain and injury; are you suggesting that you will suffer mental pain and injury if you tried to learn SR? Are you really that afraid you might be wrong?

No I said putting my finger in a fire would cause pain and injury to my finger. It was a metaphor, and exagerated metaphor at that. Are you seriously questioning my meaning and intent in using that phraseology in that line?

You see hurkyl, to my own satisfaction I have limited my time and energy as I see fit. It is my choice made with eyes wide open. You yourself have in your infinite patience and teaching expertise taught me sufficiently to know, to my own satiisfaction, that I am not going to study something with the intrinsic silliness built in that you yourself have shown me is the essential crucial thread of SR. And for this I will remain eternally grateful to you for that effort.
Is this plain enough for you to understand?

"The enemies of truth. Convictions are more dangerous enemies of truth than lies." :rofl:

There wasn't a lot (any) of science in your post. Are you getting tired hurkyl?

grounded

Jun16-04, 04:51 PM

What, you've never heard of length contraction? Well, if you don't buy time dilation, I doubt you'll buy length contraction either, but....

...an observer in a moving boxcar will indeed measure the boxcar to be a different length than an observer on the ground.

Like Tom said, what you are doing is assigning a "proper" length in order to calculate speed. Sorry, but you can't do that. For the person in the boxcar, time and distance are what he measures them to be and for the person on the ground, time and distance are what he measures them to be. And they will not necessarily agree on the time and distance involved with the same event.

I must emphasize again that though it may seem counterintuitive to you, these phenomena have actually been observed to occur. They are reality.

If the observer increases speed towards the train until the number of pulses on the screen has doubled, what does that tell you about the wavelength? The train was originally traveling towards you at 55 MPH. The pulses doubled because you are now driving 55 MPH towards the train. The distance between the pulses on the screen has been cut in half because the width of the screen now represents twice the distance. It now represents the distance traveled by the train and the observer. Right? Tell me you don't think that traveling 55 MPH will cut the length of the boxcars in half? If you don’t then you must agree that the scale of the screen must represent distance traveled by the train and the observer. By including the observer’s distance, we can calculate the actual length of the boxcar at any speed, relative to anyone.

Using the same oscilloscope to measure light, you will not read a change in wavelength if you include the distance the observer has traveled, just as with the train. Are you saying that an oscilloscope must include the distance traveled by the observer with all of our measurements, except light? You do realize that if the distance traveled by the observer is not included, then ANYTHING you measure will NEVER show a change in relative speed? If we include the distance when measuring light, the need for SR disappears since there is no change in the wavelength. The only way to measure a change in wavelength caused by the observer’s speed, is to ignore the distance the observer has traveled.

The wavelength is the distance light has to travel away from the source in order to complete one cycle. That length is the same whether you are there, or not. If you increase speed towards the light, you will pass over those lengths at a faster rate. They do not change in length as you increase speed, only the amount of time spent over each wave changes.

If you believe the observers speed does change the wavelength, then why can we only measure it when we ignore the distance the observer has traveled?

Alkatran

Jun16-04, 05:14 PM

The wavelength of light is not a relative measurement; it is the distance that the light has to travel away from the source in order to complete one wave. That distance is not determined by the observer’s speed, it is the same for all observers traveling at any speed or direction. The frequency of light is a relative measurement; it is the number of wavelengths the observer passes in one second. This number is determined by the speed of the observation and will be different between observers traveling at different speeds relative to the source. The wavelength of light is unaffected by the observers speed, any measured change in wavelength is an error that is caused by not including the distance the observer has traveled relative to the source. When calculating the wavelength, the distance that the light travels from the source in one second must be added to the distance the observer has traveled relative to the source in one second, and then divided by the measured frequency. If the distance the observer has traveled is not included, then the relative speed will never change since the total distance traveled would only include the distance the light has traveled.

Isn't the wavelength affect by the contraction of distances in the inverse way frequency is affected by time dilation? So that the wavelength of light is affected by the observer's speed?

grounded

Jun16-04, 05:46 PM

grounded

Jun16-04, 06:23 PM

Isn't the wavelength affect by the contraction of distances in the inverse way frequency is affected by time dilation? So that the wavelength of light is affected by the observer's speed?

There is no time dilations or contractions. The only reason people believe that is to explain why we measure a change in wavelength. Measuring this change is what keeps the relative speed constant. But the only reason we measure a change in wavelength is because the distance the observer has traveled relative to the source is never included.

We measure an increase in frequency because the total relative distance traveled in one second has increased, which simply means we are driving farther, therefore we are running into more wavelengths in the same amount of time. To calculate the wavelength, the new frequency must be divided into the total distance traveled by the light and the observer. Currently we only include the distance that the light has traveled. It is by not including the distance the observer has traveled that causes our measurements of the wavelength to change.

My previous post shows how when using a formula containing a RELATIVE wavelength, and a RELATIVE frequency, the RELATIVE speed, which is the total distance traveled by the light and the observer in one second, must also be used and not just the distance traveled by the light.

Maxwell only stated that the frequency is inversely proportionate to the wavelength because all types of light travel from the source at the same speed, which means the only difference between different types of light is their frequency and wavelength. Since frequency multiplied by the wavelength equals the speed, and all types of light travel from the source at the same speed, any light with a high frequency will have a short wavelength, and any light with a low frequency will have a long wavelength. He was not talking about relative measurements, he was merely describing the difference between different light sources.

Do you agree?

ram1024

Jun16-04, 06:35 PM

yep, i agree for the most part. except i would make calculations not towards the source, but towards the absolute space location the light was emitted at (not necessary if the source is stationary of course...)

Hurkyl

Jun16-04, 07:09 PM

Well Hurkyl ol' pal, that then marks one of the differences between yourself and myself, doesn't it?.

And the odd thing is we both think we have the better end of the deal.

You misuse the quote. Tis you methodology, your demontrated impatience with any who disagree, your intention to gain converts or to shut up detractors is your manifest mission. Your manifest state of maintaning SR at any cost, even the cost of your own lost souls is distressing, but then I gave up saving the world long ago, in 1998, if I remember.
You aren't telling us that you were innocent of bellitlement practices until I came upon th escene and t6aught you how to do it are you?

When facing those who make unjustified generalizations, I'm fond of returning the favor. My "impatience" is not the disagreement... you can check the history of my posts, I'm confident you'll find that I never belittle someone merely because of a disagreement or lack of understanding!

There wasn't a lot (any) of science in your post. Are you getting tired hurkyl?

Nor in yours; I find it interesting, from time to time, to debate the philosophy held by those I consider crackpots. Partly because I find it amusing, partly because I'm seriously curious why people think they way they do.

Alkatran

Jun16-04, 07:10 PM

I thought light moved relative to the observer, and that this had been proven time and time again? So that the observer can't have a speed relative to light other than c?

Tom Mattson

Jun16-04, 07:36 PM

You misrepresent myself with the claim that I refuse to look at SR seriously. Look at my posts and repeat the representations for all those visitng this thread that I do not take SR seriously?

I didn't misrepresent you, I simply paraphrased you. You specifically said that you refuse to learn SR, and your posts are consistent with that.

Why do I do this? For the sheer pleasure of poking at you and listening to your squealing?

I'm sure only you and your psychiatrist knows why you do this or anything else.

You don't empress me as enjoying the minimum human qualities necessary for the title of scientist: consciousness of a mental state of objectivity, understanding, curiosity, patience, willingness to listen, to learn.

I don't care if I impress you.

The most interesting, unique and creative post on this forum, in my humble and brief apearances and experience, is Grounded's essay regarding the measurement of light speed, wave length and frequency, among other subjects.

It was creative, I'll give you that. That doesn't make it true, though.

Your response was basically that it is contrary to SR, ergo its wrong.

It is you who is misrepresenting me. Go back and read what I wrote again. I refer not only to SR, but also to the experiments that confirm SR and simultaneously falsfiy grouded's ideas.

Your inability to discuss the essay on its own merits exposes your weakness as a claimed scientist(s).

I did discuss it on its own merits. Grounded's prediction is that the speed of light is not the same in every reference frame. I cited experimental evidence to the contrary. If my discussion of the essay "on its own merits" was brief, it's because that's all the discussion it merited.

Demonstrate your expertise as a scientist on the issues, demonstrate your wisdom, your knowledge, your keen sense of analytic acuity. Prove it, in other words.

I have demonstrated it many times, in many threads. But what difference would it make to you if I did it again? You don't listen to me anyway. You ask me to "prove it", but then when I do you just make some idiotic comment before dismissing it.

You have a huge theoretical abyss to consider:

No, I don't. You do, and I have already detailed it. The ironic thing is that the shortcoming that both you and grounded have is the very shortcoming he accused "us" of in his opening post:

Neither one of you understands how light propagates.

That's why I keep saying, "study some electrodynamics". If SR is wrong, then the propagation of light should only be possible in the rest frame of the source. Observers in any other frame will not detect the light as light. This is the very problem that led Einstein to come up with SR. The fact that you have no appreciation for the problem, and are content to run roughshod right over it, is why you are a crackpot.

This may be too overwhelming for you to consider in one fell swioop, so take just the simple measurement of frequency that Grounded suggests:

I don't have to consider it all at once, because I have considered it all before already. I've studied classical mechanics, with Galilean relativity and with SR, in great detail. I already know that physics without SR doesn't work. You, on the other hand, have a lot of learning to do before you are qualified to make any judgment on the subject. The question is, "will you?"

Tom Mattson

Jun16-04, 07:48 PM

Neither one of you understands how light propagates.

And this is what I mean by that:

In any course in classical EM, we obtain the following equation that describes the propagaition of light:

From Maxwell's Equations to the EM Wave Equation:

Using the boldface ∂ for the "del" operator, Maxwell's equations in vacuo are:

∂xE+(1/c)∂E/∂t.....(1)
∂xB-(1/c)∂E/∂t.....(2)
∂.E=0.....(3)
∂.B=0.....(4)

Making use of the vector identity:

∂x∂xA=∂(∂.A)-∂2A,

We can take the curl of equation (1) to obtain:

∂x∂xE+(1/c)(∂/∂t)∂xB=0
∂(∂.E)-∂2E+(1/c)(∂/∂t)∂xB=0

The part in blue vanishes by virtue of equation (3), and the part in red can be rewritten as -(1/c)∂E/∂t, by virtue of equation (2).

This gives us:

∂2E-(1/c2)∂2E/∂t2=0,

which is a wave equation. Taking the curl of equation (2) and following a similar path will show you that B satisfies the exact same wave equation.

We know this is a wave equation because, when we solve it, we get...

Solutions of the EM Wave Equation:

The components of the plane wave solutions of the wave equation are of the form:

Ai(x,t)=Ai0sin(k.x-wt+f)

where w/|k|=c. Since the solutions have constant phase, we can derive the speed of the waves to be c.

Now, if we assume that Galilean relativity is right, and all those effects predicted by SR don't really exist (despite the fact that they've been confirmed experimentally many, many times), we get:

Why Galileo and Maxwell Can't Both Be Right:

If electrodynamics is to be reformulated so that it is Galilean invariant, then the resulting equations will not be Maxwell's equations.

Here's what the reference from Jackson has to say about it. First, assume Galilean relativity. For a moving frame S' and a stationary frame S, we have:

x'=x-vt
t'=t

Let the wave equation hold in frame S. What does it look like in S'? We can derive that as follows:

∂/∂x=(∂x'/∂x)∂/∂x'=∂/∂x'
∂/∂y=(∂y'/∂y)∂/∂y'=∂/∂y'
∂/∂z=(∂z'/∂z)∂/∂z'=∂/∂z'

∂/∂t=(∂x'/∂/t)(∂/∂x')+(∂y'/∂t)(∂/∂y')+(∂z'/∂t)(∂/∂z')+(∂t'/∂t)(∂/∂t')
∂/∂t=v.∂'-(1/c)∂/∂t'

Squaring each operator and writing the equation in the coordinates of S' yields:

(∂'2-(1/c2)(∂2/∂t'2-(2/c2)v.∂'(∂/∂t')-(1/c2)(v.∂)2)Ai=0

where Ai is any component of either the E or B field.

Notice that the above equation is not a wave equation. That means that, if Galilean relativity is correct, then radio waves emitted from towers should become non-waves when you are driving in your car.

If Galilean relativity is correct, then you should not be able to listen to the radio in your car.

Why the Correctness of Maxwell Implies the Correctness of Einstein:

The Lorentz transformation, on the other hand, does preserve the form of the EM wave equation.

SR predicts the everyday observation that EM waves are EM waves in every frame. Galilean relativity, on the other hand, fails miserably here.

And to Wrap Up:

This is what none of the preachers of the Anti Relativity Religion understand. Einstein did not pull length contraction and time dilation out of thin air. They are logically derived consequences of the requirement that the EM wave equation and the speed of light be the same in every frame. The original paper was not even called, "Intro to Special Relativity", it was called, "On the Electrodynamics of Moving Bodies".

Like it or not folks, relativity is correct. If any of you wants to convince thinking persons otherwise, then you will have to argue on these terms, because these are the terms in which relativity was formulated.

Now, who can argue with that post on its merits?

grounded

Jun16-04, 09:06 PM

I will admit that I have no idea what any of that means. I will tell you that I came here specifically to talk to professionals in the field. I wanted to get your opinions on some simple concepts. The main question I have (as you know) is why we have to include the distance the observer has traveled when we measure everything but light. Doesn’t that seem odd? Especially since if we measure light like we measure everything else, the wavelength does not change.

I hate to keep repeating myself and I don’t want you to think that I will ask until you agree. But to tell me that other people have measure a change in wavelength doesn’t answer my question since they do not include the observer’s distance traveled.

What I want to do is ask what YOU think about the observer’s distance and show the repercussions of each choice. Both can be measure and calculated.

The math you have learned will show you what an oscilloscope will measure when the distance the observer has traveled is not included. You will always be right as long as the one-second screen of the oscilloscope represents 186,000 miles.

The math I use includes the distance the observer has traveled. The one-second screen of my oscilloscope represents 186,000 miles plus the distance the observer has traveled (or minus if traveling away from source). The oscilloscope will show a change in frequency and speed, but not wavelength.

Who is right since both can be measured and calculated? You have to admit that SR requires you to jump through a lot of hoops to explain why the wavelength changes. All I ask is that we account for the relative motion of the observer.

If you are not offended, I sure would like your response to my last two posts?

Alkatran

Jun16-04, 10:02 PM

You have to admit that SR requires you to jump through a lot of hoops to explain why the wavelength changes.

Just because something is more complicated than a method that will work (in this SPECIFIC situation) doesn't mean it is wrong. Relativity applies to more situations, so it is considered correct. At least that's my understanding.

russ_watters

Jun16-04, 11:27 PM

If you are not offended, I sure would like your response to my last two posts? Unfortunately, your thread has kinda been hijacked. Lets try to get it back on track. If the observer increases speed towards the train until the number of pulses on the screen has doubled, what does that tell you about the wavelength? The train was originally traveling towards you at 55 MPH. The pulses doubled because you are now driving 55 MPH towards the train. The distance between the pulses on the screen has been cut in half because the width of the screen now represents twice the distance. It now represents the distance traveled by the train and the observer. Right? Tell me you don't think that traveling 55 MPH will cut the length of the boxcars in half? Good so far. No, I'm not suggesting that the length of the boxcars is cut in half. What you have described is Galilean Relativity and it works reasonably well if you don't require too much accuracy.

But here's the thing: if you mount atomic clocks on your train and next to the observer, you'll find discrepancies between the clock rates. You'll also find that you always measure the same speed of light, no matter how you measure it (along the side of the tracks, on the train, from the tracks to train). But Galilean Relativity says that if the train is moving at you at 55mph, then the speed of light should be 55mph higher than normal on a signal sent from the train to the observer next to it (in front of it).

Its the ping pong ball analogy: a bouncing ping pong ball on a train has a different velocity according to a person on the train (maybe its bouncing straight up and down) than it does to a person next to it (bouncing up and down and moving forward at 55mph). Light particles are just really fast moving ping pong balls. Right...?

...Well that's what scientists used to think before they started measuring the speed of light to a precision at which you'd notice its variability. They found that its always the same. So that's a problem for Galilean Relativity.

As it turns out, this issue can be resolved by assuming a constant speed of light (its ok to assume it because its been measured) and a variable rate of the passage of time. But wait - since distance=speed times time, if the observers agree on the speed light traveled at but not the time, they will also not agree on the distance it traveled. Thats right, by implication, two observers will not necessarily agree on the distance between two objects/events - and that includes the length of the train itself.

These implications are hard to fathom when looking at a train. And for a human looking at a slow-moving train, they are irrelevant. You can't notice the difference. But for a faster moving object with an accurate clock, these effects become huge. GPS satellites contain clocks that have their rate adjusted according to Einstein's Relativity before launch so they remain in sync once in orbit. Lemme say that again: a GPS clock, capable of keeping time to within a couple of nanoseconds per day, does not keep good time when sitting on the ground. These effects are real and accounting for them is essential to the operation of the GPS system.

russ_watters

Jun16-04, 11:50 PM

My above post is a lot to chew on, but lemme at least give you some short answers to some of your other questions.

BTW: I will admit that I have no idea what any of that means. I will tell you that I came here specifically to talk to professionals in the field. I wanted to get your opinions on some simple concepts. A statement like that shows you have a great attitude - you're willing to learn. Good start. My previous post shows how when using a formula containing a RELATIVE wavelength, and a RELATIVE frequency, the RELATIVE speed, which is the total distance traveled by the light and the observer in one second, must also be used and not just the distance traveled by the light. If you have information such as your measured wavelength and your measured speed for the source, you can indeed calculate how the wave would appear to an observer stationary with respect to the source (or to any other observer given the relative speeds involved). I think what the other guys were trying to tell you is that if you don't know anything about distance or relative motion, you won't have any idea what the source thinks its wavelegth is - and thats ok. Any two observers may measure different and equally valid, wavelengths. If the observer increases speed towards the train until the number of pulses on the screen has doubled, what does that tell you about the wavelength? The train was originally traveling towards you at 55 MPH. Part of the problem with this analogy is that a train is sloooow with regard to the speed of light. To get half the wavelength (in Galilean Relativity), that train has to be traveling at half the speed of light. At such speeds, time dilation and length contraction are noticeable in human time and distance scales.To calculate the wavelength, the new frequency must be divided into the total distance traveled by the light and the observer. The problem is (and this is true in Galilean Relativity too as seen in the ping pong ball thought experiment), two observers wil not necessarily agree on that distance. What I want to do is ask what YOU think about the observer’s distance and show the repercussions of each choice. Both can be measure and calculated.

The math you have learned will show you what an oscilloscope will measure when the distance the observer has traveled is not included. You will always be right as long as the one-second screen of the oscilloscope represents 186,000 miles.

The math I use includes the distance the observer has traveled. The one-second screen of my oscilloscope represents 186,000 miles plus the distance the observer has traveled (or minus if traveling away from source). The oscilloscope will show a change in frequency and speed, but not wavelength.[/qutoe] Here's the problem: since distance and time are relative, (and in Galilean Relativity, distance is relative), using time from one frame and distance from another doesn't fit the definition of "speed." Both forms of relativity say the laws of the universe are the same for all observers: so speed has to be your measured distance and your measured time. Otherwise you could arbitrarily pick any distance and any time for any event and come up with any answer you like. Don't think so? - is that train moving at 55mph or 0mph? To a person on the train, the train is stationary. To a person next to it, its moving at 55mph. Who is right? Both. What if I tell you I can throw a baseball at 110mph becasue I throw it forward at 55 and the train is moving at 55? Will you accept that I throw harder than Randy Johnson? How about 1055mph due to the rotation of the earth? You won't because its an apples-to-oranges comparison of speeds and distances measured in different frames.
[QUOTE]You have to admit that SR requires you to jump through a lot of hoops to explain why the wavelength changes. All I ask is that we account for the relative motion of the observer. Well here's the thing about SR - its really quite elegant. SR says only two things:

-The laws of the universe are the same for any observer, regardless of inertial (non-accelerating) frame of reference.

-The speed of light is constant.

Thats it. No hoops. All of the implications follow directly from these two premises.

geistkiesel

Jun17-04, 06:57 AM

My above post is a lot to chew on, but lemme at least give you some short answers to some of your other questions.

BTW: A statement like that shows you have a great attitude - you're willing to learn. Good start. If you have information such as your measured wavelength and your measured speed for the source, you can indeed calculate how the wave would appear to an observer stationary with respect to the source (or to any other observer given the relative speeds involved). I think what the other guys were trying to tell you is that if you don't know anything about distance or relative motion, you won't have any idea what the source thinks its wavelegth is - and thats ok. Any two observers may measure different and equally valid, wavelengths. Part of the problem with this analogy is that a train is sloooow with regard to the speed of light. To get half the wavelength (in Galilean Relativity), that train has to be traveling at half the speed of light. At such speeds, time dilation and length contraction are noticeable in human time and distance scales. The problem is (and this is true in Galilean Relativity too as seen in the ping pong ball thought experiment), two observers wil not necessarily agree on that distance. [quote]What I want to do is ask what YOU think about the observer’s distance and show the repercussions of each choice. Both can be measure and calculated.

The math you have learned will show you what an oscilloscope will measure when the distance the observer has traveled is not included. You will always be right as long as the one-second screen of the oscilloscope represents 186,000 miles.

The math I use includes the distance the observer has traveled. The one-second screen of my oscilloscope represents 186,000 miles plus the distance the observer has traveled (or minus if traveling away from source). The oscilloscope will show a change in frequency and speed, but not wavelength.[/qutoe] Here's the problem: since distance and time are relative, (and in Galilean Relativity, distance is relative), using time from one frame and distance from another doesn't fit the definition of "speed." Both forms of relativity say the laws of the universe are the same for all observers: so speed has to be your measured distance and your measured time. Otherwise you could arbitrarily pick any distance and any time for any event and come up with any answer you like. Don't think so? - is that train moving at 55mph or 0mph? To a person on the train, the train is stationary. To a person next to it, its moving at 55mph. Who is right? Both. What if I tell you I can throw a baseball at 110mph becasue I throw it forward at 55 and the train is moving at 55? Will you accept that I throw harder than Randy Johnson? How about 1055mph due to the rotation of the earth? You won't because its an apples-to-oranges comparison of speeds and distances measured in different frames.
Well here's the thing about SR - its really quite elegant. SR says only two things:

-The laws of the universe are the same for any observer, regardless of inertial (non-accelerating) frame of reference.

-The speed of light is constant.

Thats it. No hoops. All of the implications follow directly from these two premises.

I read Grounded's methodology as adding a twist unconsidered by SR. All of his suggested calculations while heretical to a casual observer, have not been scrutinized directly and specifically. Tom_Mattson's mathematical models of ME and Galilean frames, while impressive, did not specifically address any of the measurment structures and issues suggested by Grounded.

This is a model screaming for an inside out analysis. The SR hammer has been used to its fullest and the model stil enjoys interest in potential development.

russ_watters

Jun17-04, 08:12 AM

I read Grounded's methodology as adding a twist unconsidered by SR. All of his suggested calculations while heretical to a casual observer, have not been scrutinized directly and specifically. Tom_Mattson's mathematical models of ME and Galilean frames, while impressive, did not specifically address any of the measurment structures and issues suggested by Grounded.

This is a model screaming for an inside out analysis. The SR hammer has been used to its fullest and the model stil enjoys interest in potential development.[emphasis added] We're pretty confident of what you'd find if you did the calculations. But feel free - no one is stopping you. Remember also, once you do the calculations using each model of Relativity, you have to compare them to reality (actual data - not your preconceived notion of what reality should be) to see which is right.

Tom Mattson

Jun17-04, 01:55 PM

The main question I have (as you know) is why we have to include the distance the observer has traveled when we measure everything but light.
Doesn’t that seem odd?

But as I said, there is absolutely no reason to say absolutely that the observer moves anywhere. We can fix him at the origin of his rest frame, and ask him what he measures for the wavelength of light that reaches him from moving sources. Yes, we can use that information to calculate what the measurement would be in the rest frame of the source. But as I said, it's not as if that latter wavelength is the real wavelength, while the others are only apparent.

Especially since if we measure light like we measure everything else, the wavelength does not change.

You have to be more specific about what "everything else" means. I certainly cannot measure the wavelength of light in the same way as I measure, say, barometric pressure.

I hate to keep repeating myself and I don’t want you to think that I will ask until you agree. But to tell me that other people have measure a change in wavelength doesn’t answer my question since they do not include the observer’s distance traveled.

And so the obvious question is, "Why should they include it?"

What I want to do is ask what YOU think about the observer’s distance and show the repercussions of each choice. Both can be measure and calculated.

That's easy: If you don't take the relative motion into account, and just use the raw measurement, you get the wavelength in the observer's frame. If you do take the relative motion into account, then you get the wavelength in the rest frame of the source.

The math you have learned will show you what an oscilloscope will measure when the distance the observer has traveled is not included. You will always be right as long as the one-second screen of the oscilloscope represents 186,000 miles.

I don't understand. Oscilloscopes don't have an axis for the distance traveled by the light.

The math I use includes the distance the observer has traveled. The one-second screen of my oscilloscope represents 186,000 miles plus the distance the observer has traveled (or minus if traveling away from source). The oscilloscope will show a change in frequency and speed, but not wavelength.

So, the math you use predicts the properties of the light in the rest frame of the source then.

Who is right since both can be measured and calculated?

They are both right, for the appropriate frame.

You have to admit that SR requires you to jump through a lot of hoops to explain why the wavelength changes.

SR does not require you to jump through any hoops. The problem is that you are looking at the consequences of SR (those being the Lorentz transformation, the relativistic Doppler shift, etc) without taking a serious look at the premises. SR was derived from requiring the invariance of the speed of light and the laws of EM theory from one inertial frame to another. I detailed the math in my last post. Once you understand how it arises and why it's necessary, it makes perfect sense.

All I ask is that we account for the relative motion of the observer.

And as I keep telling you, that will give you the values as measured in the rest frame of the source.

Tom Mattson

Jun17-04, 01:56 PM

Tom_Mattson's mathematical models of ME and Galilean frames, while impressive, did not specifically address any of the measurment structures and issues suggested by Grounded.

Yes, it does specifically address them. It says that the wavelength of light, which grounded believes to be an invariant under changes of inertial frame, is actually not invariant.

Tom Mattson

Jun17-04, 02:03 PM

I believe the formula below is correct, do you?

(RELATIVE SPEED) / (RELATIVE FREQUENCY) = (RELATIVE WAVELENGTH)

It's dimensionally correct, but it doesn't accurately describe light. If the speed of light varies from frame to frame, then you land squarely in the middle of the problem I detailed in my post on Maxwell's equations.

Keep in mind that the RELATIVE SPEED represents the total distance traveled by both the light (or the train), and the observer in one second.

This is what SR says:

(ONLY THE SPEED OF LIGHT) / (RELATIVE FREQUENCY) = (RELATIVE WAVELENGTH)

Right.

Don't you see the error in the above formula? The SR theory only explains why when using the above formula, the speed of light never changes. Isn't it obvious? How can the total distance traveled in one second ever change if the only distance included in your measurement is the distance light has traveled?

What, exactly, do you think is the error? If you are computing a speed, then yes, the only distance involved is the distance traveled by the light from the point of view of the observer. That's because speed equals distance traveled by time!

No matter how many wavelengths pass by you, you always divide them into the same distance. Do you find any logic in that?

What do you mean by, "divide them into the same distance"? We don't "divide" them into any distance. Since it is typically not wavelength but frequency that is measured, what we do is measure the frequency and divide it into the speed of light, not the distance the light has traveled. And the speed of light can be determined by using any distance that light travels, together with the time of flight.

reilly

Jun18-04, 12:40 AM

Grounded -- I suggest you study a first year physics text. Wave lengths and frequencies are defined to be inverses -- this is fundamental for any wave equation, including the second order wave equations that stem from the usual first order Maxwell equations. The invariance of Maxwell's eq.s under Lorentz transformations, a basic tenant of SR, guarantes that light will have the same speed in all inertial frames, that the various Doppler shifts occur, and that space and time measurements are different, generally speaking, for different observers.

Many have tried to poke holes in SR, but no one has come close to succeding. Often the poking comes from an incomplete or mistaken knowledge of SR. Sorry, but Einstein wins -- if you read his little book, the classic entitled Relativity, you will see why.
Regards,
Reilly Atkinson

geistkiesel

Jun18-04, 01:32 AM

geistkiesel

Jun18-04, 01:46 AM

I didn't misrepresent you, I simply paraphrased you. You specifically said that you refuse to learn SR, and your posts are consistent with that.

I'm sure only you and your psychiatrist knows why you do this or anything else.

I don't care if I impress you.

It was creative, I'll give you that. That doesn't make it true, though.

It is you who is misrepresenting me. Go back and read what I wrote again. I refer not only to SR, but also to the experiments that confirm SR and simultaneously falsfiy grouded's ideas.

I did discuss it on its own merits. Grounded's prediction is that the speed of light is not the same in every reference frame. I cited experimental evidence to the contrary. If my discussion of the essay "on its own merits" was brief, it's because that's all the discussion it merited.

I have demonstrated it many times, in many threads. But what difference would it make to you if I did it again? You don't listen to me anyway. You ask me to "prove it", but then when I do you just make some idiotic comment before dismissing it.

No, I don't. You do, and I have already detailed it. The ironic thing is that the shortcoming that both you and grounded have is the very shortcoming he accused "us" of in his opening post:

Neither one of you understands how light propagates.

That's why I keep saying, "study some electrodynamics". If SR is wrong, then the propagation of light should only be possible in the rest frame of the source. Observers in any other frame will not detect the light as light. This is the very problem that led Einstein to come up with SR. The fact that you have no appreciation for the problem, and are content to run roughshod right over it, is why you are a crackpot.

I don't have to consider it all at once, because I have considered it all before already. I've studied classical mechanics, with Galilean relativity and with SR, in great detail. I already know that physics without SR doesn't work. You, on the other hand, have a lot of learning to do before you are qualified to make any judgment on the subject. The question is, "will you?"

Tom_mattson we are getting nowhere by holding our credentials out to each other as some form of scintific proof. I surmise no one but us is really interested. The barn door has not been slammed shut so tightly that excludes possibilities unspoken or mispoken. If you are going to shake my tree a "crackpot" equivalence veil you throw over me is operating to you express disadvantage: Would you opt to accept a scintists support for you position who rejects another's positions based on a steaming allegation of crackpot?

I think you would deman more.

As a person who has spent a lifetime being the smartest one in the room, more often than not, I am always relieved when my relief shows shows up, usually saying sonething like,"Oh yeah?". You do sense the very deep responsibility you know I feel. Don't you Tom?

Tom you are my breath of fresh air. I wouldn't pass the mantle if I thought you unqualified, or hesitant to take the job out of a sense of wavering confidence. No, Tom, you've earned the position on your own merits. Me, I;m going to go lay down in the back of the bus for a spell.

geistkiesel

Jun18-04, 01:51 AM

Yes, it does specifically address them. It says that the wavelength of light, which grounded believes to be an invariant under changes of inertial frame, is actually not invariant.
I impliedly meant that the manipulating of grounded terms specifically were not addressed on its merits. If you see that I must agree with your stated perception. There is too much to investigate to accept/reject one or the other with such vehemence.

geistkiesel

Jun18-04, 01:57 AM

We're pretty confident of what you'd find if you did the calculations. But feel free - no one is stopping you. Remember also, once you do the calculations using each model of Relativity, you have to compare them to reality (actual data - not your preconceived notion of what reality should be) to see which is right.
Russ_watters let us assume i did the calculations and came up with sameanswers you would have provided and that I still rejected the hypothesis under scrutiny. Hard headed, dogmatic obvessive? OK what ever you see. The looking isn't over.

Tom Mattson

Jun18-04, 11:46 AM

You must consider that Grounded has made a number of choices that is transcendental to prevailing understanding.

But we can see that he isn't transcending anything. He is making choices that lead to the physics of the 19th century, and we know that those choices are wrong.

Tom Mattson

Jun18-04, 11:48 AM

Tom_mattson we are getting nowhere by holding our credentials out to each other as some form of scintific proof.

I'm not holding out my credentials in place of proof. I've presented an argument in this thread, and the only response I got to it was that from grounded, who admitted that he didn't understand any of it.

Tom Mattson

Jun18-04, 11:50 AM

I impliedly meant that the manipulating of grounded terms specifically were not addressed on its merits.

I know what you meant, and my answer stands. The argument I presented explains exactly why grounded cannot be right. What you and he need to do is study electrodynamics in order to understand the argument.

There is too much to investigate to accept/reject one or the other with such vehemence.

The only reason you consider this to be an open-ended research problem is because of the gap in your education.

wespe

Jun18-04, 12:23 PM

The main question I have (as you know) is why we have to include the distance the observer has traveled when we measure everything but light. Doesn’t that seem odd? Especially since if we measure light like we measure everything else, the wavelength does not change.

Others have replied but let me answer in simple terms of a layman.

I don't think we "include the distance the observer has traveled" for anything, where did you get that idea? You just measure and the result is valid according to yourself. The measured wavelength does not seem to change for ordinary objects moving at low speeds (and that's without any inclusion of traveled distance). What changes is the measured frequency and measured speed. The equation speed=frequencyxwavelength always holds true. But of course, when the speed is high, you see that the wavelength does change, according to length contraction. And the frequency changes according to relativistic doppler formula. Their product remains constant as c [for light, and always below c for objects with mass]. As I wrote in another thread, all these changes should be visible using an oscilloscope, so if relativity wasn't right, people would have discovered it.

Also, if you "include the distance the observer has traveled" for wavelength, you should also make the reverse calculation on frequency, and their product gives the speed according to source. So what?

russ_watters

Jun18-04, 12:23 PM

Russ_watters let us assume i did the calculations and came up with sameanswers you would have provided and that I still rejected the hypothesis under scrutiny. Hard headed, dogmatic obvessive? OK what ever you see. The looking isn't over. So, you're acknowledging that even in the face of clear and obvious information, generated by you, showing you are wrong, you will still believe yourself to be right? Wow. That brings up an interesting question: can someone be considered delusional if they know they are delusional?

And before you call that a personal attack, read the definition: Delusion (http://dictionary.reference.com/search?q=delusion) A false belief strongly held in spite of invalidating evidence. It sounds to me like you are saying if you ever got convincing evidence, you would choose to continue believing what you believe - and so you make every effort to avoid thinking about the evidence that exists.

Could you think about that for a minute, please?

grounded

Jun18-04, 05:32 PM

I am not sure anyone (except Geistkiesel) is trying very hard to understand what I have written. Special Relativity explains why we measure or calculate a change in wavelength while in motion relative to the source. What I have written explains that it is an error in measuring or calculating that causes us to measure or calculate a change in wavelength. Once this error is corrected, there is no change in the wavelength. If there is no change in the wavelength, then it makes no sense to use SR to prove me wrong. Think of it like this, we measure a change in wavelength and do not understand why. We then create a theory to explain why we measured a change. I am saying that we don’t need a theory to explain it since it was just a mistake in the way we measured/calculated it. I realize it sounds arrogant to say that everyone who has measured the speed of light has did it wrong, but I am asking you to put your emotions aside and take a rational look at it. As professionals you owe it to science to objectively view ideas from all perspectives despite your own prejudices. I am not asking you to agree with it, I am just asking you to understand it.

Anyone understanding my #1 post will realize that it is not really about SR. It is about the way we take measurements and how any motion between the object (being a car, a train, or light) and the test equipment will affect the results. I’m sure I will get ridiculed for this, but I want you to totally forget about Einstein and SR. If you are parked on the side of the road and a car passes by you at exactly 55MPH, and this is known to you, you can calculate the length of the car by knowing the amount of time it takes for the car to completely pass you. If it takes ¼ of a second to pass, then you know the car is 20.1666 feet long. This is because 20.1666 feet multiplied by 4 to find the distance traveled in one second equals 80.666 feet per second. 80.666 feet multiplied by 60 seconds equals 4,840 feet per minute. 4,840 feet multiplied by 60 minutes equals 290,400 feet per hour. 290,400 feet divided by 5280 (number of feet in mile) equals 55 MPH. Everyone should agree at this point.

This type of calculating will work every time. The only thing that will change this is if the car passing you changes speed, or you begin to move in your car. Now lets say you increased speed to a constant velocity of 10MPH towards the car that is going to pass you. Remember this has nothing to do with SR; it is only an examination of how we measure things. Here is what I want you to think about. How do you calculate the length of the passing car now that you are in motion? This is so basic it was probably the first thing they taught you in physics so you will have to go way back. The only way to accurately measure the length of the passing car while you are in motion is to account for the distance you have traveled. This is because you are trying to measure a length using a measured time period (the time it takes the car to pass) that is directly related to your speed. Increasing your relative speed reduces the amount of time it takes the car to fully pass you. It does not matter if you want to say you have increased speed, or the passing car has increased speed, as long as you account for the 10 MPH. If the 10MPH is not accounted for, then the speed of the passing car will never change and the length of the car will be reduced (sound familiar?). Everyone should still agree with me, just simple math, and here it is:

LENGTH OF THE PASSING CAR (wavelength)

(The distance the passing car travels in one second) (80.66 Feet)(This is a known value)
Added To:
(The distance you have traveled in one second) (14.66 Feet)
Then Multiplied by:
(The amount of time it takes ONE car to fully pass you) (.211538 Seconds)
Equals:
(The length of the car) (20.16 Feet)

TO FIND FREQUENCY (assuming there is chain of identical cars, bumper to bumper)

(Take 1)
Divided by:
(The amount of time it takes ONE car to fully pass you) (.211538 Seconds)
Equals:
(The number of cars that will pass in one second) (Or Frequency) (4.728 Cars)

TO FIND RELATIVE SPEED

(The distance the passing car travels in one second) (80.66 Feet)(This is a known value)
Added To:
(The distance you have traveled in one second) (14.66 Feet)
Equals:
(The relative speed between the 2 cars) (95.32 Feet per second)

TO FIND WAVELENGTH

(The relative speed between the 2 cars) (95.32 Feet per second)
Divided by:
(The number of cars that will pass in one second) (Or Frequency) (4.728 Cars)
Equals:
(The length of the car) (20.16 Feet)

TO FIND FREQUENCY

(The relative speed between the 2 cars) (95.32 Feet per second)
Divided by:
(The length of the car) (20.16 Feet)
Equals:
(The number of cars that will pass in one second) (Or Frequency) (4.728 Cars)

You should still agree with me, which means you must agree that the distance the observer has traveled must be included. Now lets take a look at what happens when we do not include the observer’s distance traveled:

This is what happens when you DO NOT include your distance traveled:

(Only the distance the passing car travels in one second) (80.66 Feet)(This is a known value)
Multiplied by:
(The amount of time it takes ONE car to fully pass you) (.211538 Seconds)
Equals:
(The length of the car) (17.06 Feet) We know this is wrong.

As I said in one of my earlier posts, the “amount of change to the length of the car” is equal to “the distance you have traveled”, divided by “the frequency”. (14.66 divided by 4.728 equals 3.1) (Also 3.1 added to 17.06 equals 20.16 which is the length of the car)
Take note that by not including your distance, you make the wavelength inversely proportionate to your frequency, which means the relative speed can never change. Sound familiar?

Even to this point everyone should still agree with me, all the above can be proved by anyone with a tape measure, a stopwatch, a calculator, and a couple cars.

The reason I wanted you to rationally integrate the above information without any SR prejudices, is so you can see how we ALWAYS have to include the distance traveled by the observer. This is a mathematical situation that takes place before Special Relativity. If SR is valid, then it should be measurable after accounting for the distance the observer has traveled.

If the distance the observer has traveled is not included when measuring cars, then you will measure a change in the length of the car that is inversely proportionate to the change in frequency, and the relative speed will never change.

If the distance the observer has traveled is not included when measuring light, then you will measure a change in the length of the wavelength that is inversely proportionate to the change in frequency, and the relative speed will never change.

Notice the similarities? Notice that the change in wavelength caused by not including the distance the observer has traveled equals the predicted change in wavelength using SR. The above math is correct, and is easily proven. I am pretty confident everyone will agree that when measuring cars, the distance the observer has traveled must be included. The question is why you wouldn’t include it when measuring light. To say we have to disregard it in order to measure the error that is caused by not including it, and then create a theory to explain it, is absurd. I would have no problem believing in SR if we could detect in while properly measuring for it. If you say my car scenario is invalid since it is not at relativistic speeds, then I ask you at what speed do you start ignoring the distance the observer has traveled?

For those of you who have never thought of the screen of an oscilloscope as representing a distance, consider the following. Light travels 186,000 miles in one second. If the screen of an oscilloscope (at rest relative to the source) represent a one second time period, then the screen will show all the cycles created by the light in one second. Since light travels 186,000 miles in one second and the screen represents one second, we can also say the width of the screen represents 186,000 miles since all the cycles on the screen multiplied by the wavelength will equal 186,000 miles. By applying a distance scale to the oscilloscope you can measure and see any change in wavelength on the screen. While in motion relative to the source, the distance that the screen represents must also include the distance the observer has traveled relative to the source (positive if towards, negative if away).

Also, the fact that you may not know the speed of the source (which I believe can be found using a spectrometer and a spectrograph) is irrelevant. Do the experiment with known values just as you would in the lab. Once the math is proven using known values, then it can be used to predict unknown values.

wespe

Jun18-04, 06:35 PM

I am not sure anyone (except Geistkiesel) is trying very hard to understand what I have written.
I'm reading/writing in a bit hurry, don't much time right now, but I can tell you are mistaken.

Special Relativity explains
let's forget SR effects since the involved speeds are low.

If you are parked on the side of the road and a car passes by you at exactly 55MPH, and this is known to you, you can calculate the length of the car by knowing the amount of time it takes for the car to completely pass you. If it takes ¼ of a second to pass, then you know the car is 20.1666 feet long. This is because 20.1666 feet multiplied by 4 to find the distance traveled in one second equals 80.666 feet per second. 80.666 feet multiplied by 60 seconds equals 4,840 feet per minute. 4,840 feet multiplied by 60 minutes equals 290,400 feet per hour. 290,400 feet divided by 5280 (number of feet in mile) equals 55 MPH. Everyone should agree at this point.

It would help if you used metric system and simpler numbers.. Like, if relative speed is 55 meters/second and it takes 1/5 seconds to pass you, then the length of the car is 11 meters.

This type of calculating will work every time. Now lets say you increased speed to a constant velocity of 10MPH towards the car that is going to pass you. Remember this has nothing to do with SR; it is only an examination of how we measure things. Here is what I want you to think about. How do you calculate the length of the passing car now that you are in motion?

OK now you know that the relative speed is 65 MPH, not 55, of course. Then, using the same method you described above, the wavelength is calculated the same.

With my numbers, if relative speed increased to 66, it would take 1/6 seconds for it to pass you, and again 11 meters is calculated.

have to go now..

Edit: I'm back.
OK, so I calculated above the same length when we incresed the relative speed. I did not account for the traveled distance. I just used the new relative speed (which is supposed to be known), and the measured time for passage of the car. Note that the speeds wrt the road are not needed anywhere, just like the distances traveled wrt the road are not needed. All you need is to make measurements on the passing car, while sitting in your car. You can also directly measure the wavelength of the passing car, by comparing it with your own car. So in fact you can directly measure all of them: the relative speed, relative wavelength, and relative frequency.

Tom Mattson

Jun18-04, 07:44 PM

I am not sure anyone (except Geistkiesel) is trying very hard to understand what I have written.

Grounded, we all understand it. That's because we all studied nonrelativistic physics before learning SR. It's just that you aren't understanding what we are saying. Let me explain.

Special Relativity explains why we measure or calculate a change in wavelength while in motion relative to the source. What I have written explains that it is an error in measuring or calculating that causes us to measure or calculate a change in wavelength.

What Russ and I have been telling you, and what you aren't understanding, is this:

The wavelength of the light in the rest frame of the source is not special. There's no reason to think that it is the "correct" wavelength, while all others are only "apparent". There's no reason whatsoever to use any correction for the distance the observer has traveled, and I'll explain why later on.

Once this error is corrected, there is no change in the wavelength. If there is no change in the wavelength, then it makes no sense to use SR to prove me wrong.

It does make sense to use SR to prove you wrong, because you yourself deduced from your hypothesis that the speed of light is not the same in every frame. And indeed, if your hypothesis is true, your deduction would be true also.

But the deduction is not true: The speed of light is the same in every frame.

I don't think you are seeing exactly how SR connects to your argument.

Think of it like this, we measure a change in wavelength and do not understand why. We then create a theory to explain why we measured a change. I am saying that we don’t need a theory to explain it since it was just a mistake in the way we measured/calculated it.

But the theory was not developed to account for wavelength measurements. The theory was developed for the exact reason I said it was developed: To maintain the invariance of the equations of electrodynamics when transforming from one inertial frame to another.

You said you came here to talk to professionals about this, yes? Please take the advice of this professional: You are never going to get out of these circles you are stuck running around in until you understand the problem above.

I realize it sounds arrogant to say that everyone who has measured the speed of light has did it wrong, but I am asking you to put your emotions aside and take a rational look at it.

No problem on my end. The question is, will you do the same?

As professionals you owe it to science to objectively view ideas from all perspectives despite your own prejudices. I am not asking you to agree with it, I am just asking you to understand it.

Understanding it is no problem. Your points are nothing new to me: physicists have to study nonrelativistic physics before learning SR. It's not that I don't understand you, it's that I understand that you are wrong.

Anyone understanding my #1 post will realize that it is not really about SR.

And now we come to Prejudice #1, that you must abandon if this is to make any progress. When you say that the speed of light is not the same to all observers, the logical implication is that Galilean relativity is correct and Special relativity is wrong. That is why I attempted to explain to you why this cannot be so. You can't state what you state on the one hand, and then refuse to listen to why it's wrong on the other, and expect this discussion to get anywhere.

It is about the way we take measurements and how any motion between the object (being a car, a train, or light) and the test equipment will affect the results. I’m sure I will get ridiculed for this, but I want you to totally forget about Einstein and SR.

I wish you were more interested in learning physics, because you would know that you would not be ridiculed for saying this. Do you know why?

Because I used the exact same approach in my post on Maxwell's equations.

I started with classical EM theory, and I assumed that SR was wrong, and I derived a prediction that is contrary to what we observe.

If you are parked on the side of the road and a car passes by you at exactly 55MPH, and this is known to you, you can calculate the length of the car by knowing the amount of time it takes for the car to completely pass you.

OK

This type of calculating will work every time. The only thing that will change this is if the car passing you changes speed, or you begin to move in your car. Now lets say you increased speed to a constant velocity of 10MPH towards the car that is going to pass you.

OK again.

The only way to accurately measure the length of the passing car while you are in motion is to account for the distance you have traveled.

Not OK.

You are wrong when you say that this is the "only way", and I know that I have explained it more than once in this thread. Please do what you ask of the rest of us and listen to our responses.

Again, with emphasis: There is no reason whatsoever to state that the observer has traveled any distance. Your statement reflects Prejudice #2, which you also must abandon: There is no way to even define absolute motion. We are not forced to say that the obserer is moving 10 MPH. We are perfectly free to say that the observer is at rest, and that the car under observation is moving towards him at 65 MPH (notice that I'm not taking SR into account). All the observer has to do is take the 65 MPH, multiply by the time required to pass, and we get the correct length.

All you have to do is use the relative velocity, and the time required for the car to pass, and you get the correct car length.

That is exactly what we do when we make measurements.

If the distance the observer has traveled is not included when measuring cars, then you will measure a change in the length of the car that is inversely proportionate to the change in frequency, and the relative speed will never change.

If the distance the observer has traveled is not included when measuring light, then you will measure a change in the length of the wavelength that is inversely proportionate to the change in frequency, and the relative speed will never change.

Notice the similarities?

Yes. But unlike you, I also notice the differences. This brings us to Prejudice #3, which you also must abandon if you are to see your way out of this error. Specifically, you are prejudiced towards the opinion that a stream of light pulses can be treated in the same way as a stream of cars. It can't!.

You are correct in saying that an observer errs in making a measurement of the length of the car using its ground speed of 55 MPH when the observer's own ground speed is 10 MPH in the other direction. The reason you are correct is that there is (according to pre-relativity) a relative velocity of 65 MPH between the two cars, and that is what must be used to get a correct result.

But what happens when we look at light? The relative speed never changes, no matter what the speed of the source. The relative velocity between a light pulse and any observer is c. And since the speed of light is the same for everyone, no frame has any special claim to knowledge of the "correct" wavelength of any light pulse. All measurements are equally valid for their respective frames.

Your entire case rests on a rejection of that fact, and that is why you are wrong.

edit: typo

geistkiesel

Jun18-04, 07:49 PM

But we can see that he isn't transcending anything. He is making choices that lead to the physics of the 19th century, and we know that those choices are wrong.
Tom Can you see an exact repetition of Grounded'd maths and 19th century maths, specific?, as opposed to philosophyc?

What possible harm is there to explore it?. Why not look at his agenda and go as far as you can with it? If you spend two weeks arguing and no dicsernible difference in positions, or making an effort to steer him where he wants to go without constantly whispering in his ear "yoiu are going to fail?" then what is the harm either way. You would certainly get a different point of view and as a prevailing mainliner you need it, the experience, I mean.

Tom Mattson

Jun18-04, 08:02 PM

Tom Can you see an exact repetition of Grounded'd maths and 19th century maths, specific?, as opposed to philosophyc?

Yes: He implicitly uses the Galilean velocity addition formula, which is known to be wrong.

What possible harm is there to explore it?. Why not look at his agenda and go as far as you can with it?

You either aren't reading, or aren't understanding my responses. I have explored the very same Galilean point of view held by Grounded, and I know exactly how far it goes: It runs itself into the ground. I do not know how to show it more explicitly than I already have.

If you spend two weeks arguing and no dicsernible difference in positions, or making an effort to steer him where he wants to go without constantly whispering in his ear "yoiu are going to fail?" then what is the harm either way.

First, our positions are diametrically opposite. That should be obvious to anyone who understands the issues involved. Second, the "harm" as you put it is letting scientific errors go uncorrected on a website that is supposed to be dedicated to scientific education. And third, I'm not telling him that he is "going to fail", I'm telling him that he is advocating a position that already has failed, over 100 years ago.

You would certainly get a different point of view and as a prevailing mainliner you need it, the experience, I mean.

I can't recall just how many times I've already said it in this thread, but here I go again: Grounded's point of view is not "different" to me, in the sense of being "new". I was required to study it in all its gory details, and I know exactly why it can't be right. Readers who are interested in learning about real physics will make the effort to learn why it can't be right.

edit: typo

geistkiesel

Jun18-04, 08:18 PM

I can't recall just how many times I've already said it in this thread, but here I go again: Grounded's point of view is not "different" to me, in the sense of being "new". I was required to study it in all its gory details, and I know exactly why it can't be right. Readers who are interested in learning about real physics will make the effort to learn why it can't be right.

edit: typo
Are there any conditions where the moving frame photons are emitted before the photons in the rest frame? Can A(t') in the moving frame < A(t) in the stationary frame when the times are correlated?

Tom Mattson

Jun18-04, 08:24 PM

Are there any conditions where the moving frame photons are emitted before the photons in the rest frame?

I can answer that only with a precisely defined setup.

Can A(t') in the moving frame < A(t) in the stationary frame when the times are correlated?

What is "A"?

grounded

Jun18-04, 08:37 PM

Tom, where did Maxwell discuss relative measurements of light? I was under the impression that Maxwell only discussed light from an, at rest relative to the source point of view. Wasn't it Einstein who claimed it must be the same for all frames of reference? Didn't Maxwell basically say that since space offers no resistance to light, than no matter how fast the source is traveling, the light would always travel away from the source at the speed of light? Which one of MAXWELL'S equations (please try to keep it in layman terms) describes what we will measure if the light source is traveling towards us?

I still don’t think you understand my point. In order for you to measure a relative effect, you have to take something out of a formula that we know works.

reilly

Jun18-04, 08:45 PM

Using the same oscilloscope to measure light, you will not read a change in wavelength if you include the distance the observer has traveled, just as with the train. Are you saying that an oscilloscope must include the distance traveled by the observer with all of our measurements, except light? You do realize that if the distance traveled by the observer is not included, then ANYTHING you measure will NEVER show a change in relative speed? If we include the distance when measuring light, the need for SR disappears since there is no change in the wavelength. The only way to measure a change in wavelength caused by the observer’s speed, is to ignore the distance the observer has traveled.

RA*******************
Your case would be greatly strengthed if you could give the mathematical formulation of your distance ideas.
**************************
G The wavelength is the distance light has to travel away from the source in order to complete one cycle.

*****************8
RA NO. Wavelenth is the distance between, say, consecutive maxima of a periodic wave. This comes to us from the mathematicians, and has been in vogue for several centuries.

G That length is the same whether you are there, or not. If you increase speed towards the light, you will pass over those lengths at a faster rate. They do not change in length as you increase speed, only the amount of time spent over each wave changes.
If you believe the observers speed does change the wavelength, then why can we only measure it when we ignore the distance the observer has traveled?[/QUOTE]

**************88

RA With my poor grasp of your subtleties. I don't understand your argument.
But standard analysis of light waves indicates the transformation of frequency and wavelength occurs no matter what or where the source is.
The wave function is, typically, the exponential of

i *( lam*x-nu*t)

where lam is the wavelength and nu the frequency, and i is the squareroot of -1. This form is invariant under Lorentz transforms. If x -> x-x0, where x0 is a source coordinate, the invariance still holds. The fact that the (lam,nu) is a four-vector guarantees the standard formulas for frequency and wavelength transformations. This is pretty basic stuff, explained in more detail in most any text on E&M or relativity. If you want to convince the physics community that your notions are true, then you will need to master the conventional arguments, and show exactly where you are right and the rest of us are wrong.

One thing that is often missed by anti-relativists is the fact that the theory of electromagnetic radiation from moving charges, based on the so-called Lienard-Weichart potentials. is quite dependent on the strictures of Special Relativity. This radiation theory works like a charm. This theory, in fact is one of the towering triumphs of Special Relativity, and will not fall easily.

If you can do the math, and explain the phenomena critical to your arguments, preferably by experiment, your chances for a Nobel Prize are excellent.

Regards,
Reilly Atkinson

reilly

Jun18-04, 08:55 PM

I'm replying to a post of Grounded done early in this thread. RA

grounded

Jun18-04, 08:58 PM

Your case would be greatly strengthed if you could give the mathematical formulation of your distance ideas.

Did you happen to read post #52?

russ_watters

Jun18-04, 10:17 PM

Wasn't it Einstein who claimed it [C] must be the same for all frames of reference? Einstein didn't "claim" it, he used the already known fact as the first postulate in his new theory. Big, big difference.

I like Tom's way of listing your predjudices here. I think this one (#1) is the most serious: That the speed of light is constant is not simply some arbitrary assumption made for for convenience in the math of SR. It is high precision experimental fact and you need to accept that.I still don’t think you understand my point. In order for you to measure a relative effect, you have to take something out of a formula that we know works. Take what out of what formula?

wespe

Jun19-04, 12:07 AM

Did you happen to read post #52?

Have you read #53?

Let me try again:

"The distance the passing car travels in one second". This is speed.

"The amount of time it takes ONE car to fully pass you". This is 1/frequency.

So, you are calculating the wavelength by dividing speed by frequency.

OK. Here is your mistake:

This is what happens when you DO NOT include your distance traveled:

(Only the distance the passing car travels in one second) (80.66 Feet)(This is a known value)

What is this "known value" of 80.66? It is in fact the speed of the car wrt the road. The answer comes out wrong because of dividing the speed wrt the road by the frequency wrt the observer. You can't mix measurements made wrt different frames. And nobody is making such a mistake as you imagine.

To calculate the wavelength of light:
1- Measure the speed of light wrt yourself.
2- Measure the frequency of light wrt yourself.
3- Divide the speed by frequency.

Please note that at step #1, we don't just use a speed measurement made in some other frame (as "known value"), we really measure it wrt ourself. Therefore the mistake you imagine is not being made.

But, the value we measure wrt ourselves turns out to be the same value measured made in any other frame, c. So, no, we aren't neglecting the extra speed or traveled distance, it is light itself doing this.

And to make it really clear:

You don't have to assume speed of light constant wrt all frames. You just measure it in those frames. It just turns out to be always equal to c. Back to your car example, it would be funny if you measured the relative speed of the car to be constant. But this is the case with light. This is experimentally supported.

Tom Mattson

Jun19-04, 02:58 AM

Tom, where did Maxwell discuss relative measurements of light? I was under the impression that Maxwell only discussed light from an, at rest relative to the source point of view.

To tell you the truth, I don't know what Maxwell thought about light propagation under coordinate transformations. It really doesn't matter (except perhaps for historical interest) because today we have better information than he ever could have had.

Wasn't it Einstein who claimed it must be the same for all frames of reference?

Yes, he was the first to claim that. And since then, it has been confirmed by experiment.

Didn't Maxwell basically say that since space offers no resistance to light, than no matter how fast the source is traveling, the light would always travel away from the source at the speed of light? Which one of MAXWELL'S equations (please try to keep it in layman terms) describes what we will measure if the light source is traveling towards us?

I've already explained this. Will you please try to pay attention?

It isn't any one of Maxwell's equations that tells us that the speed of light is independent of the speed of the emitter. It is the requirement of the invariance of all of them that leads to the prediction.

I still don’t think you understand my point.

Look in the mirror.

I understand your point perfectly. It's just that you are wrong. Try to get over your ego and see that.

In order for you to measure a relative effect, you have to take something out of a formula that we know works.

And pray tell, what formula is that?

svitenti

Jun19-04, 04:42 AM

Every time i enter this part of the forum i laugh a lot, but this time there is something i cannot understand, why Tom Mattson and russ_watters are still trying to convince these insane people about things already founded 100 years ago. IF SR is wrong, the error will be only aparent near some cut off like plank lenght. You see, all those equations like dirac's and klein gordon and others, come just from representations of poincare group, so if you don't like SR you have to give us other group so we get the equations and test it against the experiment, hum... i talked too much

ram1024

Jun19-04, 04:51 AM

you'll get to laugh soon, because special relativity falls this weekend.

it will be hysterical to set science back a 100 years. we'll all have a good chuckle i'm sure

geistkiesel

Jun19-04, 06:07 AM

Some observations on the corfrectness of information exchange re om_Mattson v Grounded.
Grounded, we all understand it. That's because we all studied nonrelativistic physics before learning SR. It's just that you aren't understanding what we are saying. Let me explain.

What Russ and I have been telling you, and what you aren't understanding, is this:

The wavelength of the light in the rest frame of the source is not special. There's no reason to think that it is the "correct" wavelength, while all others are only "apparent". There's no reason whatsoever to use any correction for the distance the observer has traveled, and I'll explain why later on.

It does make sense to use SR to prove you wrong, because you yourself deduced from your hypothesis that the speed of light is not the same in every frame. And indeed, if your hypothesis is true, your deduction would be true also.

Grounded is saying that current system (SR) for measurement of wave length is flawed by not taking ino account the motion of the observer. A counter argument using SR is, therefore, pecipitous, premature at this point in the exchange. You repeatedly claim Grounded doesn'yt understand what you are etelling him, which isn't a scientific arguement, or reasoning.

But the deduction is not true: The speed of light is the same in every frame.

I don't think you are seeing exactly how SR connects to your argument.

But the theory was not developed to account for wavelength measurements. The theory was developed for the exact reason I said it was developed: To maintain the invariance of the equations of electrodynamics when transforming from one inertial frame to another.

Same basic observation. You try to submerge Grounded before you have understood his complete argument. Your intervention as he goes along voids your responses as having scientifically value. All your history rationale etc do not go to Grounded's thesis. I cannot understand why you have been unable to see what G is saying. Your misunderstanding is manifest with premature interjection of SR arguments, prior to the defined completion of the developing thread.

This not a minor point, none are. If you look closely Tom you will see Grounded does not assume SR is wrong befoe he starts, but you assume SR is correct and from this you make the assumption that Grounded has started with an asumed contradictiion with SR..

How many times do you have to observe that your intense application of SR themes does not attractg all the curious scientists, nor is it convincing?

You said you came here to talk to professionals about this, yes? Please take the advice of this professional: You are never going to get out of these circles you are stuck running around in until you understand the problem above.

No problem on my end. The question is, will you do the same?

Understanding it is no problem. Your points are nothing new to me: physicists have to study nonrelativistic physics before learning SR. It's not that I don't understand you, it's that I understand that you are wrong.

Tom look at this exchange and point to scientific worth. Grounded understands you, but he didn't approach you as a "professional" to hear you echo SRT. He wanted a critique of his system and he wanted the criitique fully void of attempted refutations and corrections such as "Because SR says so [etc].

You are trying to obtain a surrender . The "circles" are your ["standard model"] insertions into this thread, not Grounded. At no instant have you made an attempt to analyze a completed "model" by Grounded ,in his tems. Try hard to see your approach to solutions to these situaitions is problematics

And now we come to Prejudice #1, that you must abandon if this is to make any progress. When you say that the speed of light is not the same to all observers, the logical implication is that Galilean relativity is correct and Special relativity is wrong. That is why I attempted to explain to you why this cannot be so. You can't state what you state on the one hand, and then refuse to listen to why it's wrong on the other, and expect this discussion to get anywhere.

I wish you were more interested in learning physics, because you would know that you would not be ridiculed for saying this. Do you know why?

I know the "why" answer. From the example here :the illogical insertion of counter arguments before a structure is dynamically defined is sufficient to negate the worth of the counter point at tha position in the new theory.

Because I used the exact same approach in my post on Maxwell's equations.

I started with classical EM theory, and I assumed that SR was wrong, and I derived a prediction that is contrary to what we observe.

OK

OK again.

Not OK.

You are wrong when you say that this is the "only way", and I know that I have explained it more than once in this thread. Please do what you ask of the rest of us and listen to our responses.

Again, with emphasis: There is no reason whatsoever to state that the observer has traveled any distance. Your statement reflects Prejudice #2, which you also must abandon: There is no way to even define absolute motion. We are not forced to say that the obserer is moving 10 MPH. We are perfectly free to say that the observer is at rest, and that the car under observation is moving towards him at 65 MPH (notice that I'm not taking SR into account). All the observer has to do is take the 65 MPH, multiply by the time required to pass, and we get the correct length.

when a SRT makes a claim that a train can make the assumption that the platifrm is moving and the train is motionless may have an appetizing appeal for SRT, but it is unambiguously more than irrational, especially when we see that the passengers on the train are seen as the ones reacting to acceleration, the motion involved frame.. SR says the acceleration is of no consequence to SR under the conditions just described, that the train, the frame the people, the seats and weels and coffe tables are not in a higher energy state than the obsjects on the platform. You can use your theory all day long, but when you get to the "we can look from the train frame of the stationary frame equivalently, that I drop out of the conversation, becuse any assumption that ignores the accelertation, at the very minimum, is incomplete.

What seems so beautiful to your math mind make my mind reject and I ain't changing until the model is presented in a full rational mode.

All you have to do is use the relative velocity, and the time required for the car to pass, and you get the correct car length.

That is exactly what we do when we make measurements.

Yes. But unlike you, I also notice the differences. This brings us to Prejudice #3, which you also must abandon if you are to see your way out of this error. Specifically, you are prejudiced towards the opinion that a stream of light pulses can be treated in the same way as a stream of cars. It can't!.

You are correct in saying that an observer errs in making a measurement of the length of the car using its ground speed of 55 MPH when the observer's own ground speed is 10 MPH in the other direction. The reason you are correct is that there is (according to pre-relativity) a relative velocity of 65 MPH between the two cars, and that is what must be used to get a correct result.

But what happens when we look at light? The relative speed never changes, no matter what the speed of the source. The relative velocity between a light pulse and any observer is c. And since the speed of light is the same for everyone, no frame has any special claim to knowledge of the "correct" wavelength of any light pulse. All measurements are equally valid for their respective frames.

Your entire case rests on a rejection of that fact, and that is why you are wrong.

edit: typo
Same basic flaws.

I f you looked at light like Grounded suggests you don't get the same answer as SR, as you measue somthing other than you would if you were doing some SR experiment.

try to see the problem. not from the eyes of an attorney who is trained to scrutinize through an adersarry process. Science is an objective , empathetic process, where Tom, there aren't any winners. Even if, EVEN IF, SR were to suffer a manifest blow, even a fatal one, so what?

It appears that your collective scientific position is the injection of SR theory for all problems. Tom, this is my observation, my perception.

You aren't seeing the pocess here as a practical model.

You should be as helpful as possible in assisting Grounded in every conceivable angle in developing his thread and model. You aren't meeting his stated request. He was looking for assistance, and you demand he learn SR, when he wants to lern his ownm model, which he wants to develop in the theory development forum..

grounded

Jun19-04, 08:53 AM

OK Tom... lets say we do an experiment with some known values.

The distance light travels away from the source in one second = 186,000 miles
The distance the observer travels towards the source in one second = 4,000 miles
The wavelength of the light while at rest relative to the source = 1 mile
The above are known because we set up the experiment.

The relative frequency of the light measured by the observer while in motion = 190,000 cycle per second

The relative distance traveled in one second, divided by the relative frequency, equals the relative wavelength, right?

So (186,000 + 4,000) divided by 190,000 equals the wavelength (1 mile) Agree?

The part of the formula that you throw out is “the distance the observer has traveled relative to the source”.
You throw it out by not including it into the scale of the equipment used to measure the speed or wavelength, which is why you will always measure the total relative distance traveled by the light and the observer to be 186,000 miles.
I agree that you are not consciously throwing this out; you just never realized it was missing.

If you do not include the 4,000 miles the observer has traveled you will measure the following:
THIS NUMBER IS CAUSED BY INCORRECT MATH; IT IS NOT CAUSED BY SR.
(186,000 + 0) divided by 190,000 = .9789 miles

Is not that the wavelength you predict the observer will measure due to SR?

If you tell me that you are dividing the frequency into 186,000 miles because that is what you measured, then I’m telling you that you are measuring it wrong. Since we set up the experiment, we know the observer is traveling towards the source at 4,000 miles per second. We also know that light will travel away from the source at 186,000 miles per second. We do not really even have to measure these values. We know the total relative distance traveled is 190,000 miles per second.

The observer knows he is traveling towards the light source at 4,000 miles per second.
The observer knows the light will travel 186,000 miles away from the source in one second.
The observer knows the relative distance traveled is 190,000 miles per second, this is a fact.

If and when the observer measured the total relative distance traveled in one second to only be 186,000 miles, he was smart enough to know that he has some how measured it incorrectly. He knows this for a fact because he knows the distance he was from the source when he started the experiment, and he knows the distance he is from the source when he completed the experiment. Again, he knows this because we set up the experiment. He also knows the light is traveling 186,000 miles per second away from the source. Knowing all that for a fact, he KNOWS the total relative distance traveled must equal 190,000 miles per second regardless of what he measured.

When the observer takes the total relative distance traveled in one second (190,000 miles) and divides it by the total relative frequency (190,000 cycles per second) he will get the relative wavelength (1 mile), which is the same length he measured before the experiment while at rest relative to the source.

You claim the observer will measure a change in wavelength due to SR.
Your proof is that we do.
My claim is that you and everyone else has measured the total relative distance traveled incorrectly by not including the distance the observer has traveled. After all, isn’t the total relative distance equal to the sum of the distance light has traveled relative to the source, added to the distance the observer has traveled relative to the source?

If you measure a ray of light with an oscilloscope while in motion relative to the source, where is the distance you have traveled relative to the source? How do you account for it? You don’t, and that is why you will never measure a change in speed.

Your measured change in the wavelength (.0211 miles) will be equal to the distance the observer has traveled (4,000 miles) divided by the measured frequency (190,000 cycle per second). This works BECAUSE the measured change in wavelength is caused by ignoring the distance the observer has traveled.

There is no change in the measured wavelength when you account for the distance the observer has traveled.

If SR exists, then it should be measurable after we include the distance the observer has traveled relative to the source.

grounded

Jun19-04, 09:24 AM

The answer comes out wrong because of dividing the speed wrt the road by the frequency wrt the observer. You can't mix measurements made wrt different frames.

EXACTLY

The frequency wrt the observer equals the number of cycles that pass by you due to the velocity of the light, added to the number of cycles passed caused by your speed towards the source.

The total distance traveled per second (speed) wrt the observer equals the distance light has traveled relative to the source, added to the distance the observer has traveled relative to the source

geistkiesel

Jun19-04, 09:25 AM

But we can see that he isn't transcending anything. He is making choices that lead to the physics of the 19th century, and we know that those choices are wrong.

You forgot the disclaimer "choices are wrong wrt SR" (asming SR "right"

swansont

Jun19-04, 09:29 AM

The relative frequency of the light measured by the observer while in motion = 190,000 cycle per second

The relative distance traveled in one second, divided by the relative frequency, equals the relative wavelength, right?

So (186,000 + 4,000) divided by 190,000 equals the wavelength (1 mile) Agree?

No. Tell me how this doesn't imply that I am measuring the light to be moving at 190,000 miles/s

The part of the formula that you throw out is “the distance the observer has traveled relative to the source”.

...
THIS NUMBER IS CAUSED BY INCORRECT MATH; IT IS NOT CAUSED BY SR.

If you shine laser light of the right wavelength on an atom, it will absorb that light. If the atom starts moving, that absorption slows and stops as the light moves out of resonance - the color has changed. How is the atom "ignoring" the amount that it has moved? It isn't doing any math, AFAIK.

grounded

Jun19-04, 09:48 AM

No. Tell me how this doesn't imply that I am measuring the light to be moving at 190,000 miles/s

That is exactly what I am saying.

If you shine laser light of the right wavelength on an atom, it will absorb that light. If the atom starts moving, that absorption slows and stops as the light moves out of resonance - the color has changed. How is the atom "ignoring" the amount that it has moved? It isn't doing any math, AFAIK.

I don't think the atom cares about the length of the wave, it only cares about the amount of time it takes to complete one wave.

wespe

Jun19-04, 11:54 AM

EXACTLY

But nobody is making this mistake, only you imagine so!!!

By MEASURING the relative speed of light wrt ourself, we already account for the traveled distance.

Clasically, when approaching a light source with v, the value we measure should have been c+v. But experiments reveal it is really c.

You want to make it c+v again by adding v to the MEASURED RELATIVE speed c. Therefore you want to account for the traveled distance TWICE.

Tom Mattson

Jun19-04, 12:52 PM

The distance light travels away from the source in one second = 186,000 miles
The distance the observer travels towards the source in one second = 4,000 miles
The wavelength of the light while at rest relative to the source = 1 mile
The above are known because we set up the experiment.

OK

The relative frequency of the light measured by the observer while in motion = 190,000 cycle per second

It is if you use the pre-SR Doppler formula.

The relative distance traveled in one second, divided by the relative frequency, equals the relative wavelength, right?

So (186,000 + 4,000) divided by 190,000 equals the wavelength (1 mile) Agree?

Right here is where you are directly contradicting both the experimental evidence, and SR. Please try to understand why.

According to pre SR theory, the wavelength will be 1 mile. That is because the speed that the light approaches the observer is 186,000 mps+4000 mps=190,000 mps. So, according to the observer, the wavelength is:

λ=(relative speed of light)/(relative frequency)=(190,000 mps)/(190,000 Hz)=1mile

But we now know that that is false. The Galilean velocity addition formula simply does not hold! Yet you keep happily applying it as though it does, and that’s why you go wrong.

Also, You don’t have to use the “relative distance traveled”. It’s the relative speed that counts. Your numbers for the relative distance and the relative speed happen to have the same magnitude because you are considering the motion over a time of 1 second. But the observer could have moved twice that distance in twice the time, and the above analysis would still give the same result.

What you should take away from this part:

1.Forget about relative distance traveled, and start thinking about relative speed.
2. You can’t simply add velocities like you have been doing.

The part of the formula that you throw out is “the distance the observer has traveled relative to the source”.
You throw it out by not including it into the scale of the equipment used to measure the speed or wavelength, which is why you will always measure the total relative distance traveled by the light and the observer to be 186,000 miles.
I agree that you are not consciously throwing this out; you just never realized it was missing.

I’m not throwing it out at all, because I don’t even work in terms of relative distances. As I keep telling you, relative distance is irrelevant to this analysis. What I do throw out is the increase in relative velocity between the detector and the light.

If you do not include the 4,000 miles the observer has traveled you will measure the following:
THIS NUMBER IS CAUSED BY INCORRECT MATH; IT IS NOT CAUSED BY SR.

No, you are mistaken. The discrepancy is due to the feature of SR that says that the relative speed between light and an observer is always the same.

(186,000 + 0) divided by 190,000 = .9789 miles

Is not that the wavelength you predict the observer will measure due to SR?

No, it isn’t. You are using the classical Doppler formula. When SR came along, the Doppler formula had to be rederived, and it is :

f=f0((1+β)/(1-β))1/2

when the source and detector are approaching.

If you tell me that you are dividing the frequency into 186,000 miles because that is what you measured, then I’m telling you that you are measuring it wrong.

I know what you are telling me. You are mistaken.

Since we set up the experiment, we know the observer is traveling towards the source at 4,000 miles per second. We also know that light will travel away from the source at 186,000 miles per second. We do not really even have to measure these values. We know the total relative distance traveled is 190,000 miles per second.

You have to be careful here, especially about the part in blue. First, relative distance is not measured in miles per second, it is measured in miles. What you mean is that the relative speed is 190,000 miles per second. And second, you are wrong about that: it is 186,000 miles per second. You will only get your result if you assume that SR is wrong, and that the Galilean velocity addition holds. It doesn’t.

The observer knows he is traveling towards the light source at 4,000 miles per second.
The observer knows the light will travel 186,000 miles away from the source in one second.

OK so far.

The observer knows the relative distance traveled is 190,000 miles per second, this is a fact.

No, it is a falsehood.

The rest of your post just seems to be more of the same, so I’m not going to continue. Grounded, please open your mind to the possibility that you are wrong. You say that you want us to listen to you , and I am. But you aren’t returning the favor.

edit: fixed quote bracket

grounded

Jun19-04, 12:54 PM

By MEASURING the relative speed of light wrt ourself, we already account for the traveled distance.

Where? Can you tell me where the oscilloscope, or the interferometer, or what ever you used to measure the speed accounted for the distance traveled relative to the source?

Tom Mattson

Jun19-04, 01:09 PM

Where? Can you tell me where the oscilloscope, or the interferometer, or what ever you used to measure the speed accounted for the distance traveled relative to the source?

The distance traveled relative to the source is irrelevant. What you are talking about is the relative speed (edit: between the source and the observer), but that is also irrelevant. When measuring the speed of light, all you need to do is measure the spacetime coordinates of absorption and emission.

Tom Mattson

Jun19-04, 01:12 PM

Some observations on the corfrectness of information exchange re om_Mattson v Grounded.

It must be awfully hard to make any observations at all, with your head shoved so far up your hind end.

This post of yours contains such asinine misrepresentations of both SR and myself, that I find them unworthy of any detailed response.

You said:

You can use your theory all day long, but when you get to the "we can look from the train frame of the stationary frame equivalently, that I drop out of the conversation

I wish you would. Either that, or get your brain in gear, because you aren't helping, and you certainly aren't here to learn anything.

svitenti

Jun19-04, 01:13 PM

I'm anxious to see what could replace SR, but you known that all the dependent theories of it like QED, QCD, Eletroweak, GR, would fall, but remember that these theories give good results, and like i said one replacement to SR has to give THE SAME results to the energy used today.

wespe

Jun19-04, 01:21 PM

Where? Can you tell me where the oscilloscope, or the interferometer, or what ever you used to measure the speed accounted for the distance traveled relative to the source?

What do you think relative speed is?

Consider please:

You are in a spaceship x meters long. There are windows on the front and back. Someone far away sends a light signal. You let the signal pass through your windows. You take note of the times when light enters the front window and exits from the back window. So you can calculate deltaTime. Now you can calculate speed of light as x/deltaTime. You find it to be 300.000 km/sec. That is the relative speed of light wrt you. Because all of them were your measurements. You don't care about the distances anyone traveled wrt something else, you just measure how long it took for light to pass the distance on your ship. So you measured the relative speed of light wrt you.

Now, you fire your thrusters, and start approaching the light source. You repeat the experiment. Oddly, you find the same relative speed of 300.000 km/sec! Light doesn't seem to care how fast you are approaching it!

Suppose, you wanted to measure the relative speed of a rock, instead of light. Same procedure. But, after you fire the thrusters, you find the relative speed of rock increased. For light, it does not increase, experimentally shown. Please do a google search how light speed was measured.

wespe

Jun19-04, 02:14 PM

Where? Can you tell me where the oscilloscope, or the interferometer, or what ever you used to measure the speed accounted for the distance traveled relative to the source?

I guess you didn't like my answer above.

OK I try again: the distances traveled are accounted by the moving objects themselves, when relative speed is measured. Because, relative speed is the approach speed, if you will understand that term better. Approach speed is directly measured by the observer. If you try to calculate it by adding or subtracting speeds of the objects wrt something else, then the answer you get will not match the directly measured speed. This mismatch becomes more and more as the speeds approach c. And relativity describes why this mismatch occurs, and how to do it correctly. Is there anything not clear?

grounded

Jun19-04, 02:17 PM

What do you think relative speed is?

Consider please:
You are in a spaceship x meters long. There are windows on the front and back. Someone far away sends a light signal. You let the signal pass through your windows. You take note of the times when light enters the front window and exits from the back window. So you can calculate deltaTime. Now you can calculate speed of light as x/deltaTime. You find it to be 300.000 km/sec. That is the relative speed of light wrt you. Because all of them were your measurements. You don't care about the distances anyone traveled wrt something else, you just measure how long it took for light to pass the distance on your ship. So you measured the relative speed of light wrt you.

This is a theoretical experiments created off SR, but if it was done it would agree with what I am saying. Currently we calculate the relative speed of light from measurements of the frequency or the wavelength, but we always divide them into 186,000 miles.

Relative speed is the sum of the distance traveled by both objects in one second.

The relative speed between car “A” and car “B” is equal to the sum of the distance car “A” has traveled in one second, added to the distance car “B” has traveled in one second.

60 miles in one second, added to 40 miles in one second, equals a relative speed of 100 miles per second.

How do you define relative speed?

People say we can’t measure the speed of light like this because of SR. Fine.

If that is so, we should be able to measure the speed of light, as done above, and clearly see the effect of SR. But we won’t.

We currently do not include the distance traveled by the observer (speed) when we calculate the relative speed (total relative distance traveled per second), which guarantees a constant speed of light, no matter what.

Don’t you think it’s odd that we have to change the formula in order to measure SR effect?
By change I mean, replace “relative speed” with “speed of light” as shown below.

SPEED OF LIGHT divided by RELATIVE FREQUENCY equals RELATIVE WAVELENGTH

Instead of:

RELATIVE SPEED OF LIGHT divided by RELATIVE FREQUENCY equals RELATIVE WAVELENGTH

If SR is valid, why can't we measure its effect using normal means.

grounded

Jun19-04, 02:22 PM

the distances traveled are accounted by the moving objects themselves, when relative speed is measured. Because, relative speed is the approach speed, if you will understand that term better. Approach speed is directly measured by the observer. If you try to calculate it by adding or subtracting speeds of the objects wrt something else, then the answer you get will not match the directly measured speed.

Can you put this in a car "A" and car "B" perspective with math and show how the distance car "B" travels is accounted for?

wespe

Jun19-04, 02:27 PM

Currently we calculate the relative speed of light from measurements of the frequency or the wavelength, but we always divide them into 186,000 miles.

Where did you get that idea? Relative speed is measured directly, similar to what I described. By letting light pass a known distance, and dividing the distance by the time it took light to pass it (of course, assuming speed of light does not vary while it passes the distance). There is an issue with one-way / two-way measurements, but you first have to understand these before you get to that point.

Google search "how is the speed of light measured"
http://216.239.41.104/search?q=%22how+is+the+speed+of+light+measured%22&ie=UTF-8&hl=en

Tom Mattson

Jun19-04, 02:34 PM

This is a theoretical experiments created off SR, but if it was done it would agree with what I am saying.

No, it wouldn't.

Currently we calculate the relative speed of light from measurements of the frequency or the wavelength, but we always divide them into 186,000 miles.

No, that is wrong. We can measure the speed of light just by knowing the times and places of emission and detection in our frame of reference. There is no need whatsoever to do speed of light measurements using either wavelength or frequency.

Relative speed is the sum of the distance traveled by both objects in one second.

The relative speed between car “A” and car “B” is equal to the sum of the distance car “A” has traveled in one second, added to the distance car “B” has traveled in one second.

"Distance traveled" according to whom? You keep ignoring the fact that I am not obliged to regard the observer as moving at all. I can consider him to be at rest if I want.

But in any case, the relative speed of a light pulse is simply its change in position divided by the time it took to cover the distance. It will come out the same no matter if I regard the observer as moving or stationary. This is true either in Galilean relativity, or in SR.

60 miles in one second, added to 40 miles in one second, equals a relative speed of 100 miles per second.

That is the Galilean velocity addition formula again. It doesn't apply in the real world.

How do you define relative speed?

I define it as the rate at which the distance between other objects and myself changes as a function of time.

People say we can’t measure the speed of light like this because of SR. Fine.

Nobody says that. We say that when we do measure it, it confirms SR and contradicts what you are saying.

If that is so, we should be able to measure the speed of light, as done above, and clearly see the effect of SR. But we won’t.

Of course we will. In fact, we have. The speed of light has been measured to be 'c', even from very fast moving sources.

We currently do not include the distance traveled by the observer (speed) when we calculate the relative speed (total relative distance traveled per second), which guarantees a constant speed of light, no matter what.

Right. We calculate it that way because it agrees with measurements.

Don’t you think it’s odd that we have to change the formula in order to measure SR effect?

Will you please try to open up and learn some actual physics? The whole point of my post on Maxwell's equations was to explain why it's not odd.

By change I mean, replace “relative speed” with “speed of light” as shown below.

SPEED OF LIGHT divided by RELATIVE FREQUENCY equals RELATIVE WAVELENGTH

Instead of:

RELATIVE SPEED OF LIGHT divided by RELATIVE FREQUENCY equals RELATIVE WAVELENGTH

We do that because the relative speed of light is the same for everyone.

If SR is valid, why can't we measure its effect using normal means.

This is a bogus question. SR is valid, we do make measurements with normal means, and the effect is observed.

wespe

Jun19-04, 02:36 PM

Can you put this in a car "A" and car "B" perspective with math and show how the distance car "B" travels is accounted for?

But the correct math will have to be SR math. If you do it as Galilean, the answers will be different, but wrong. Wrong because experiments don't agree with it. So, math doesn't prove anything, only experiments can decide. But if you are just asking to see the SR math, I guess I can do it (if you give me some time, I'm a bit slow, or there are people here who can show it quickly, I'd appreciate their help)

Edit: With Galilean math, the traveled distance is still accounted for. When working with slow speeds, the answers are approximately correct. So if you want that, I can show it quicker. Please let me know.

Tom Mattson

Jun19-04, 02:47 PM

Can you put this in a car "A" and car "B" perspective with math and show how the distance car "B" travels is accounted for?

Whether you are using Galilean relativity or SR, the equation is the same.

I can calculate the relative velocity between and a light pulse and myself by measuring the following:

Event 1: Pulse Emitted
x1=Location of emitter on x-axis at time t1.
t1=Time of emission.

Event 2: Pulse Detected
x2=Location of detector on x-axis at time t2.
t2=Time of detection.

The speed of the pulse relative to me is then:

v=(x2-x1)/(t2-t1).

For light, this will always come out to be c. And as you can see, that result is not "built in" to the way we calculate relative speed. It is a simple, undeniable experimental fact.

wespe

Jun19-04, 03:01 PM

Whether you are using Galilean relativity or SR, the equation is the same.
Yes. I was thinking of first defining the scene from a third perspective, then transforming for A and B as Galilean. And show that the traveled distance is accounted for, despite approximately correctly for low speeds.

grounded

Jun19-04, 03:14 PM

We currently do not include the distance traveled by the observer (speed) when we calculate the relative speed (total relative distance traveled per second), which guarantees a constant speed of light, no matter what.

Right. We calculate it that way because it agrees with measurements.
That is my whole point...

Whether you are using Galilean relativity or SR, the equation is the same.

v=(x2-x1)/(t2-t1)

The above formula has nothing to do with calculating relative speed. Integrate the formula. All this formula does is calulate the amount of time it takes light to travel from the source to the point it was detected. Your speed has nothing to do with anything in this formula except that it will alter the distance light can travel before you detect it.

Tom Mattson

Jun19-04, 03:21 PM

That is my whole point...

What, that we construct our theories so that they agree with experiment? Guilty as charged!

Now the real question is, Why do you have a problem with that?

The above formula has nothing to do with calculating relative speed.

Wrong. That formula is the very definition of relative speed.

Integrate the formula.

What?

All this formula does is calulate the amount of time it takes light to travel from the source to the point it was detected.

Right. And the ratio of those two quantities is the speed of the light relative to me.

Your speed has nothing to do with anything in this formula except that it will alter the distance light can travel before you detect it.

That's because my speed is zero. I am always free to regard myself at rest if I am not accelerating.

grounded

Jun19-04, 03:45 PM

Right. And the ratio of those two quantities is the speed of the light relative to me.

That formula is the very definition of relative speed.

No it isn't, it is the speed of light relative to the source. Can't you see that? It simply measures the amount of time it takes light to travel a specific distance determined by the location you detect the light.

If you run into the light at a distance of 100,000 miles from the source, what does your speed have to do with anything as long as the experiment ended at 100,000 miles form the source. Think about it... It doesn't matter how fast you are traveling when you end the test, all you are doing is marking a specific distance from the source and measuring how long it took light to get to that spot. If you traveled for two seconds, then no matter what your speed is, you will be 372,000 miles from the source.

Does that make sense?

reilly

Jun19-04, 03:50 PM

Grounded -- Yes, I read #52. You will find your ideas expressed more clearly and succinctly in any freshman physics book -- or high school algebra book(Tom is going to Chicago at 90 mph. Phil is on the same road going the other direction at 59mph. At noon they are 247 miles apart. When do they meet? , going in the correct lanes. Feel free to incorporate the lengths of the cars if you wish. Why not check out the Doppler shifts for radio communication s between the two, and for sound communication -- this is in a world with frictionless planes. In other words, you are discussing Galillean transformations, well known to work in non-relativistic situations. You neglect the experimentally confirmed fact that the speed of light is the same in all inertial frames. given that Maxwell's eq's are invariant under Lorentz transforms(unknown to Maxwell) but not under Galilean transforms requires a very profound change in our notions of time and space and how they are measured. That is to say, your #52 is only true under limited circumstances -- again something known from countless experiments. Svitenti, above, points out that SR is more than messing around with frequencies and wavelengths, and has worked brilliantly for a century.

I ask you again to point out in my argument with a wave function, where i am wrong.
What about radiation theory, Cerenkov radiation, i.e. light going faster than the speed of light in matter, not vacuum, Larmour precession and the magnetic moment of the elctron, and on and on and on? These are all phenomena that require SR to be true (or, better, not false) I'll make you a deal. I taught SR quite a few times. If you can point out the flaws in my argument of a few posts ago, I'll send you my lecture notes so you can have a field day in pointing out my errors.

Just to give you a sense of how extraordinary Einstein's ideas were and are, refer to Bateman's Electrical and Optical Wave-Motion(Dover) written before Einstein's ideas were fully accepted. People did a lot of shucking and jiving over how best to deal with the electromagnetic fields of moving charges. Read some history, if only to see how widespread SR has become -- as I mentioned above, if you can come up with something better than SR, you will have your day in Stockholm.

Regards,
Reilly Atkinson

grounded

Jun19-04, 03:53 PM

Tom

If you divide the distance light has traveled by the amount of time you let it travel, why would you expect to get any answer other than the speed of light?

Tom Mattson

Jun19-04, 03:54 PM

No it isn't, it is the speed of light relative to the source.

Actually, it applies to both. If I use the values of x and t as measured by me in my frame, then it does in fact give me the speed of light relative to me, as I said. But if I use the values of x and t as measured in the frame of the source, then that will be the speed of the light relative to the source.

It simply measures the amount of time it takes light to travel a specific distance determined by the location you detect the light.

Slight correction: It simply measures the amount of time it takes light to travel the distance determined by the location of the detector and the location of the source at the time of emission. It takes two points to determine a distance.

But yes, the formula takes the ratio of that distance and the elapsed time between the two events.

And that ratio is the speed of the light relative to me.

If you run into the light at a distance of 100,000 miles from the source, what does your speed have to do with anything as long as the experiment ended at 100,000 miles form the source.

The distance to the source is irrelevant. Speed is not defined by a distance, it is defined by a change in distance divided by a change in time.

Think about it... It doesn't matter how fast you are traveling when you end the test, all you are doing is marking a specific distance from the source and measuring how long it took light to get to that spot. If you traveled for two seconds, then no matter what your speed is, you will be 372,000 miles from the source.

All I did was take the distance the light covered and divided by the elapsed time. That is the speed of the light in my frame.

Why is that so hard to understand?

Does that make sense?

Not one bit.

edit to add:

I don't want to leave you with the wrong impression. I don't say that your statements make no sense because they are unintelligible, or because I don't understand you. I say it because they make no sense in the framework of what we know to be true about the world.

Your posts are perfectly understandable. They just don't describe the real universe.

Tom Mattson

Jun19-04, 03:58 PM

Tom

If you divide the distance light has traveled by the amount of time you let it travel, why would you expect to get any answer other than the speed of light?

For Pete's sake, just look at the formula. It is not devised to always return "c", regardless of the values of the distances and times. Indeed, those distances and times are determined by experiment. If the Galilean velocity addition formula is true, then the relative speed will be calculated (by that very same formula) to be something other than 'c'. But we don't observe that. We observe what SR predicts, as I'm sure you must be aware by now.

grounded

Jun19-04, 04:21 PM

For Pete's sake, just look at the formula. It is not devised to always return "c", regardless of the values of the distances and times. Indeed, those distances and times are determined by experiment. If the Galilean velocity addition formula is true, then the relative speed will be calculated (by that very same formula) to be something other than 'c'. But we don't observe that. We observe what SR predicts, as I'm sure you must be aware by now.

I don't understand how we can get anything but 'c' if all we are doing is measuring the distance between us and the source, and dividing it by the amount of time it took the light to get there.

Being serious, are you saying that because of SR we have to change the times and distances?

Can't we use that formula from a third perspective with no reletivistic effects since the location of the source, the locations of the spot the test ended, and the time it took the light to get there the same for the observer or someone on the source?

grounded

Jun19-04, 04:41 PM

All I did was take the distance the light covered and divided by the elapsed time. That is the speed of the light in my frame. Why is that so hard to understand?

All the formula says is that light travels from the source at the speed of light. So in one second the ray of light will be 186,000 miles from the source and the observers speed cannot change this.

grounded

Jun19-04, 04:51 PM

If you run into the light at a distance of 100,000 miles from the source, what does your speed have to do with anything as long as the experiment ended at 100,000 miles form the source.

The distance to the source is irrelevant.

How can you say that since the only distance we are measuring is the distance to the source? In fact the only thing we are measuring is the distance from the front of your spaceship to the source, and dividing it by the time it took to get there.

Tom Mattson

Jun19-04, 04:57 PM

I don't understand how we can get anything but 'c' if all we are doing is measuring the distance between us and the source, and dividing it by the amount of time it took the light to get there.

What's not to understand? The formula contains independent variables. It's not as though they cooperate to trick us by always working out to be 'c'.

Being serious, are you saying that because of SR we have to change the times and distances?

Yes, the times and distances do change, but it is not "because of SR", it is "because that's the way the universe works". The absoluteness of the speed of light gives rise to the phenomena of time dliation and length contraction. Moving clocks tick slower relative to your frame, and moving yardsticks are shorter in your frame.

Can't we use that formula from a third perspective with no reletivistic effects since the location of the source, the locations of the spot the test ended, and the time it took the light to get there the same for the observer or someone on the source?

There are no relativistic effects in the formula for relative speed. The relativistic effects don't show up until you do precisely what you hint at here: Consider a third point of view. But we can't add that third perspective without way to transform coordinates between frames. So let's do that, using both Galilean relativity and Special Relativity.

Let a light source S be moving towards observer O at v=0.5c. Let S emit a pulse. Furthermore, let observer O' be at rest with respect to the source. This implies that the speed of light u' relative to him is c.

Again, let Event 1 be the emission of the pulse, and let Event 2 be the detection.

Question: What is the speed of light u as measured by O?

Here are two different answers, one from Galileo and one from Einstein.

1. In Galilean relativity, the transformation between spacetime coordinates (x,t) that O assigns to events, and those coordinates that (x',t') that O' assigns to events, are related by the following transformation:

x'=x-vt
t'=t

If we take the difference in distance Δx and Δ'x;', as measured by each observer, and similarly take the differences in time Δt and Δt', then each can compute the velocity of light relative to himself:

Δx'/Δt'=Δx/Δt-v.

Since Δx'/Δt'=u' and Δx/Δt=u, we have

u'=u-v

This is the Galilean velocity addition formula, which you are so fond of. Recall that u'=c and v=0.5c. Inserting them into the formula, we come up with a prediction of u=1.5c.

That is, Galilean relativity predicts that x2, x1, t2, and t1 will all be measured in such a way that the ratio of (x2-x1) to (t2-t1) will be 1.5c.

2. In Special Relativity, the transformation between spacetime coordinates (x,t) that O assigns to events, and those coordinates that (x',t') that O' assigns to events, are related by the following transformation:

x'=γ(x-vt)
t'=γ(t-vx/c2)

where γ=(1-v2/c2)-1/2

If we take the difference in distance Δx and Δ'x;', as measured by each observer, and similarly take the differences in time Δt and Δt', then each can compute the velocity of light relative to himself:

Δx'/Δt'=(Δx-vΔt)/(Δt-vΔx/c2)

Dividing the top and bottom of the right side by Δt, we get:

Δx'/Δt'=(Δx/Δt-v)/(1-v(Δx/Δt)/c2)

Since Δx'/Δt'=u' and Δx/Δt=u, we have

u'=(u-v)/(1-uv/c2)

This is the velocity addition formula in SR. Recall that u'=c and v=0.5c. Inserting them into the formula, and solving for u, we get u=c.

That is, Special Relativity predicts that x2, x1, t2, and t1 will all be measured in such a way that the ratio of (x2-x1) to (t2-t1) will be c.

The only way to find out which is correct is to do the experiment, and collect the information on x1, x2, t2 and t1.

As it happens, SR is correct. The simple velocity addition formula of Galilean relativity does not work.

Tom Mattson

Jun19-04, 04:59 PM

All the formula says is that light travels from the source at the speed of light. So in one second the ray of light will be 186,000 miles from the source and the observers speed cannot change this.

No, you are wrong. The formula doesn't say that at all. The formula contains quantities that are determined by experiment. Given (x2-x1), there is no way to know ahead of time what (t2-t1) is going to be.

Tom Mattson

Jun19-04, 05:02 PM

How can you say that since the only distance we are measuring is the distance to the source? In fact the only thing we are measuring is the distance from the front of your spaceship to the source, and dividing it by the time it took to get there.

I already explained this to you. I say that the distances themselves are irrelevant, because it is only the change in distance that goes into computing the speed.

Look at the formula again:

v=(x2-x1)/(t2-t1)

The values of x2 and x1 (the distances) don't matter. What matters is their difference.

wespe

Jun19-04, 06:21 PM

If you run into the light at a distance of 100,000 miles from the source, what does your speed have to do with anything as long as the experiment ended at 100,000 miles form the source. Think about it... It doesn't matter how fast you are traveling when you end the test, all you are doing is marking a specific distance from the source and measuring how long it took light to get to that spot. If you traveled for two seconds, then no matter what your speed is, you will be 372,000 miles from the source.

Tom Mattson has explained well, but just in case you are still confused..

OK, if distance is 100,000 miles, what value will you divide this by? You have to divide it by (detection time - emission time). How will you know the emission time? You can't measure it directly, because you are in the ship. The distance is also contracted due to SR effects, and it is difficult to see what the ship would directly measure as distance. These are additional complexities. To avoid them, my example did not include light emission time. It included two time values that you measured inside your ship. And the distance was again measured inside the ship. Divide and find the speed, v=dx/dt, should be simple enough.

grounded

Jun19-04, 08:38 PM

Just so you know Tom...I really appreciate the time you have given up to respond to all my posts. Even though we don't agree, you still respond, thanks.

I do however have yet another question.
Given (x2-x1), there is no way to know ahead of time what (t2-t1) is going to be.
If I am given the location of the source (x1), and I am given the location of the detector (x2), isn't (t2-t1) equal to the amount of time it takes to travel (x2-x1) at the speed of light?

Tom Mattson

Jun19-04, 08:52 PM

Just so you know Tom...I really appreciate the time you have given up to respond to all my posts. Even though we don't agree, you still respond, thanks.

I don't mind, because you are obviously sincere.

I do however have yet another question.

If I am given the location of the source (x1), and I am given the location of the detector (x2), isn't (t2-t1) equal to the amount of time it takes to travel (x2-x1) at the speed of light?

It will return the speed of light relative to me. The definition of relative speed--by itself--does not prefer the SR velocity addition formula over the Galilean velocity addition formula. If you go back to my example with the light source moving at 0.5c towards me, where I work out the prediction using both Galileo and Einstein, you'll see that the exact same definition of velocity is used in both cases. If Galileo is correct, then the time elapsed (t2-t1) will be such that the speed of the light in my frame is 1.5c. And if Einstein is correct, then it will be such that the speed is c.

So the experimental question is: When does the pulse arrive?

Hopefully you now see that the result is not guaranteed to be 'c' just by virtue of the definition of relative velocity.

grounded

Jun19-04, 08:58 PM

OK, if distance is 100,000 miles, what value will you divide this by?

When I see this:

v=(x2-x1)/(t2-t1)

I see this:

v=(The distance between the source and the detector) / (The amount of time it takes light to travel from the source to the detector)

From my perspective the observers speed only changes the position of the detector, but we are still only calculating the amount of time it takes light to travel from the source to the detector.

Tom Mattson

Jun19-04, 09:02 PM

When I see this:

v=(x2-x1)/(t2-t1)

I see this:

v=(The distance between the source and the detector) / (The amount of time it takes light to travel from the source to the detector)

The part in red is not quite right. Remember that Event 1 was defined to be the emission of the pulse. That means that x1 is the location of the source when the light was emitted. The source may move after time t1, and so x2-x1 is not the distance between the source and the detector. It is the distance between the emission and the detection.

In other words, it is the distance that the light travels.

wespe

Jun20-04, 12:33 AM

All the formula says is that light travels from the source at the speed of light. So in one second the ray of light will be 186,000 miles from the source and the observers speed cannot change this.

Oh I now see why you are saying this. It's the syndrome: thinking in absolutes. You may be over this by now, but just in case..

You assumed that there is an absolute space (aether) out there, in which things can move. The speed of an object in aether (or wrt aether) can be known. Let's call this speed "absolute speed". Absolute speed of light is somehow known and is equal to c. Then of course you would say that an observer approaching an emitted light won't change light's [absolute] speed.

But, we are not talking about absolute speeds. In fact, there is no way to measure absolute speed, because there is no way to detect absolute motion. Therefore, the existence of aether has been denied. There is no evidence that aether even exists so let's forget about it, along with absolute speed.

So now we can only talk about relative speeds. Consider: when you approach something, it also approaches you with the same speed you approach it, right? That mutual speed is the relative speed. It doesn't matter who is really approaching who, relative speed between two objects has only one single value, unlike two objects having two different absolute speed values.

Still, we can measure two different values, if we consider the relative speeds of two objects wrt a third object. Then, using these two values, we can calculate relative speed of these objects wrt each other. Galilean relativity would simply add the two values as v1+v2, which is intuitive. But when the speeds are high, it turns out that the formula does not hold true.

And the rest is history.. LOL I wrote too much.

I hope this helped.

reilly

Jun20-04, 12:54 AM

Grounded -- Not up to my challenge(#91), I guess.? Still, in preperation, I'm getting my SR lecture notes together. RA

Chronos

Jun20-04, 04:16 AM

this has gotten totally out of hand. unless you are questioning the maxwell equations, you have no point. all einstein did was put it all together in a predictive model. is e=mc^2 a lucky guess, or is it reality? do lorentzian transforms work as a predictive model? how do you explain that future observations fit the math that predicted them? perhaps we do not have a 'perfect' model that explains all that is observed, but, it is a much better model than the kind of unsupported models proposed by quacks such as savov.

why is it such a contradiction to refine the mathematics of reality? the equations do not change without evidence in support of observation. no one is claiming we are infallible [aside from the quacks]. we adjust theory when it is supported and has the mathematical foundations to support observational evidence.

grounded

Jun20-04, 08:35 AM

Grounded -- Not up to my challenge(#91), I guess.? Still, in preperation, I'm getting my SR lecture notes together. RA

I am willing to discuss anything, and want to, but you must realize that you all seem to be at the top of the ladder. You wrote that "I will need to master the conventional arguments", and I agree. My lack of education compared to you, Tom, Qeistkiesel, and others gives me an entirely different perspective, be it right or wrong. I wouldn't come here to waste your time teaching me something I could read in a book. In my opinion I have an extreme grasp on reality and physics. I have read many encyclopedias and books about relativity; I do admit that they are all written in laymen terms such as “Six easy pieces” and “six not so easy pieces” both by Richard P. Feynman. I understand the information I have read and responses people have given (with exception to Tom’s more educated response), but I also have to FULLY understand it in order to accept it.

Some people will call it ignorant, but before I accept something I must fully understand (for myself) why it works. Knowing the motor will start when I turn the key is not enough. I am one of those kids that just had to touch the flame to know it would burn me, knowing it would was not enough. I am not here to push my perspective; I am here more to find that missing piece that would make me understand why my perspective cannot be used, the piece that would make me say “oh, I see now!”. If that still doesn’t make sense then let me ask you this. How much respect would you have for me if I didn’t truly understand any of the information I held? If I conform without understanding, I would just be a walking textbook with a low self-esteem.

Like everyone, I am capable of understanding anything given the proper information. In order for me to understand the conventional arguments, I need to understand what the math is really saying. I have never been able to understand the purpose of using the square root. I mean I know what it does, it gives us a number that when squared equals the number we square rooted. But what does it really do?

For example: (frequency) * (length) = (speed)

This makes sense since if I am diving at 55MPH then I am in a sense driving 55 one-mile lengths per hour. If I drive 60MPH I am driving 60 one-mile lengths per hour.

Can you tell me in words what the square root does, and maybe an analogy?
This is the formula I am referring to.

(square root of –1) *( wavelength*x-frequency*t)

Also can you tell me if in the above formula x = (x2-x1) and if t = (t2-t1) as in the formula below?

v=(x2-x1)/(t2-t1)

wespe

Jun20-04, 10:36 AM

I am willing to discuss anything, and want to, but you must realize that you all seem to be at the top of the ladder.

Grounded, I am no expert and that's why I thought I understood your view better that the experts here, I hope you were not offended by #106.

Can you tell me in words what the square root does, and maybe an analogy?
LOL, if you had a square shaped area, squareroot would convert the area value to the length of the side value (of course I know you know that). So it has something to do with dimension relations I think.

This is the formula I am referring to.
(square root of –1) *( wavelength*x-frequency*t)

I haven't seen that one before. Also there is no = sign so it's not an equation.

Also can you tell me if x = (x2-x1) and if t = (t2-t1) as in the formula below?

well, x is distance, and t is duration

Take care.

grounded

Jun20-04, 10:51 AM

What I was originally looking for was a way to measure light while in motion and get a constant speed using traditional methods.

(LENGTH) * (NUMBER OF LENGTHS PASSED PER SECOND) = (SPEED) = (DISTANCE TRAVELED PER SECOND)

From my perspective (naive or not) SR says we can’t use this method because it will not yield the results of SR, and in order to measure it as constant, I have to measure it in a way that conforms to SR. If the speed of light is constant, shouldn’t I be able to use traditional methods to measure it? I still have not grasped the concept of having to use SR formulas to predict SR effects, which is probably why I have a problem accepting SR’s formulas as proof to SR.

The single concept that has led me to where I am today is this.

Using an interferometer we measure the wavelength of light while at rest relative to the source. If we take the same measurement while traveling towards the source and account for the distance we have traveled, we will not measure a change in the wavelength. Doing it like this we are just counting the number of lengths that pass us and multiplying it by their length. The reason I perceive this to be logical is because of the following.

When the distance between the observer and the source is decreasing, the amount of time it takes the light to complete one cycle will also be decreased, as measured by the observer compared to when the distance between the two are not changing.

An interferometer can be calibrated using a light source with a known wavelength. As long as the distance between the observer and the source are not changing, this will work. Since light travels 186,000 miles per second, the wavelength equals the amount of distance traveled, traveling at 186,000 miles per second, in the amount of time it takes the light to complete one cycle. If the distance between the observer and the source are decreasing, then the wavelength equals the amount of distance traveled, traveling at the sum of “186,000 miles per second” added to “the speed at which the distance between the source and the observer is decreasing”, in the amount of time it takes the light to complete one cycle. If we measure the wavelength in this fashion, we will not measure a change.

I realize this is the old way of calculating and it doesn’t include any of the modern formulas, but it is the only way to make the interferometer measure any ray of light and correctly measure its true wavelength, isn’t that what we want it to do? I know some of you don’t like the term true wavelength, but if I am measuring something I want to measure what it is, not what it perceives to be. I noticed that while in motion relative to the source, the change in distance between the source and observer is not being accounted for. Once accounted for, I realized that using traditional methods, the only way to measure the speed of light to be constant is to ignore the change in distance between the observer and the source.

The above is just so you can see my perspective. As of today, I don’t agree with SR, but even though, I am determined to understand it. Right now I’m going to try to make sense out of Tom’s #98 post.

grounded

Jun20-04, 10:58 AM

I haven't seen that one before. Also there is no = sign so it's not an equation.

It refers to Reilly's post #59

The wave function is, typically, the exponential of

i *( lam*x-nu*t)

where lam is the wavelength and nu the frequency, and i is the squareroot of -1.

Tom Mattson

Jun20-04, 12:43 PM

What I was originally looking for was a way to measure light while in motion and get a constant speed using traditional methods.

But that's just it: We do used traditional methods. The distance traveled divided by the time elapsed is the speed. It doesn't get any more traditional than that. What you aren't accepting is the fact that the "lengths passed" are different for different observers, in a way that has nothing to do with not including the relative motion between source and observer. The lengths are literally phsically contracted in frames other than the rest frame.

As to this:

The wave function is, typically, the exponential of

i *( lam*x-nu*t)

where lam is the wavelength and nu the frequency, and i is the squareroot of -1.

He is referring to the complex exponential function:

f(x)=eikx

It just so happens that this function is sinusoidal, as follows:

eikx=cos(kx)+isin(kx).

In other words, the function is a solution to the wave equation. But instead of using that, you could just use a combination of sines and cosines, that don't include the "i".

Tom Mattson

Jun20-04, 12:54 PM

I realize this is the old way of calculating and it doesn’t include any of the modern formulas, but it is the only way to make the interferometer measure any ray of light and correctly measure its true wavelength, isn’t that what we want it to do? I know some of you don’t like the term true wavelength, but if I am measuring something I want to measure what it is, not what it perceives to be.

As long as you're still hung up on this, you aren't going to see your way through this problem. There simply is no such thing as a "true wavelength". You only believe this to be so, but in reality there is no reason to hold that position. When you make an observation, you simply cannot doctor up the measurment to fit your predisposed vision of reality. As I noted before, I appreciate your sincerity, but your biggest shortcoming as I see it is that your thinking is so rigid. If you are going to understand anything about science, then you have to be prepared to let the experimental evidence dictate your view of the universe. But what you are doing is exactly the opposite: trying to put a skewed interpretation on measured results so that they fit what you already believe. Simply put, that is anti-science, and anti-education, which is why I respond to all of your posts.

As someone who understands this problem inside and out, I can tell you this: You will be forever at odds with physicists on this "true wavelength" thing unless you can understand the more fundamental problem of the invariance of the speed of light. The difference in wavelengths in different frames are derived consequences of that fact. But I'm convinced that you do not yet understand why the speed of light postulate must be true. So in effect what you're doing with this "true wavelength" argument is arguing against a conclusion without understanding the premises used to derive that conclusion.

ram1024

Jun20-04, 01:00 PM

when experimentation does NOT match logical and rational predictions you should look for the faults in your experimentation, not reinvent the universe to match your crazy results...

Tom Mattson

Jun20-04, 01:19 PM

when experimentation does NOT match logical and rational predictions you should look for the faults in your experimentation, not reinvent the universe to match your crazy results...

And this, dear boy, is why you'll never be a scientist.

ram1024

Jun20-04, 01:38 PM

i'm quite open to the possibility that something doesn't work the way i expected it to, but only after i rule out EVERY possible option that conforms to rational and logical approaches

Tom Mattson

Jun20-04, 02:03 PM

i'm quite open to the possibility that something doesn't work the way i expected it to, but only after i rule out EVERY possible option that conforms to rational and logical approaches

Hiding behind a veil of "rationality" does not make your philosophy of science any better. The fact of the matter is that it only takes a single experimental counterexample to prove that a physical theory is false. Distorting the results in the name of logic is intellectually dishonest, and patently unscientific.

As to your prior statement:

when experimentation does NOT match logical and rational predictions you should look for the faults in your experimentation,

This is awfully presumptuous of you, and if I did not already know that it was borne of ignorance I would say that it is awfully arrogant of you.

Your method here requires that a scientist have an innate, a priori knowledge of the way the universe should work, so that he may have a "rational" standard to which he can compare his results. But who has this knowledge? Who is so all-knowing that he can tell what is "rational" apart from experimentation? You? Can you tell us the way the universe should work? Indeed, why do we need to do experimentation at all? I mean, you already know what is "rational", so why can't we just ask you?

not reinvent the universe to match your crazy results...

Your thinking is exaclty backwards. Experimentation is our way of finding out how the universe really is. Twisting experimental results around so that they fit one's predisposed worldview is precisely what it means to reinvent the universe to match one's crazy ideas. I repeat: it is an intellectually dishonest, unscientific practice.

ram1024

Jun20-04, 02:11 PM

The fact of the matter is that it only takes a single experimental counterexample to prove that a physical theory is false.

please do join me in the "Relativity dies today" thread then ;D

This is awfully presumptuous of you, and if I did not already know that it was borne of ignorance I would say that it is awfully arrogant of you.

i'm going to assume my "logic" is absolutely correct until i've exhausted every possible avenue of attack has failed. when challenging a well-known, globally accepted theory or law there is no other way to go about it. to be wishy-washy or half-assed will only lead to failure. it may be arrogant, but it doesn't make it any less "real" when something is disproven with these "tactics"

Your thinking is exaclty backwards. Experimentation is our way of finding out how the universe really is. Twisting experimental results around so that they fit one's predisposed worldview is precisely what it means to reinvent the universe to match one's crazy ideas. I repeat: it is an intellectually dishonest, unscientific practice.

no one's doing any twisting... where are you reading that? :|

Tom Mattson

Jun20-04, 02:24 PM

please do join me in the "Relativity dies today" thread then ;D

The others are kicking your butt just fine without me. ;D

i'm going to assume my "logic" is absolutely correct until i've exhausted every possible avenue of attack has failed.

That's a foolish choice. The only way to determine the truth or falsity of scientific propositions is by observation, not logic.

when challenging a well-known, globally accepted theory or law there is no other way to go about it.

How would you know? What scientific investigations have you ever conducted? (And no, the thread "Today SR Dies" does not count).

to be wishy-washy or half-assed will only lead to failure.

:uhh: I can only assume from the context that "being wishy-washy and half-assed" means "granting epistemic privelige to empirical information over reason in questions of science".

If so, then again, your thinking is exaclty backwards. Rationalism as a scientific method has done nothing but fail miserably, which is why it is dead. The empirical approach, on the other hand, has enjoyed astounding success. Indeed, the lack of a priori knowledge of the universe requires that our investigations be empirically driven.

it may be arrogant, but it doesn't make it any less "real" when something is disproven with these "tactics"

You are so mistaken. There is no way--none whatsoever--to disprove any scientific theory which is internally consistent using only logic. The only "real" way to disprove it is by experimentation.

no one's doing any twisting... where are you reading that? :|

Right here:

when experimentation does NOT match logical and rational predictions you should look for the faults in your experimentation, not reinvent the universe to match your crazy results...

ram1024

Jun20-04, 02:47 PM

"look for faults" does not mean "stage fake experiments to produce the results desired"

having trouble with reading comprehension?

Tom Mattson

Jun20-04, 02:54 PM

"look for faults" does not mean "stage fake experiments to produce the results desired"

Then what do you mean?

having trouble with reading comprehension?

Not at all. If you examine the immediate context in which you posted your comments, you'll see that the inference I made was reasonable. I was discussing the impropriety of a skewed interpretation of experimental results to fit a worldview that one subjectively deems "rational". You jumped in with your comment about looking for faults in the experiment, with no further explanation. I just took your remark in the context of the discussion. It's not my fault if you don't say what you mean.

ram1024

Jun20-04, 03:02 PM

i said exactly what i mean.

something is wrong with your experiments. find out what it is :P

Tom Mattson

Jun20-04, 03:04 PM

i said exactly what i mean.

Might I recommend a bit more exposition then? The quick two-liners simply do not convey the information you wish to convey.

something is wrong with your experiments. find out what it is :P

Here's a perfect example.

On what basis do you say that something is wrong with an experiment, as opposed to something being wrong with a theory?

ram1024

Jun20-04, 03:17 PM

experiments can be re-done and refined, theories are set in stone

The fact of the matter is that it only takes a single experimental counterexample to prove that a physical theory is false.

Tom Mattson

Jun20-04, 03:24 PM

experiments can be re-done and refined,

Correct.

theories are set in stone

That's not a very good way to look at it. If a theory is "set in stone", then it has to be discarded in total when it is falsified. But if you take the point of view that theories can also be re-done and refined (as is the point of view of real scientists, by the way), then by keeping the good and discarding the bad, you don't have to start from scratch every time.

Anyway, you did not even come close to answering my question. :frown:

Here it is again:

On what basis do you say that something is wrong with an experiment, as opposed to something being wrong with a theory?

ram1024

Jun20-04, 03:41 PM

when an experiment using principles proven by OTHER experiments acquires data NOT equivalent to theory. duplicate the experiment a few hundred times under multiple conditions to confirm it's not a fluke. then either that experiment and all other ones supporting it are wrong OR the theory is wrong.

the more times the experiment is tried and scrutinized the MORE correct it is.

Tom Mattson

Jun20-04, 03:44 PM

when an experiment using principles proven by OTHER experiments acquires data NOT equivalent to theory. duplicate the experiment a few hundred times under multiple conditions to confirm it's not a fluke. then either that experiment and all other ones supporting it are wrong OR the theory is wrong.

This I can agree with. Now we just have to get you to see that this very thing has been done many, many times with SR.

ram1024

Jun20-04, 06:44 PM

exactly

this is such fun :biggrin:

reilly

Jun20-04, 11:09 PM

geistkiesel

Jun21-04, 12:47 AM

Grounded -- First, please accept my apologies for being snotty and arrogant(the physicist's disease) I misjudged your zeal and passion for understanding. (Note, however, as my dear Mother told me -- You learn more with your mouth shut than with it open)

Physics is very difficult, for two primary reasons: it requires a real facility with and understanding of a lot of advanced math; the conceptual basis is highly abstract and idealized, in E&M, QM, SR, GR, ....., and is not fully consistent. So, particularly, for the last reason, most physicists are highly pragmatic -- do the best you can with what you have, don't sweat the hard stuff unless it messes up your work. As I'm sure you know, for example, there is huge controversy about the proper interpretation of QM, but many working physicists pay little attention to the controversy. The standard ways work just fine in practice.

Everyone who teaches physics, say SR, will tell you we did not understand SR until we taught it. It takes a long time, and many exposures to SR to get it right. And, most students of SR will tell you that sometimes you have to suspend your judgement to get to a good understanding -- that's the advantage of a good teacher, he/she can suggest what to sweat now, and what to defer. All told, SR is a huge subject, of which the basic space-time kinematics, the x's and t's, comprise only a very small portion. It is the totality of SR that is so compelling.

That being said, the path to a robust understanding of SR necessarily involves lot's of math -- there's no way around that fact.

Tom's explanation of the imaginary exponential is right on. The way, typically, you build up a comfortable intuition about i, the square root of -1, is to work with it, work with it a lot. It's part of the language of physics, and is used so much because it is a powerful tool in working with waves, periodic phenomena, much of QM, and many other branches of physics and engineering.

If you are serious about physics, you need to hit the books, and do the homework. Resnick and Halliday is a good place to start. And, absolutely necessary, learn calculus. Then you will understand that the x and t in the exponential are not x2-x1, t2-t1. That exponential gives you the compex value of the wave amplitude at x at time t.

Once a professor, always a professor.
Regards and good luck

Reilly Atkinson

Really, Reilly, how dare you, but you recovered nicely. perhaps ou can elucidate us on the following:

All moving frame values are non-primed with the exception of M’, the consistent location of the observer O in the moving frame.

At no time is there an inference that M’ was at the midpoint of the A and B photons emitted in the stationary frame.

To demonstrate the following:

Einstein’s moving train calculation indicating when the oncoming B photon is detected at t1 the A photon was located at a position consistent with –t1. Said in other words, as t1 is determined from t0 which locates M’ at t0, the A and B were equidistant to M’(t0) when t = t1.

Proof:
A moving observer located at M’ on a moving frame passes through the midpoint M of photon sources located at A and B in the stationary frame just as A and B emit photons. M’ is moving along a line connecting A and B, toward B.

At this instant the moving source t = t0. Later the moving observer detects the photon from B at t1, and later the photon from A at t2. The observer has measured her velocity wrt the stationary frame as v. Determine the position of the A photon at tx in terms of t0, t1, t2, and v when the B photon was detected at t1.

The photon from A must reach the position of M’ when t = t2. Therefore, the distance traveled by the A photon during Δt = t2 – t1, is Δtc. This is equal to the distance cΔt = vΔt + vt1 + vtx . Now we rearrange somewhat to arrive at, vtx = vΔt – cΔt + –vt1. Now as vΔt - cΔt is just -vtx - vt1

vtx = -vtx - vt1 – vt1

2tx = -2t1

tx = -t1

Therefore, in the moving frame the photon from A and the photon from B were equidistant from M’(t0) at t1.

geistkiesel

Jun21-04, 03:04 PM

But we can see that he isn't transcending anything. He is making choices that lead to the physics of the 19th century, and we know that those choices are wrong.

Tom, excuse me if i've asked this before, but show me Grounded's math in 19th Century physics, AND that 19th century physics is passe because it is so old.

reilly

Jun21-04, 03:29 PM

geistkiesel

Jun21-04, 07:48 PM

geistkiesel -- I really can't figure out what's going on in your scenario. A diagram or two would be very helpful.

But I do suggest you go to any text that discusses basic SR space-time definitions and (idealized) measurements, take pencil and paper and work through, step-by-step, the arguments. Then you will be in a position to answer your own question. If not, you will have far more specific questions to ask about SR. Einstein's book Relativity is elegant and insightful, the more recent Basic Relativity by Richard Mould goes into the basic SR space time structure in enormous detail -- requires only high school algebra at that stage.

Regards,
Reilly Atkinson

Reilly, I truly am grateful for your suggestions but I am a confessed SR heretic, and I am not going to indulge myself in learning something that I am working to get rid of, capice? I do not buy inro the SR story and am especially motivated since Sir Grounded came upon the scene. We should all feel rather grateful that Sir Grounded selected this forum to have his views aired. I do see a lot of denial in respoding posts, do you agree Reilly? Rather than urge Sir Grounded along with suggestions and clues, it seems the SR bushwahackers have come put of theri hiding places and are attempting a full scale assault on the citidel. Echoes, Reilly, a chorus of echoes, some on harmony some off key, but all are echoes, of SR I see.

Here is the experimental arrangement, I bet it looks familiar, doesn't it Reilly? "relativity" pages 25-27 you mean? My favorite science book of all time. Check it out.
---> motion

A________________M______|_______|______B
M'(t0) M'(t1) M'(t2)

M is the midpoint of photon emitters at A and B. M'(t0) is the observer location on the moving frame that coincides with M in the stationary frame just as the photons were emitted simultaneously at A and B.
Later the Oberver detects the B photon at M'(t1) and then the photon from A at M'(t2). This is the Einstein train experiment that has been passing through the threads lately. And t'' ithe signals from A and B at the midpoint of A and B (for a long train).

IF SR predicts that the photons were not emitted simultaneously in the moving frame describe the location of the A photon when the B photon was detected at M'(t1) in terms of t's and v, the velocity known by the observer wrt to the stationary frame.

Simple high school algebra Reilly, you shouldn't have any problem, especially as I have already done the math.

Thank you for your help.

geistkiesel

Jun21-04, 08:00 PM

Grounded -- First, please accept my apologies for being snotty and arrogant(the physicist's disease) I misjudged your zeal and passion for understanding. (Note, however, as my dear Mother told me -- You learn more with your mouth shut than with it open)

Physics is very difficult, for two primary reasons: it requires a real facility with and understanding of a lot of advanced math; the conceptual basis is highly abstract and idealized, in E&M, QM, SR, GR, ....., and is not fully consistent. So, particularly, for the last reason, most physicists are highly pragmatic -- do the best you can with what you have, don't sweat the hard stuff unless it messes up your work. As I'm sure you know, for example, there is huge controversy about the proper interpretation of QM, but many working physicists pay little attention to the controversy. The standard ways work just fine in practice.

Everyone who teaches physics, say SR, will tell you we did not understand SR until we taught it. It takes a long time, and many exposures to SR to get it right. And, most students of SR will tell you that sometimes you have to suspend your judgement to get to a good understanding -- that's the advantage of a good teacher, he/she can suggest what to sweat now, and what to defer. All told, SR is a huge subject, of which the basic space-time kinematics, the x's and t's, comprise only a very small portion. It is the totality of SR that is so compelling.

That being said, the path to a robust understanding of SR necessarily involves lot's of math -- there's no way around that fact.

Tom's explanation of the imaginary exponential is right on. The way, typically, you build up a comfortable intuition about i, the square root of -1, is to work with it, work with it a lot. It's part of the language of physics, and is used so much because it is a powerful tool in working with waves, periodic phenomena, much of QM, and many other branches of physics and engineering.

If you are serious about physics, you need to hit the books, and do the homework. Resnick and Halliday is a good place to start. And, absolutely necessary, learn calculus. Then you will understand that the x and t in the exponential are not x2-x1, t2-t1. That exponential gives you the compex value of the wave amplitude at x at time t.

Once a professor, always a professor.
Regards and good luck

Reilly Atkinson

Reilly, I don't know if you have read all of the posts Grounded has made in this thread, but a cursory examination will show you that he making a most robust effort to teach you something, but your instincts seem to be to throw the dust of whatever subtle discouragement you have to the man. Condescending, superior intelligence, education and wit you know the attitue, don't you?. When you understand what he is saying, meaning you have to read it of course, you can understand his tenacity he has built into the model he his presenting.

Again, Reilly. he is teaching you something. Physics isn't so difficult, but useless phyiscs is very difficult, don't you agree?.

geistkiesel

Jun21-04, 08:08 PM

Might I recommend a bit more exposition then? The quick two-liners simply do not convey the information you wish to convey.

Here's a perfect example.

On what basis do you say that something is wrong with an experiment, as opposed to something being wrong with a theory?
Tom, Grounded showed by example the necessity of including the observers relative velocity less a mistake be made in the measurement of the length of the cars (wave length of light). The SR system creates a mistake in measuremment and needed to create SR to explain the error. How many times can you echo "the vast amount of experimental results" describing your collective error? The experiments that prove time dilation, contraction of matter, loss of simultaneity?

How long can you keep it up before the echo wears thin? Tom, lifting the weight of SR will be a relief, a huge relief.

They're are errors Tom, great big huge errors.

geistkiesel

Jun22-04, 07:53 AM

russ_watters

Jun22-04, 10:25 AM

Why do you steer the conversation around to faith and pain and conviction? Simple: your position defies rational explanation. Indeed, you actively repel any attempt at rational discussion. You ignore evidence and you ignore math. These discussions are not scientific because you refuse to be scientific in your approach to the problem.

Hurkyl

Jun22-04, 04:46 PM

Why do you steer the conversation around to faith and pain and conviction?

If you didn't want your opinions and beliefs questioned directly, then you shouldn't state them in a discussion forum.

I've yet to understand why people who state (or imply) such things feel they should be immune from scrutiny.

wespe

Jun22-04, 05:14 PM

An interferometer can be calibrated using a light source with a known wavelength. As long as the distance between the observer and the source are not changing, this will work. Since light travels 186,000 miles per second, the wavelength equals the amount of distance traveled, traveling at 186,000 miles per second, in the amount of time it takes the light to complete one cycle. If the distance between the observer and the source are decreasing, then the wavelength equals the amount of distance traveled, traveling at the sum of “186,000 miles per second” added to “the speed at which the distance between the source and the observer is decreasing”, in the amount of time it takes the light to complete one cycle. If we measure the wavelength in this fashion, we will not measure a change.

Are you still there, Grounded?

I see no reason to for any calibration, but apart from that, I don't think an interferometer can be calibrated in such a way that it will always measure the "true" wavelength (the wavelength in the emitter's frame). You can't even calculate the "true" wavelength by just knowing the measured relative frequency (and the speed of light, which is constant), you also have to know the relative speed [between you and the light source]. You can calibrate [at a certain relative speed], but then it will not work [when the relative speed changes]. You must constantly "calibrate" it by feeding it with the value of relative speed, then what kind of calibration is that? What do you think?

editing to add:
Am I misunderstanding? You are saying that a "true" wavelength exists independent of the relative speed. Then you should be able to measure it without taking relative speed into account. Therefore your calibration must not involve relative speed. Right? Also, the "traveled distance" is the result of relative speed. Actually, according to yourself, you aren't going anywhere. It is the other object that travels. Without relative speed, there is no meaning to traveled distance.

grounded

Jun22-04, 05:47 PM

Whether you are using Galilean relativity or SR, the equation is the same.

I can calculate the relative velocity between a light pulse and myself by measuring the following:

Event 1: Pulse Emitted
x1=Location of emitter on x-axis at time t1.
t1=Time of emission.

Event 2: Pulse Detected
x2=Location of detector on x-axis at time t2.
t2=Time of detection.

The speed of the pulse relative to me is then:

v=(x2-x1)/(t2-t1).

For light, this will always come out to be c. And as you can see, that result is not "built in" to the way we calculate relative speed. It is a simple, undeniable experimental fact.

Tom, you say it is not "built in", but consider the following;

Can you calculate the relative velocity between a moving car and yourself by measuring the following?

Event 1: Car Accelerated (Assume instantaneous acceleration to 60 Miles Per Hour)
x1=Location of car on x-axis at time t1.
t1=Time of acceleration.

Event 2: Car Detected
x2=Location of car on x-axis at time t2.
t2=Time of detection.

The speed of the car relative to you is then:

v=(x2-x1)/(t2-t1).

Can you alter the relative speed of the car while using this formula?
If not, then how is this formula the very definition of relative speed?

grounded

Jun22-04, 06:20 PM

Are you still there, Grounded?

I see no reason to for any calibration, but apart from that, I don't think an interferometer can be calibrated in such a way that it will always measure the "true" wavelength (the wavelength in the emitter's frame). You can't even calculate the "true" wavelength by just knowing the measured relative frequency (and the speed of light, which is constant), you also have to know the relative speed [between you and the light source].

I agree...partly.

The relative speed IS the distance the observer travels towards (or away from) the source in one second, which IS the same thing as the change in distance between the observer and the source per second.

This is why I say we must include the distance the observer has traveled relative to the source in order to accurately measure the wavelength.

The speed of light is calculated to be constant because we use an incorrectly measured wavelength.

You can calibrate [at a certain relative speed], but then it will not work [when the relative speed changes]. You must constantly "calibrate" it by feeding it with the value of relative speed.

If the change in distance between the observer and the source is not at a constant velocity, then yes, it must be constantly calibrated.

wespe

Jun22-04, 06:31 PM

This is why I say we must include the distance the observer has traveled relative to the source in order to accurately measure the wavelength.

The speed of light is calculated to be constant because we use an incorrectly measured wavelength.

OK, suppose I claim the following:

"There exists a true frequency and we are measuring it wrong. Because we must include relative speed [or, the distance the observer has traveled relative to the source] in order to accurately measure the frequency. We must calibrate our equipments constantly according to the relative speed."

Do you see? If you do such a correction on wavelength, you must also do it for frequency. And with both wavelength and frequency "corrected", you get constant c when you multiply them. That's what I meant by "mixing frames" in an earlier post.

grounded

Jun22-04, 06:35 PM

Am I misunderstanding? You are saying that a "true" wavelength exists independent of the relative speed. Then you should be able to measure it without taking relative speed into account.

I am saying that if you account for the change in distance between the observer and the source, you can always measure the true wavelength.

From my original post:

Traveling towards the train will increase the number of boxcars that are passed and it will increase the relative speed between the observer and the train, but it will not change the length of the boxcars. If the observer plotted the number of boxcars that passed in one minute on a four-inch line, and then did the same thing after increasing speed towards the train, the second experiment would have more marks on the four-inch line and they would be closer together. This does not mean the length of the boxcars have gotten shorter, it means that the four-inch line represents a greater distance while traveling towards the source than it does when not moving relative to the source.

jcsd

Jun22-04, 06:38 PM

I am saying that if you account for the change in distance between the observer and the source, you can always measure the true wavelength.

From my original post:

But the problem is the light is not atatched to the refernce frame of the source, what happens when the source is accelarting? what happens when the source is unknown?

grounded

Jun22-04, 06:47 PM

OK, suppose I claim the following:

"There exists a true frequency and we are measuring it wrong. Because we must include relative speed [or, the distance the observer has traveled relative to the source] in order to accurately measure the frequency. We must calibrate our equipments constantly according to the relative speed."

Do you see? If you do such a correction on wavelength, you must also do it for frequency. And with both wavelength and frequency "corrected", you get constant c when you multiply them. That's what I meant by "mixing frames" in an earlier post.

Current measurments of frequency already include the distance the observer has traveled relative to the source. The change in distance between the source and the observer in one second, divided by the true wavelength, equals the change in frequency.

We include the distance the observer has traveled relative to the source when measuring frequency, but we do not include it when measuring wavelength, which is why the relative speed can never change.

The frequency wrt the observer equals the number of cycles that pass by the observer due to the velocity of the light, added to the number of cycles passed caused by the observers speed towards the source.

Like you said, what we do to one, we must do to the other.

wespe

Jun22-04, 07:07 PM

Current measurments of frequency already include the distance the observer has traveled relative to the source. The change in distance between the source and the observer in one second, divided by the true wavelength, equals the change in frequency.

We include the distance the observer has traveled relative to the source when measuring frequency, but we do not include it when measuring wavelength, which is why the relative speed can never change.

The frequency wrt the observer equals the number of cycles that pass by the observer due to the velocity of the light, added to the number of cycles passed caused by the observers speed towards the source.

Like you said, what we do to one, we must do to the other.

OK

Let's say, according to light source: the frequency is 300,000 Hz and wavelength is 1 km.

Due to some relative speed..
The observer measures: frequency is 600,000 Hz, wavelength is 0,5 km
The observer calculates: relative speed = relative frequency x relative wavelength = 300,000 km/sec
The observer can also directly measure relative speed like I described in an earlier post. This measurement verifies the calculated relative speed: 300,000 km/sec

According yo you: true wavelength is 1 km, but true frequency is still 600,000 Hz
So observer must calculate: relative speed = 600,000 km/sec
This result does not match the directly measured relative speed. What do you say about that?

grounded

Jun22-04, 07:10 PM

But the problem is the light is not atatched to the refernce frame of the source, what happens when the source is accelarting? what happens when the source is unknown?

To say the source is traveling towards the observer at a faster rate, is the same thing as saying the observer is traveling towards the source at a faster rate, assuming the observer was already traveling towards the source.

Like Tom has said, it is not the speed of the observer or the speed of the source that is important, it is the amount of change in distance between the source and the observer in one second that matters.

We can use a spectrometer and a spectrograph to analyze and discover what the source is made of and what its true wavelength is. The amount of shift in the spectrum will tell you the relative speed. This shift is caused by not changing the scale.

jcsd

Jun22-04, 07:32 PM

To say the source is traveling towards the observer is the same thing as saying the observer is traveling towards the source at a faster rate, assuming the observer was already traveling towards the source.

Like Tom has said, it is not the speed of the observer or the speed of the source that is important, it is the amount of change in distance between the source and the observer in one second that matters.

We can use a spectrometer and a spectrograph to analyze and discover what the source is made of and what its true wavelength is. The amount of shift in the spectrum will tell you the relative speed. This shift is caused by not changing the scale.
No it is not because accelartion is npot relative in the same way asvelcotiy is relative you can't transform an accelarated frame into an inertail frame in special relatvity.

grounded

Jun22-04, 07:32 PM

What do you say about that?

I say I am extremely interested in learning about a real world experiment such as you described, minus the spaceship. Remember, it must be done while in motion relative to the source. A link describing the details of the experiment would be appreciated.

grounded

Jun22-04, 07:44 PM

No it is not because accelartion is npot relative in the same way asvelcotiy is relative you can't transform an accelarated frame into an inertail frame in special relatvity.

Is not the change in distance between the observer and the source (at any point) the same to the observer as is it is to the source?

grounded

Jun22-04, 07:51 PM

According yo you: true wavelength is 1 km, but true frequency is still 600,000 Hz

True frequency is measured while at rest relative to the source.

While in motion, the frequency is relative. Traveling towards the train will increase the number of boxcars that are passed and it will increase the relative speed between the observer and the train, but it will not change the length of the boxcars.

Frequency is relative
Speed is relative
Wavelength is NOT relative

jcsd

Jun22-04, 07:52 PM

Is not the change in distance between the observer and the source (at any point) the same to the observer as is it is to the source?
The instanateous relativce velcoities are the same, but the accelartions are different.

grounded

Jun22-04, 08:23 PM

The instanateous relativce velcoities are the same, but the accelartions are different.

I see what you mean, and I agree, if you mean that one will feel the change in velocity and the other will not.

ram1024

Jun22-04, 08:46 PM

to say that a wavelength <of light> is not relative must mean that everything you can measure it with is not realative as well. ie> length contraction does not exist.

i don't think it exists either, but maybe you have a different explanation?

wespe

Jun22-04, 10:40 PM

I say I am extremely interested in learning about a real world experiment such as you described, minus the spaceship. Remember, it must be done while in motion relative to the source. A link describing the details of the experiment would be appreciated.

Grounded....

I am simply saying that by "correcting" the measured wavelength, you are creating a paradox.

Please do consider:

Assume, once again, according to the light source: the frequency is 300,000 Hz and wavelength is 1 km.

Assume, the approaching observer measures: frequency as 600,000 Hz and wavelength as 0,5 km

You say: "Current measurments of frequency already include the distance the observer has traveled relative to the source"
So, we will NOT correct the measured frequency, right? So we have this number: 600,000 Hz

You say: "We do not include it when measuring wavelength"
So, we WILL correct the measured wavelength, right? So we get this corrected number: 1 km

Now, how will we calculate the relative speed of light wrt us? By multiplying the wavelength by frequency, right?
So we calculate 600,000 Hz x 1 km = 600,000 km/sec, right?

You say we think relative speed never changes, because we don't correct the wavelength, right? So, when we use the corrected wavelength, we find 600,000 km/sec. OK?

Now, I am telling you that the relative speed can be measured directly, without measuring wavelength or frequency, just by timing the passage of light over a distance. And, this directly measured relative speed is ALWAYS equal to 300,000 km/sec. This is confirmed by REAL experiments.

Therefore, the calculated relative speed with the "corrected" wavelength" is WRONG.
The calculated relative speed without any corrections to wavelength is CORRECT.
Therefore, correcting wavelength as you want is WRONG.

Now please just tell me which argument above you think is faulty.

Is it only the "This is confirmed by REAL experiments" part? Will you be convinced if there were such real experiments?

wespe

Jun22-04, 11:07 PM

True frequency is measured while at rest relative to the source.

While in motion, the frequency is relative. Traveling towards the train will increase the number of boxcars that are passed and it will increase the relative speed between the observer and the train, but it will not change the length of the boxcars.

Frequency is relative
Speed is relative
Wavelength is NOT relative

What you are saying is approximately correct for slow trains. But if you increase the relative speed of a train close to the speed of light, it isn't correct anymore.

Because, as the speed increases, length contraction effect becomes more, and the length of the train cars are no longer measured the same; it is measured much less.

And when you reach exactly light speed (not possible for trains), the relative speed becomes constant, wavelength and frequency becomes variable [for light] *

So is it just that you don't buy length contraction? What about time dilation?

Edit:
* I'm not so sure about this part. Here's what I thought: Suppose a rocket is launched from earth and achieves a relative speed of 299,000 km/sec wrt earth. Then, a second rocket is launched in the same direction and achieves a relative speed of 298,000 km/sec wrt earth. What is the relative speed between the rockets as measured by the rockets?

http://math.ucr.edu/home/baez/physics/Relativity/SR/velocity.html
The formula at the end of the page is:
w = |ux - vx| / (1 - ux vx/c2)

I calculated it will be around 100,000 km/sec. So I thought: as the speed of the first rocket approaches 300,000 km/sec, this value will also approach 300,000 km/sec, and at the limit it will be constant just like light.

David

Jun22-04, 11:39 PM

Because, as the speed increases, length contraction effect becomes more, and the length of the train cars are no longer measured the same; it is measured much less.

snip

So is it just that you don't buy length contraction? What about time dilation?

“Assertions about the shape of a body in nonaccelerated motion therefore have a direct meaning. The shape of a body in the sense indicated we will call its ‘geometric shape.’ The latter obviously does not depend on the state of motion of a reference frame.” A. Einstein, 1907 Vol. 2 of Collected Papers.

He backed down on length contraction. He changed his mind. Read his own papers and stop believing internet rumors posted on websites like this one.

David

Jun22-04, 11:44 PM

By 1911-12, Einstein retracted his light speed “constancy” postulate. For example, in the 1912 paper, “The Speed of Light and the Statics of the Gravitational Field,” he said:

“But at the same time it turned out that one of the basic principles of that theory, namely, the principle of the constancy of the velocity of light, is valid only for space-time regions of constant gravitational potential. Even though this result rules out the universal applicability of the Lorentz transformation, it should not frighten us away from the further pursuit of the path we have taken...”

And in the 1912 paper, “Relativity and Gravitation”, he says:

“Abraham notes that I have delivered the coup de grace to the relativity theory by abandoning the postulate of the constancy of the velocity of light and by the therewith connected relinquishment of the invariance of the systems of equations with respect to the Lorentz transformations.”

This was in response to statements that Max Abraham published in the Annalen der Physik:

“Already before a period of one year, A. Einstein, by accepting an influence of the gravitation potential on the speed of light, gave up the postulate of the constant speed of light essential for his earlier theory 1); in a work appeared recently 2)......”

So, the famous “constancy” postulate of the 1905 SR theory did not exist after 1912, and it doesn’t exist today.

In the 1912 paper, “Theory of Relativity”, as published in “Physik”, Emil Warburg, Leipzig, 1915, he said this about the SR theory:

“Finally, one more important question: Does the theory of relativity possess unlimited validity? Even the supporters of the theory of relativity have different views on this question. The majority are of the opinion that the propositions of the theory of relativity – especially its conception of time and space – can claim unilmited validity.

However, the writer of these lines is of the opinion that the theory of relativity is still in need of a generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned.”

Stop believing rumors and urban legends.

wespe

Jun22-04, 11:46 PM

“Assertions about the shape of a body in nonaccelerated motion therefore have a direct meaning. The shape of a body in the sense indicated we will call its ‘geometric shape.’ The latter obviously does not depend on the state of motion of a reference frame.” A. Einstein, 1907 Vol. 2 of Collected Papers.

He backed down on length contraction. He changed his mind. Read his own papers and stop believing internet rumors posted on websites like this one.

I don't know if he changed his mind, maybe while developing the theory? I don't know. But please see:

http://www.bartleby.com/173/10.html

"Thus the length of the train as measured from the embankment may be different from that obtained by measuring in the train itself"

Isn't this book dated 1920?

wespe

Jun23-04, 12:12 AM

“Already before a period of one year, A. Einstein, by accepting an influence of the gravitation potential on the speed of light, gave up the postulate of the constant speed of light essential for his earlier theory 1); in a work appeared recently 2)......”

So, the famous “constancy” postulate of the 1905 SR theory did not exist after 1912, and it doesn’t exist today.

Well you got me there; I don't know much about GR.

But, I thought speed of light is measured constant even under the influence of gravity.

Are you sure these aren't out-dated historical records?

What do you say about that 1920 book?

ahrkron

Jun23-04, 03:17 AM

David,

It is a well known fact that AE tried various models before arriving to what we now know as GR, aknowledged and understood both by biographers, like Abraham Pais, and by those who study the origins of relativity, like John D. Norton. It is not new (or any kind of "big secret") that there were contradictions in his papers from that period. You are precisely choosing papers from before 1916, which is roughly when he arrived to the theory's final form.

If you are going to put so much weight on AE own words, why don't you at least use the version that he regarded as the best way to put things together? otherwise, you seem to be trying to advocate for the ideas that AE, and many others now, understood to be faulty.

swansont

Jun23-04, 06:11 AM

While in motion, the frequency is relative. Traveling towards the train will increase the number of boxcars that are passed and it will increase the relative speed between the observer and the train, but it will not change the length of the boxcars.

Frequency is relative
Speed is relative
Wavelength is NOT relative

Argument by analogy is a dangerous thing, because if you take the analogy too far you can reach erroneous conclusions. Consider the possibility that light and trains might behave differently.

grounded

Jun23-04, 06:15 PM

Argument by analogy is a dangerous thing, because if you take the analogy too far you can reach erroneous conclusions. Consider the possibility that light and trains might behave differently.

It’s not that they behave differently, it’s that we calculate them differently.

If you measure the train like we measure the light, then the speed of the train will never change.
If you measure the light like we measure the train, then the length of the boxcar will never change.

What are your thoughts on post #141? (http://www.physicsforums.com/showpost.php?p=240485&postcount=141)

reilly

Jun23-04, 07:03 PM

Reilly, I don't know if you have read all of the posts Grounded has made in this thread, but a cursory examination will show you that he making a most robust effort to teach you something, but your instincts seem to be to throw the dust of whatever subtle discouragement you have to the man. Condescending, superior intelligence, education and wit you know the attitue, don't you?. When you understand what he is saying, meaning you have to read it of course, you can understand his tenacity he has built into the model he his presenting.

Again, Reilly. he is teaching you something. Physics isn't so difficult, but useless phyiscs is very difficult, don't you agree?.

With all due respect, there's a cottage industry, almost 100 years old, devoted to proving Einstein wrong. I've been familiar with this industry about 40 years, so, in fact, I've encountered arguments like yours and Grounded's numerous times. They don't change much from year-to-year, and they virtually all attempt to prove that the basic Einstein description of space time via the Lorentz transformation is wrong. After all, there are only so many ways to attack the Lorentz transformation in its space-time version. Physics departments around the world every week get many letters outlining ideas like your and Grounded's. Nonetheless SR is alive and well in its world of inertial frames.

One difference between the anti-Einstein folks and the standard physics community is that the history of standard physics is recorded and open to all. There appears to be little or no extant history of the anti-Einstein movement, so people keep doing the same things over and over and over, never learning from their forbearers, and seldom learning the true extent of SR in physics today. Those who neglect history are doomed to repeat it.

I've seen a few attempts to get at E=mc**2, but not many. I've never encountered an attack on, say, the successful use of SR in accelerator design, or the relativistic description of electron-proton scattering, or the Thomas precession, and on-and-on. What the anti-Einstein folks don't realize is that SR is fundamental to physics in thousands of ways, and has been 'verified' thousands of times -- if SR were wrong, physics today would be very different than it is.

Those of you who, for one reason or another, choose to attack SR would be well advised to develop a good sense of the myriad ways in which it has been tested - and SR has yet to fail. The freshman physics version of SR is fallow territory. The vulnerabilities, if there are such, are in the far more difficult, albeit subtle parts of physics, like providing a rigorous formulation of the relativistic dynamics of a gas, in either classical or quantum form. Perhaps the difficulties of quantum field theory might be another point of attack.

Relativistic kinematics is, in my judgment, the bedrock of experimental tests of SR. Pauli's successful conjecture of the neutrino depended totally on the validity of SR. Key experiments like the discovery of the Omega minus particle, which confirmed the correctness of an important SU3 multiplet, the experiments elucidating the K meson system, and all the experiments demonstrating the correctness of the quark hypothesis require the utility and correctness of SR.

If, after 40 years of perusing anti-SR arguments, I have anything to learn it is first, why do people go after Einstein? Why do they not learn from history? And why do they not attack relativistic kinematics? -- remember that there is a strong duality in both classical and quantum physics between position and momentum, time and energy. Enough.
Regards,
Reilly Atkinson

russ_watters

Jun23-04, 08:01 PM

If, after 40 years of perusing anti-SR arguments, I have anything to learn it is first, why do people go after Einstein? Why do they not learn from history? And why do they not attack relativistic kinematics? -- remember that there is a strong duality in both classical and quantum physics between position and momentum, time and energy. Enough.I have wondered this too (though only for about 2 years :wink: ). The best I can think of is that Einstein's Relativity is the first thing they hear about that they can't get their arms around - and they never get past it. They simply can't accept reality at face value.

Nereid

Jun23-04, 09:38 PM

I have wondered this too (though only for about 2 years :wink: ). The best I can think of is that Einstein's Relativity is the first thing they hear about that they can't get their arms around - and they never get past it. They simply can't accept reality at face value.But why aren't there similar or greater volumes of attacks on QFT/QM? That's surely far weirder (is that a word?). Maybe it has something to do with AE vs a big mob (Heisenberg, Dirac, Pauli, Schrödinger, Bohr, ...)? :confused:

wespe

Jun23-04, 11:57 PM

But why aren't there similar or greater volumes of attacks on QFT/QM? That's surely far weirder (is that a word?). Maybe it has something to do with AE vs a big mob (Heisenberg, Dirac, Pauli, Schrödinger, Bohr, ...)? :confused:

Being one of them myself formerly, I guess, quantum theory talks about small intangible things and people can't think of counter examples for them. Not so when you talk about trains, lightenings, twins..

swansont

Jun24-04, 06:05 AM

It’s not that they behave differently, it’s that we calculate them differently.

Really? Trains follow Maxwell's equations?

If you measure the train like we measure the light, then the speed of the train will never change.
If you measure the light like we measure the train, then the length of the boxcar will never change.

What are your thoughts on post #141? (http://www.physicsforums.com/showpost.php?p=240485&postcount=141)

I think that if you look carefully you'll see that you aren't comparing the same thing. x2 also represents where you are, but that isn't apparent in your equation. If you are moving, x2 will be different, and so will t2, for the car example.

russ_watters

Jun24-04, 10:58 AM

But why aren't there similar or greater volumes of attacks on QFT/QM? That's surely far weirder (is that a word?). Maybe it has something to do with AE vs a big mob (Heisenberg, Dirac, Pauli, Schrödinger, Bohr, ...)? :confused: I agree that they are weirder (yes, thats a word), but most people never learn that those things are weird. The double-slit experiment doesn't become weird until you quantize light and you don't really start digging into that in high school physics. They say there is a wave-particle duality in high school and they explore the wave and particle properties, but they don't mix them - they don't address (or even make you aware of) the contradictions that arise from them.

I first read "A Brief History of Time" in high school and that was my first real exposure to non-newtonian physics. Its mostly Relativity, but it touches on QM. I didn't dig any deeper into QM though, until much later (though I picked up bits and piece here and there).

Then again, it may just be that Einstein was a cult-of-personality like no other scientist before or since.

Nereid

Jun24-04, 12:32 PM

Being one of them myself formerly, I guess, quantum theory talks about small intangible things and people can't think of counter examples for them. Not so when you talk about trains, lightenings, twins..Cats? Surely people can relate to the angst of Erwin's moggie? :tongue2:

swansont

Jun24-04, 12:47 PM

It was actually Mrs. Schroedinger's (http://home.netcom.com/~swansont/flipacoin.jpg) cat.

grounded

Jun24-04, 12:56 PM

I think that if you look carefully you'll see that you aren't comparing the same thing. x2 also represents where you are, but that isn't apparent in your equation.

x2=Location of car on x-axis at time t2

t2=Time of detection

x2 is where you and the car will be at t2 (you are the detector, you detect it when you run into it)

If you are moving, x2 will be different, and so will t2, for the car example.

x2 and t2 is simply the place and time you run into (or detect) the car. If you are moving towards the car, then the distance the car has to travel before hitting you is decreased since you are closer to it, and since the distance is decreased so is the amount of time it takes the car to travel that distance. 60 MPH is the same thing as 30 Miles Per 1/2 Hour.

If you are traveling away from the car, the car will have to travel a further distance from x1 to run into you (x2 - x1). Since it travels a further distance, it will take more time to run into you (t2 - t1). The relative speed never changes.

Is that how you see it?

Post #141 (http://www.physicsforums.com/showpost.php?p=240485&postcount=141)

David

Jun25-04, 12:11 AM

I don't know if he changed his mind, maybe while developing the theory? I don't know. But please see:

http://www.bartleby.com/173/10.html

"Thus the length of the train as measured from the embankment may be different from that obtained by measuring in the train itself"

Isn't this book dated 1920?

Yes, you’re right. The problem is, he lied in some of his books and papers. He flip-flopped many times on many issues, saying one thing in one paper and the opposite in a different paper. The book you are talking about was published in Germany in 1916, and many German physicists were mad at him because of his lying and deceptions.

I’ve been investigating this for years, and I’ve got a lot of his early papers that not too many people know about.

He got many of the ideas for his SR theory from the 1895 Lorentz electrodynamics theory. It was Lorentz who invented time dilation, length contraction, the speed limit of c, mass increase with motion, the relativistic Doppler effect, and the Lorentz transformation equations.

Here is a list of a few things he said in different books and papers:

Einstein first said in 1905 that “light is always propagated in empty space with a definite velocity c”.

Then in 1911 and his 1916 paper he said that light speed was not constant because it slowed down in a gravity field.

In his 1916 book he said it was constant (in the first few chapters), then in a later chapter he said it wasn’t constant.

In 1916 he said all galaxies and stars were “fixed”, then in a 1932 paper he said the galaxies were moving radially at high speeds.

He said in 1916 the universe was not expanding, then in 1932 he said it was.

In 1916 he said large-scale universal space was “curved”, but in 1932 he said it wasn’t.

In 1916 he said that a “cosmological constant” kept all the stars from collapsing in on themselves, then in 1932 he said there was no such thing as a cosmological constant.

In 1905 he said that only one of two relatively moving clocks could slow down due to the relative motion, but in 1918 he said that both of two relatively moving clocks would slow down due to the relative motion.

In 1905 he said there was “no ether”, but in 1918 and 1920 he said there was an “ether.”

In 1905 he said that relative motion caused geometric “length contraction”, then in 1907 he said that relative motion could NOT cause geometric length contraction. Then in 1916 he again said that it could cause length contraction.

For several years he told newspaper reporters that he invented the special relativity theory, but in 1920 he told a New York Times reporter that he and Lorentz invented it.

In 1905 he had “balance-wheel” clocks slowing down due only to “relative motion”, but in 1918 he had to use atomic clocks, acceleration effects, and gravity fields to try to “resolve” his 1905 clock paradox.

In 1905 he said that both the K and K’ systems in his SR theory were non-accelerating Galilean inertial systems, but in 1918 he said that the K’ system in the SR theory was NOT a Galilean inertial system and was accelerated.

In 1916 he said that the SR theory did NOT consider gravitational fields, but in 1918 he said that the SR theory DID consider gravitational fields.

Newton, not Einstein was the first to propose that light would bend when it passed the sun and other bodies. He said this in the 1704 edition of his “Optics”.

Newton, not Einstein or Hubble was the first to propose the fundamental “big bang” hypothesis. He called it a “projectile force” or “projectile impulse” that set all the astronomical bodies flying apart. He said this in some of his letters to Bentley.

Einstein's cult of followers are trying to cover up his errors and lies. That’s why I am banned from posting anything on the relativity sections on this board.

David

Jun25-04, 12:15 AM

David,

It is a well known fact that AE tried various models before arriving to what we now know as GR, aknowledged and understood both by biographers, like Abraham Pais, and by those who study the origins of relativity, like John D. Norton. It is not new (or any kind of "big secret") that there were contradictions in his papers from that period. You are precisely choosing papers from before 1916, which is roughly when he arrived to the theory's final form.

Your moderator Russ claims the "constancy" postulate is still in effect.

David

Jun25-04, 12:23 AM

David,

If you are going to put so much weight on AE own words, why don't you at least use the version that he regarded as the best way to put things together? otherwise, you seem to be trying to advocate for the ideas that AE, and many others now, understood to be faulty.

Then why can’t this be discussed on this board’s SR pages? The management says we can’t post anything that challenges the validity of the 1905 paper. I got banned from those pages because I proved that Einstein changed his mind and corrected some of the errors of the SR theory, but management here is pretending there are no errors in SR and that Einstein never made any changes in it.

The Einstein cult that runs the board doesn’t want anyone to quote any later papers in which Einstein changed his mind about things he said in the SR theory. These guys are essentially carrying out a hoax, pretending that there are no flaws in SR theory and that Einstein never made any changes in it.

This is part of the political promotion of Einstein as the “world’s smartest man”. It’s a hero-worship cult. I run into this on other message boards too.

wespe

Jun25-04, 12:51 AM

Yes, you’re right. The problem is, he lied in some of his books and papers. He flip-flopped many times on many issues, saying one thing in one paper and the opposite in a different paper. The book you are talking about was published in Germany in 1916, and many German physicists were mad at him because of his lying and deceptions.

I’ve been investigating this for years, and I’ve got a lot of his early papers that not too many people know about.

Well, okay, let's say he took ideas from other people and he changed his mind a few times, etc. But it would be wrong to say his contribution was null. I think he was the only one to combine all the ideas and dismiss aeather. Also he got nobel prize for explaining photoelectriic effect. I may be wrong in these. Anyway, that's history. The important thing is that there is currently a standard theory. There may be text books with erros, even professors may disagree with each other. It's not like a holy book you know. In the end it is the experiments that decide what is right and what is wrong. Therefore, in my opinion, your attacks on a dead man is not too beneficial.

[
sorry if I sound cocky.
regards.
]

David

Jun25-04, 06:38 AM

Well, okay, let's say he took ideas from other people and he changed his mind a few times, etc. But it would be wrong to say his contribution was null. I think he was the only one to combine all the ideas and dismiss aeather. Also he got nobel prize for explaining photoelectriic effect. I may be wrong in these. Anyway, that's history. The important thing is that there is currently a standard theory. There may be text books with erros, even professors may disagree with each other. It's not like a holy book you know. In the end it is the experiments that decide what is right and what is wrong. Therefore, in my opinion, your attacks on a dead man is not too beneficial.

[
sorry if I sound cocky.
regards.
]

You don't sound cocky at all.

Of course his contributions were not “null”.

In my opinion his best work was in early atomic physics. His early atomic papers are absolutely brilliant. This is actually what he was famous for in the physics community and why he received the Nobel Prize. I don’t have any problem with that. He was quite smart about atomic physics.

What I have a problem with is all the Einstein-worship websites and books that say there are no flaws in SR theory, and so many cultists on the internet teaching teenagers the wrong physics information based on SR theory.

There is no current “standard theory” because it keeps changing. For example, just 10 years ago universities taught that the most distant galaxies were not moving at faster than the speed of light relative to the earth, but now many of the universities are teaching that they do move faster than light relative to the earth.

A type of “ether” theory has been re-introduced to astronomy with “co-moving local space” acting as a “local ether”.

It is not good in any science field when someone is banned from science forum topics because they point out that the SR theory contains errors and that Einstein himself corrected some of the errors.

This is not “science”, this is a “science cult”. The quest is not for “truth” or “knowledge”, but to promote the Holy Worshipped One. This is pseudo science masquerading as mainstream science.

My “attacks” are not on the dead man. If he were alive today he would be astounded at the amount of false information being spread on the internet in his name. He would be outraged.

He didn’t have the benefit of certain astronomical information we have today, so he had to guess about a lot of stuff a hundred years ago. He thought the universe was not “expanding” because virtually all the astronomers in the 1916 era said it wasn’t expanding. If he were alive today there would be plenty of things he would clear up about his early time and motion papers, because at last he would have the necessary observational information to make some final decisions. He flip-flopped on some issues a hundred years ago, but so did other physicists. But for Einstein cultists today to claim that he was always perfect, never flip-flopped, never fibbed or fudged, then that is just gross “hero worship”, which has no place in physics or science. It’s like Elvis worship. But Elvis worship does not belong in science.

Hurkyl

Jun25-04, 06:57 AM

Gasp, Einstein didn't come out of the womb already knowing the form of GR and SR we use today? My entire worldview has been shattered. :cry:

If I may hazard a guess, the reason you are banned from the relativity forums because your topic is Einstein, not relativity. Worse, you have this nasty habit of hijacking threads to start this discussion, instead of giving it its own thread.

swansont

Jun25-04, 09:23 AM

x2=Location of car on x-axis at time t2

t2=Time of detection

x2 is where you and the car will be at t2 (you are the detector, you detect it when you run into it)

OK, thanks for clarifying. I wasn't sure you were actually measuring the car by collision - now I am.

x2 and t2 is simply the place and time you run into (or detect) the car. If you are moving towards the car, then the distance the car has to travel before hitting you is decreased since you are closer to it, and since the distance is decreased so is the amount of time it takes the car to travel that distance. 60 MPH is the same thing as 30 Miles Per 1/2 Hour.

If you are traveling away from the car, the car will have to travel a further distance from x1 to run into you (x2 - x1). Since it travels a further distance, it will take more time to run into you (t2 - t1). The relative speed never changes.

Is that how you see it?

Post #141 (http://www.physicsforums.com/showpost.php?p=240485&postcount=141)

I think I understand your point. But x2 is where I am, so it's actually fixed in my coordinate system. If you want to look at it from another point of view, you have to properly transform everything.

grounded

Jun25-04, 12:10 PM

But x2 is where I am, so it's actually fixed in my coordinate system. If you want to look at it from another point of view, you have to properly transform everything.

x2 and x1 are specific spots on the highway.

x1 = Location of car on the highway at time of acceleration.

x2 = Location of car on the highway at time of detection.

I'm not sure what point of view you are talking about, since the locations on the highway are the same for everyone, we could mark them with a flag at the time of measurement.

I also don't know what transformation you're referring to, if you do change the distance then you must equally change the time, else the answer will vary. SR equations are designed to always give the same answer; they were created off from Einstein's two postulates. The idea came first, then the math, that is why the math always proves the idea.

grounded

Jun25-04, 12:59 PM

What you are saying is approximately correct for slow trains. But if you increase the relative speed of a train close to the speed of light, it isn't correct anymore.

Because, as the speed increases, length contraction effect becomes more, and the length of the train cars are no longer measured the same; it is measured much less.

What you have not yet understood is that the amount of change in the length of the boxcar due to your "length contraction", is equal to the change in distance between the source and the observer per second (caused by the change in relative speed), divided by the number of boxcars that now pass you in one second.

It may help you to see my logic by viewing the train while it is not moving (relative to the ground).
If the observer is also not moving (relative to the ground), then the observer will measure the frequency to equal zero, since no boxcars are passing him.

If the observer travels towards the train at some constant speed, then the observer will measure the frequency to equal the number of boxcars he passes in one second. The distance he has traveled per second, causes the frequency.

Multiplying the frequency by the length of the boxcar will equal the observer’s speed towards the train.
If the observer knew his speed (relative to the ground), he could divide it by the frequency and get the length of the boxcar.
Do you see how the observer’s speed causes the frequency and speed to change but not the length?
The frequency equals the distance the observer has traveled (relative to the ground) in one second, divided by the length of the boxcar.

Now if the train starts moving at some constant speed (relative to the ground) towards the observer, the observer will measure an increase in frequency equal to the distance the train travels (relative to the ground) in one second, divided by the length of the boxcar.

The relative frequency that the observer now measures is equal to the sum of the frequency created by the distance the observer has traveled (relative to the ground) towards the train in one second, added to the frequency created by the distance the train has traveled (relative to the ground) towards the observer in one second.

In a confusing but simple statement… The relative frequency equals the number of boxcars that the observer passes in one second, added to the number of boxcars that pass the observer in one second.

When calculating the length of the boxcar using the relative frequency, it must be divided into the sum of, the distance the observer has traveled (relative to the ground) in one second, added to the distance the train has traveled (relative to the ground) in one second.

The reason we measure a change in length is because the distance the observer has traveled (relative to the ground or the source) is never included.

The methods currently used to measure or calculate the relative speed of light were created to match Einstein’s two postulates. Einstein stated his postulates then created the math to match it. That is why current measurements and SR calculations used to find the relative speed of light will always equal the speed of light. For example see post #14 and post #141.

And when you reach exactly light speed (not possible for trains), the relative speed becomes constant, wavelength and frequency becomes variable [for light] *

So is it just that you don't buy length contraction? What about time dilation?

I think you made a typo above, SR shows that the wavelength and frequency are always inversely proportionate at any speed, which is why the speed of light is constant.

I do not believe in length contraction or time dilation. Both are tools used to keep the speed the same in order to validate Einstein’s two postulates. If you have the time, all my ideas are described in my first post.

swansont

Jun25-04, 03:17 PM

x2 and x1 are specific spots on the highway.

x1 = Location of car on the highway at time of acceleration.

x2 = Location of car on the highway at time of detection.

I'm not sure what point of view you are talking about, since the locations on the highway are the same for everyone, we could mark them with a flag at the time of measurement.

I also don't know what transformation you're referring to, if you do change the distance then you must equally change the time, else the answer will vary. SR equations are designed to always give the same answer; they were created off from Einstein's two postulates. The idea came first, then the math, that is why the math always proves the idea.

x1 and x2 are in a reference frame of an observer that is stationary with respect to the ground. If he wants to measure the relative speed between me and the car, he needs to know where I am at t1 -call that x3. Then the relevant distance is x1-x3. But I don't think that's the measurement you were describing.

I think that the math came first, actually, with Maxwell's equations and the Lorentz transformation.

swansont

Jun25-04, 03:19 PM

I do not believe in length contraction or time dilation. Both are tools used to keep the speed the same in order to validate Einstein’s two postulates.

But moving clocks do indeed run according to relativity, as witness by GPS and other spaceborne clocks.

wespe

Jun25-04, 04:31 PM

It may help you to see my logic by viewing the train while it is not moving (relative to the ground).
If the observer is also not moving (relative to the ground), then the observer will measure the frequency to equal zero, since no boxcars are passing him.

OK
relative speed=0
length of the train=100 km
measured frequency=0

Now change relative speed to 0.5c=150,000 km/sec
gamma=1.16
Due to length contraction, measured length will now be 100/gamma=86 km

Measured frequency will be = relative speed/measured length=1744 Hz

What you have not yet understood is that the amount of change in the length of the boxcar due to your "length contraction",

That is 100-86=14 km

is equal to the change in distance between the source and the observer per second (caused by the change in relative speed),

That is 150,000 km

divided by the number of boxcars that now pass you in one second.

That is 150,000 km /1744= 86 km

86 <> 14 therefore your statement was wrong.

Please clear this up before we can go further.

grounded

Jun25-04, 09:10 PM

86 <> 14 therefore your statement was wrong.

I actually predicted a change of 50 km since my observer would measure 1500 Hz, but either way, you are right, and I am wrong.

Accounting for the distance the observer has traveled relative to the source, does not account for or equal the change in length predicted by SR.

The focus of my paper was to point out that the scale of an oscilloscope or an interferometer must account for the distance traveled by the observer in order to accurately measure the light. If the observer’s distance is not accounted for, the wavelength will change, and the speed will remain constant. This is a fact and you should agree with it.

My error was to assume that this type of error was equal to, or related to the change predicted by SR. If the observers distance is not included, than at half the speed of light, an observer would measure the length to be half what it originally was. Clearly this is not what SR predicts.

My measurements come straight from the observer approaching the train. If the observer is traveling towards the train at 150,000 km per second, then he will pass 1500 individual 100km trains per second, relative to himself, else he would know he wasn't traveling 150,000 km per second.

After working through your example I realized that your measurements come from the perspective of an observer watching another observer who is approaching the train. The train and the observer traveling towards the train are in the moving frame that is being contracted by the Lorentz Transformation relative to the observer watching them.

Is that correct?

If this is so, it would explain why it could not be measured by an oscilloscope or an interferometer. You can’t use an oscilloscope to measure the length that an object would appear (http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/tdil.html#c1) to be to an observer viewing the object in a moving frame, it can only be calculated.

Right?

wespe

Jun25-04, 09:55 PM

..Clearly this is not what SR predicts.
I'm glad we found the source of the disagreement. Honestly, I don't want to screw this up, I too get confused sometimes, but your statements below indicate there is more misunderstanding.

My measurements come straight from the observer approaching the train.
So were mine. I considered only a train and one observer. The measurements/calculations were the observer's.

If the observer is traveling towards the train at 150,000 km per second, then he will pass 1500 individual 100km trains per second, relative to himself, else he would know he wasn't traveling 150,000 km per second.
Actually, in the example, he will pass 1744 individual 86km trains per second. The length contraction is not an illusion, it is real for the observer. That is, if the observer was a sitting in a 100km train, and if compared the passing train next to his train, he would find the passing train really shorter and contracted to 86km. What's more, the contraction is mutual: the passing train would claim it was the other train that became shorter.

After working through your example I realized that your measurements come from the perspective of an observer watching another observer who is approaching the train. The train and the observer traveling towards the train are in the moving frame that is being contracted by the Lorentz Transformation relative to the observer watching them.
Is that correct?

As noted above, a second observer was not present. But if you mean a second observer stationary wrt the first observer, his perspective would be the same as the first observer, since they are in the same frame of reference.

You can’t use an oscilloscope to measure the length that an object would appear (http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/tdil.html#c1) to be to an observer viewing the object in a moving frame, it can only be calculated.
Right?

If you mean: the observer can't directly measure 100km., yes. He measures 86km, it's real. But also knowing the relative speed, he can calculate 100km by multiplying the measured 86km by gamma.

geistkiesel

Jun26-04, 06:56 AM

But moving clocks do indeed run according to relativity, as witness by GPS and other spaceborne clocks.
Swansont, you are wrong. Of course the measurements will run slower as the observer has not used her own velocity wrt to the velocity of the source of the photons. The error "the speed of light is always measured as c in all inertial frames" and will always be reflected by the error in failure to include the observer's velocity.

Read grounded's posts again, until you understand them and then attack those posts on their own merits. Very diffilcult isn't it, to not have to fall back on SR dogma?

David

Jun26-04, 09:20 AM

If I may hazard a guess, the reason you are banned from the relativity forums because your topic is Einstein, not relativity. Worse, you have this nasty habit of hijacking threads to start this discussion, instead of giving it its own thread.

Not so.

The “relativity” threads are Einstein-worship threads, for GR and SR. The moderators don’t allow anyone to point out that SR is wrong and contains major errors, some of which Einstein corrected later.

If they want to talk about modern real relativity theories that actually work, then I’ve got no gripe or complaint.

But guys like Russ are SR believers and he refuses to recognize any errors in that 1905 paper, even though Einstein wrote other papers later correcting SR theory. Those are papers that Russ has not read. I can't even quote from Einstein's later correction papers, even if Einstein himself made changes in SR theory later, because guys like Russ believe completely in the original 1905 SR theory.

That’s why I was banned from the “relativity” threads, because they are SR and GR Einstein relativity threads designed to promote only Einstein’s old, obsolete, and out of date SR and GR versions of relativity.

grounded

Jun26-04, 11:24 AM

If you mean: the observer can't directly measure 100km., yes. He measures 86km, it's real. But also knowing the relative speed, he can calculate 100km by multiplying the measured 86km by gamma.

I thought the observer couldn’t measure a change since his measuring stick has also contracted?
Quoted from the Microsoft Encarta Encyclopedia, (I hope this isn’t illegal):
In the 1890s FitzGerald and Lorentz advanced the hypothesis that when any object moves through space, its length in the direction of its motion is altered by the factor beta. The negative result of the Michelson-Morley experiment was explained by the assumption that the light actually traversed a shorter distance in the same time (that is, moved more slowly), but that this effect was masked because the distance was measured of necessity by some mechanical device which also underwent the same shortening, just as when an object 2 m long is measured with a 3-m tape measure which has shrunk to 2 m, the object will appear to be 3 m in length. Thus, in the Michelson-Morley experiment, the distance which light traveled in 1 sec appeared to be 300,000 km (186,000 mi) regardless of how fast the light actually traveled.
Microsoft® Encarta® Reference Library 2002. © 1993-2001 Microsoft Corporation. All rights reserved.

This is how I see it, what is your opinion?

The Michelson-Morley experiment was conducted to measure the resistance light encountered when traveling against the hypothesized ether.

No matter how or when they did the test, they couldn’t measure any resistance (ether).

Not wanting to let go of the ether, Lorentz hypothesized that the ether does exist, you just can’t see, feel, or measure it.

The Lorentz contraction explains why Michelson-Morley could not measure the resistance. The effect was masked because the distance was measured of necessity by some mechanical device that also underwent the same shortening.

Einstein took it another step and said the speed of light is the same for all observers. If the speed of light is constant, then so is Maxwell's equations. Michelson-Morley couldn’t measure a change in speed because the speed of light was constant and it was lengths and time that must be changing, which is why we couldn't measure it.

To me, it seems like the Michelson-Morley experiment proves that relative to the source, a ray of light will travel in any direction, away from the source, at the same speed. They were expecting it to be slower in the direction that was against the flow of the ether, which was the reason for the experiment. When they couldn't measure it, they had to explain why.

When they could not measure the effects of the ether, they said, the ether does exist, you just can’t measure it.

According to classical physics, one of the two observers was at rest, and the other made an error in measurement because of the Lorentz-FitzGerald contraction of his apparatus
Microsoft® Encarta® Reference Library 2002. © 1993-2001 Microsoft Corporation. All rights reserved.

I have to assume by the above, that they still believed there is a resistance to light, it just can’t be measured. Another words, they still refuse to believe the results of the Michelson-Morley experiment.

According to Einstein, both observers had an equal right to consider themselves at rest, and neither had made any error in measurement. The equations for this transformation, known as the Lorentz transformation equations, were adopted by Einstein, but he gave them an entirely new interpretation. The speed of light is invariant in any such transformation.
Microsoft® Encarta® Reference Library 2002. © 1993-2001 Microsoft Corporation. All rights reserved.

I believe Einstein meant the "both observers" to be, one traveling with the ether, and one traveling against the ether. Another words, one of the observers was measuring the light that was reflected and sent against the ether flow in the Michelson-Morley experiment, and the other observer was measuring the light that went with the ether flow.

In the above quote, it seems like Einstein too refuses to believe the results of the Michelson-Morley experiment. I am not sure if Einstein believes that the constant speed of light causes the Lorentz contraction, or if the Lorentz contraction causes the speed of light to remain constant. In either case, to prove that what Michelson-Morley measured was wrong, a contraction had to be applied that could not be measured by the observer. Both Einstein and Lorentz seem to be giving us a theory for why what we measured in the Michelson-Morley experiment is wrong.

To me it seems like Einstein is stating that SR applies to the ether and the source. No matter how fast or what direction the source moves through the ether, the speed at which light travels away from the source will remain constant whether moving with or against the ether flow. SR predicts the change we couldn't measure with the Michelson-Morley experiment. Is that right? SR says that when the light reflects off the mirror in the interferometer, and starts traveling against the ether flow, the reason we can't measure it is because the lengths and time have changed. Is that right?

The Michelson-Morley experiment did not have two observers moving relative to each other. The source of light was at rest with the interferometer, the light traveled from the source, then reflected off a mirror as to travel against the ether flow. The motion of that ray of light is what was assumed to be moving relative to the ether. The relative motion is between the source and the ether, what other relative motion is there?

If a ray of light is moving through space at 300,000 km/sec (186,000 mi/sec), and an observer is moving in the same direction at 29 km/sec (18 mi/sec), then the light should move past the observer at the rate of 299,971 km/sec (185,982 mi/sec); if the observer is moving in the opposite direction, the light should move past the observer at 300,029 km/sec (186,018 mi/sec). It was this difference that the Michelson-Morley experiment failed to detect.
Microsoft® Encarta® Reference Library 2002. © 1993-2001 Microsoft Corporation. All rights reserved.

The Michelson-Morley experiment failed to detect the added velocity of the observer (as worded above) because the observer was not moving relative to the source of the light, the ray of light was moving relative to the ether flow. In the above quote, they are implying the observer is moving relative to the source. It should read like this:

If a ray of light is moving through space in the direction of the ether flow at 300,000 km/sec (186,000 mi/sec), and an observer is moving in the same direction as the ether flow at 29 km/sec (18 mi/sec), then the light should move past the observer at the rate of 299,971 km/sec (185,982 mi/sec); if the observer is moving in the opposite direction of the ether flow, the light should move past the observer at 300,029 km/sec (186,018 mi/sec). It was this difference that the Michelson-Morley experiment failed to detect.

How does the Michelson-Morley experiment prove what an observer (the observer) will measure while traveling towards the source?
Is SR just another theory used to explain the null results of the Michelson-Morley experiment?

The questions are in blue, thanks for helping!

wespe

Jun26-04, 12:53 PM

I thought the observer couldn’t measure a change since his measuring stick has also contracted?

True, the observer can't measure any change in his own mesauring stick (or better, there isn't any change according to him). But he does measure the measuring sticks in other frames shorter than his measuring stick. "his measuring stick has also contracted" is from the perspective of other frames.

Imagine you and I are holding 1 meter measuring sticks in the direction of each other. We both agree when we are at rest wrt each other. Then let us approach at a speed. I would see your meter contracted, and you would see my meter contracted. We would both think our [own] meters didn't change [it's always the other's meter that changed] and we would not agree on whose meter is shorter. But from a third person's perspective, both of our sticks might have been contracted. Everyone is correct according to oneself.

"The negative result of the Michelson-Morley experiment was explained by the assumption that the light actually traversed a shorter distance in the same time".
This is how I see it, what is your opinion?

Well, this explanation is from aether's perspective. Since we don't think aether exists anymore, it doesn't look like a good explanation now.

http://scienceworld.wolfram.com/physics/Michelson-MorleyExperiment.html
At the end of the page:"Einstein's idea of space-time contraction replaced Lorentz's interpretation "

So, Lorentz thought things contracted from aether's perspective. Now we say things (excluding oneself) contract from everyone's own perspective . Note that this also includes aether, so if you want to assume aether exists, things would contract from its perspective too. It is just that such a preferred frame cannot be distinguished from any other frame, so it was dismissed.

I think I have said above all that I can. Please let me know if something seems unclear.

edit: I see you questions in blue, maybe edited for more. I'm not ignoring them. Just wanted to make sure above points are clear first.

grounded

Jun26-04, 02:09 PM

When I said "This is how I see it, what is your opinion?", I meant the writing below, not the writing above.

grounded

Jun26-04, 02:19 PM

So, Lorentz thought things contracted from aether's perspective. Now we say things (excluding oneself) contract from everyone's own perspective.

Before we go on, do you agree that the Lorentz contraction was created to explain why we DID NOT measure a change in the speed of light when it traveled against the aether during the Michelson-Morley experiment?

I do know that Einstein replaced the Lorentz contraction, but wasn't it still used to explain why we DID NOT measure a change in the speed of light when it traveled against the aether?

ram1024

Jun26-04, 02:32 PM

he's saying there is no aether.

contraction was made up to satisfy condition of relative light speed. not aether

Tom Mattson

Jun26-04, 03:47 PM

Originally posted by geistkeisel
Tom, excuse me if i've asked this before, but show me Grounded's math in 19th Century physics, AND that 19th century physics is passe because it is so old.

You did ask, and I did answer. Whether or not he realizes it, he is using the Galilean velocity transformation to determine the speed of the light emitted by a moving source. And it’s not “passe because it is so old”, it is passe because it is wrong.

Tom, Grounded showed by example the necessity of including the observers relative velocity less a mistake be made in the measurement of the length of the cars (wave length of light).

No, he didn’t. All he showed is that he doesn’t understand why Galilean relativity fails.

The SR system creates a mistake in measuremment and needed to create SR to explain the error.

No, it doesn’t. SR has nothing to do with how measurements are made. SR is a theory, not an experimental procedure. It just so happens that when you do make a measurement, the theory of SR gets it right, and the theory of Galilean relativity gets it wrong.

How many times can you echo "the vast amount of experimental results" describing your collective error? The experiments that prove time dilation, contraction of matter, loss of simultaneity?

How long can you keep it up before the echo wears thin?

I’ll keep it up until stubborn knuckleheads such as yourself keep polluting our site with anti-scientific nonsense.

Tom, lifting the weight of SR will be a relief, a huge relief.

How, precisely, will abandoning an accurate theory of the physical world be any relief to me as a physicist?

They're are errors Tom, great big huge errors.

And how would you even know? You've already confessed a refusal to even learn the theory.

Tom Mattson

Jun26-04, 03:48 PM

Originally posted by grounded
Tom, you say it is not "built in", but consider the following;

Can you calculate the relative velocity between a moving car and yourself by measuring the following?

Event 1: Car Accelerated (Assume instantaneous acceleration to 60 Miles Per Hour)
x1=Location of car on x-axis at time t1.
t1=Time of acceleration.

Event 2: Car Detected
x2=Location of car on x-axis at time t2.
t2=Time of detection.

The speed of the car relative to you is then:

v=(x2-x1)/(t2-t1).

Yes, that’s exactly right.

Can you alter the relative speed of the car while using this formula?

Sure. The car can accelerate, or I can, or we both can.

It’s not that they (edit: trains and light) behave differently, it’s that we calculate them differently.

You are half right, and half wrong here. It is true that the speed of trains and the speed of light don’t “behave differently”. But you are wrong in saying that we calculate them differently. Both the speed of trains and the speed of light are calculated according to the formula I gave. Furthermore, they both are calculated from a third party perspective using the SR velocity addition law. But for low speeds, the Galilean velocity addition law gives a good enough approximation, so that we apply it to trains for simplicity’s sake. But one should not be fooled into thinking that we can use that velocity addition law for light.

If you measure the train like we measure the light, then the speed of the train will never change.

Incorrect. If either myself or the train accelerates, then the measured (and calculated) speed will change.

If you measure the light like we measure the train, then the length of the boxcar will never change.

Not so. The length of the boxcar will be contracted. I’m sorry you don’t accept it, but it is a fact.

ram1024

Jun26-04, 03:51 PM

you guys always talk about "the data" as if it proves the theory. yet surprisingly no one brings forth the actual data.

vast amounts of data, yet not a single bit of it brought into play. are you sure there's vast amounts of it?

Tom Mattson

Jun26-04, 03:58 PM

What you have not yet understood is that the amount of change in the length of the boxcar due to your "length contraction", is equal to the change in distance between the source and the observer per second (caused by the change in relative speed), divided by the number of boxcars that now pass you in one second.

No, it isn't. The length of the boxcar is contracted according to the following formula:

L=L0/γ

That is not the simple ratio of speed to boxcars-per-second.

The reason we measure a change in length is because the distance the observer has traveled (relative to the ground or the source) is never included.

You are still confusing measurements with calculations. When you measure a length contraction, a time dilation, or a relative change in wavelength, then that's what its value is. Period. If you modifiy it with a calculation, then it is just that: a calculation, not a measurement.

The methods currently used to measure or calculate the relative speed of light were created to match Einstein’s two postulates.

Einstein stated his postulates then created the math to match it. That is why current measurements and SR calculations used to find the relative speed of light will always equal the speed of light. For example see post #14 and post #141.

I can't believe you are still preaching this. All you have to do is measure the time and place of emission and the time and place of detection. That method of mearsurement does not guarantee the SR result on simple a priori grounds.

I do not believe in length contraction or time dilation. Both are tools used to keep the speed the same in order to validate Einstein’s two postulates. If you have the time, all my ideas are described in my first post.

You are also wrong about this. Length contraction and time dilation aren't "tools used to keep the speed the same" in various inertial frames. Length contraction and time dilation are the logical consequences of that postulate. In other words, they are derived from it.

Tom Mattson

Jun26-04, 04:01 PM

you guys always talk about "the data" as if it proves the theory. yet surprisingly no one brings forth the actual data.

That's a good point. The reason we don't get to talk about the data is that we are so bogged down on stupid thought experiments.

vast amounts of data, yet not a single bit of it brought into play. are you sure there's vast amounts of it?

There is. I am going to dig out a bunch of papers I have packed in a box and prepare something. It's about time we get back to the real world.

ram1024

Jun26-04, 04:13 PM

make sure you include the data about scientists getting light to travel 100 times faster than normal calculated speeds using cold caesium chamber and group resonance beams of light.

according to einstein's "time" that speed makes the pulses received out of the other end of the chamber happen BEFORE the pulses are introduced to the entrance chamber.

the result? using light to measure instant time is a bad idea. DERIVING time from light is a better idea. using synchronicity to define time is the best idea.

looking forward to what you can come up with :smile:

Tom Mattson

Jun26-04, 04:27 PM

make sure you include the data about scientists getting light to travel 100 times faster than normal calculated speeds using cold caesium chamber and group resonance beams of light.

I will indeed track down that paper. In the mean time, please do read what the actual experimenters had to say about it:

http://www.cnn.com/2000/fyi/news/08/21/speed.of.light/#3

according to einstein's "time" that speed makes the pulses received out of the other end of the chamber happen BEFORE the pulses are introduced to the entrance chamber.

That is indeed the prediction of SR. Now the question is, were the photons that came out of the chamber the same as those that went in?

the result? using light to measure instant time is a bad idea. DERIVING time from light is a better idea. using synchronicity to define time is the best idea.

You believe this because you still do not understand the necessity of SR for electrodynamics.

ram1024

Jun26-04, 04:57 PM

does it matter that the light wasn't the same particles as what went in? not in the slightest.

think of a hose filled with water. you start forcing water into one end and water starts coming out the other side. this was water already in the hose, not water you put in, your water doesn't come out till later

but what IS accomplished is the speed of information transfer IS faster than light speed. the modality of synchronizing events "by light" is trumped by this new "speed". if something CAN be faster than light, what's to say something can't be even faster than THAT thing. which was why i was saying deriving instances of time is a good way to handle things, using known speeds of light is a good thing. but using light as a governor of when things happen in "time" is not so good, as things travelling faster than it "information" will go back in time, which is Unpossible <Ralph Wiggum>

Tom Mattson

Jun26-04, 05:01 PM

does it matter that the light wasn't the same particles as what went in? not in the slightest.

Of course it matters!

Given permission by the city, I could rig up a series of streetlights to turn on--one at a time--in such a way that it appears that there is one light that is moving faster than 'c', when nothing is actually moving at that speed.

ram1024

Jun26-04, 05:08 PM

yes, but you couldn't rig it to change the order of events as they appear according to viewing "by light" as "time" as they have done in the lab.

there's no prediction or preplanning. the photons exit the chamber about 300 times sooner than they should have using direct light beam transmission

that's called "faster than light" in any definition of the term :D

doesn't matter than it wasn't LIGHT moving faster than LIGHT. INFORMATION did.

Tom Mattson

Jun26-04, 05:14 PM

doesn't matter than it wasn't LIGHT moving faster than LIGHT. INFORMATION did.

But the experimenters themselves never claimed that they could send information faster than light. How could you possibly claim to know it?

ram1024

Jun26-04, 05:18 PM

Tom Mattson

Jun26-04, 05:27 PM

there was an event on one side and a reaction on the other side, a reaction that happened 300 times faster than SHOULD have happened using light speed as a measure.

think binary. a bit of information "1" was sent into the tube. a bit of information "1" was received 300 times faster than it would have been using direct light transmission over the same distance.

THAT is why.

The experimenters also reported that part of the pulse was detected at the exit before it was detected at the entrance, and yet Wang (the head scientist) specifically denies that he could use the effect to send information back in time. Furthermore, every analyst of this experiment has concluded that information was not sent faster than light. Aren't you even the least bit curious as to why? Don't you feel compelled to consult the literature on the experiment? Doesn't the first hand testimony of the people who designed the experiment and witnessed the effect carry any weight with you? Or are you satisfied with your simplistic explanation based on only a partial knowledge of what actually occured in that lab?

ram1024

Jun26-04, 05:38 PM

Aren't you even the least bit curious as to why?

i've already read about "why"

they're coming to the wrong conclusion trying to intercept the whole pulse,

ANYTHING coming out the other end can be taken as that "bit" of data.

align 4 tubes <arbitrary number> and transmit using all 4, by moving to another "tube" while waiting for the one you just used to complete in rotation you can transmit data AT LEAST 4 times faster than the speed of light.

with 300 tubes you could utilize the full capabilities of this speed. course the "switching" would have to be damn complex for that ;D

in any case i'm sure they adequately realize the potential of their results, but don't want to "give" any of the technology away if they can help it.

Tom Mattson

Jun26-04, 06:00 PM

i've already read about "why"

Somehow, I don't think you have read the articles that appeared in the research journals.

they're coming to the wrong conclusion trying to intercept the whole pulse,

Well, you should email them right away!

Here's their Science director's webpage:

http://www.neci.nj.nec.com/homepages/chadi

ANYTHING coming out the other end can be taken as that "bit" of data.

But it is not the case that anything coming out can be seen as intelligible information.

in any case i'm sure they adequately realize the potential of their results, but don't want to "give" any of the technology away if they can help it.

What they want is to make a name for themselves, not to get patents. Scientists publish their results freely in journals such as Physical Review Letters. These scientists are no exception.

wespe

Jun26-04, 06:09 PM

Before we go on, do you agree that the Lorentz contraction was created to explain why we DID NOT measure a change in the speed of light when it traveled against the aether during the Michelson-Morley experiment?

Yes. The contraction would cancel the effect of aether resistance.

I do know that Einstein replaced the Lorentz contraction, but wasn't it still used to explain why we DID NOT measure a change in the speed of light when it traveled against the aether?

Well, since aether was dismissed, it isn't currently used to expain anything about aether. As I wrote before, if you want to assume aether exists, you can treat it like any other frame of reference, and the length contraction explanation would appy.

However, there's another issue. Suppose you simply explain MMX result with length contraction. There is no need to abandon absolute space, and all observers could agree on how their lengths would compare. But according to SR, observers will not agree. I think that's an important point.

ram1024

Jun26-04, 06:09 PM

wespe

Jun26-04, 06:30 PM

No, it isn't. The length of the boxcar is contracted according to the following formula:

L=L0/γ

That is not the simple ratio of speed to boxcars-per-second.
....

Tom,
in post #186, Grounded already found out his assumption did not match with SR's predictions. It would help if you could help me answer his questions after that post because I'm no expert and you seem to be. Thank you.

Tom Mattson

Jun26-04, 06:39 PM

you don't seem to be understanding me.

ANYTHING coming out the other end is "Data"

it either IS or ISN'T, 1 or 0. this is the principle behind binary computing.

the data coming out the other side doesn't need to do anything other than exist :confused:

I understand you just fine. But what you aren't understanding is that in order for "information" to travel from one spacetime point to another, the carrier of information has to do more than just "exist". It has to be causally connected to the source so that something intelligble can be communicated. If the people who did the experiment do not claim that they could send information faster than light, then who are you to claim that they can?

Do yourself a favor: Read up on this.

ram1024

Jun26-04, 06:51 PM

the tube IS connected the receiving end to the source. i have no idea what you're talking about but if i want to transmit "Hi Mom" in binary 300 times faster than the speed of light to the target location, i take 6 bytes of data (8 bits per byte) and through the system pipe of 48 tubes this "information" is transfered to the other end 300 times faster than light speed would reach.

thus if the computer on MY end was capable of deciphering those 48 bits and displaying them instantly, i could have them on MY screen before i would see them on YOUR screen, if you flashed them on YOUR screen AND transmitted them through the tube system at the same time.

:grumpy:

Hurkyl

Jun26-04, 07:00 PM

The problem is that the experimental setup is transmitting "Hi Mom" subluminally.

The "magic" is that the entry to the tube delays acknowledging the transmission until just before the exit receives it. This generates the illusion that the information went from the entry to the exit superluminally.

Tom Mattson

Jun26-04, 07:16 PM

the tube IS connected the receiving end to the source.

I know that. Just like in my streetlight example, the lights are connected to my switch. That doesn't mean I can send information faster than light with them.

i have no idea what you're talking about but if i want to transmit "Hi Mom" in binary 300 times faster than the speed of light to the target location, i take 6 bytes of data (8 bits per byte) and through the system pipe of 48 tubes this "information" is transfered to the other end 300 times faster than light speed would reach.

thus if the computer on MY end was capable of deciphering those 48 bits and displaying them instantly, i could have them on MY screen before i would see them on YOUR screen, if you flashed them on YOUR screen AND transmitted them through the tube system at the same time.

LOL, well one thing is clear: You are certainly content to make a few simplifying assumptions when the problem gets difficult! The truth is that you have no idea of what your computer screen would say. You are just guessing that your machine will be able to interpret the pulse. The real scientists who did the real experiment in a real laboratory, on the other hand, disagree.

Why are you being so stubborn about this? The experimenters themselves said that what you have proposed cannot be done. Why don't you listen to them?

Here's an excerpt from a news report in which one of the experimenters was quoted.

From http://www.msnbc.com/news/435007.asp?cp1=1

"All this might make it sound as if the NEC researchers found a way to send a message at speeds faster than 186,000 miles a second — which could theoretically open the way for a sort of time travel. But the researchers contend that is not the case. Their experiment dealt with smooth changes in a pulse, and “a smooth function cannot carry information,” Dogariu said. Sending information — for example, the flashes of a laser semaphore — would require sharper variations in frequency that could not be processed in the type of finely tuned atom chamber used by the NEC researchers.

Color added by me, for emphasis.

ram1024

Jun26-04, 07:33 PM

i KNOW that.

why do you think i said 48 chambers? because each ONE would be transmitting one BIT of information (either ON or OFF) to the destination.

}}| | | || | | || | ||| || | | | || || | || {{ - light in tubes
}}100010101101010110101110110101001001101100100011 0{{ - interpreted data

assume that all that crap up there translates to "hi mom" a string of 6 character expressed in binary.

each BIT of information can be transmitted to the other end of the tube 300 times faster than light speed.

it is instantly processed by my computer and displayed on the screen (assume so to make a point).

if you displayed the words "HI MOM" on your screen AND sent the data down the tubes AT THE SAME TIME (co-local simultaneity DOES exist) then i would receive those 48 bits of data FASTER than looking over and waiting for the light from your screen to register "HI MOM" to my eyes.

we're talking 62 billionths of a second though for a 50 ft pipe of caesium, so the real result is "big deal?"

but what this DOES say is using light for simultaneity DOES fail for transmission of information at superluminal speeds. in essense, if light is your limiter for this situation then the message DOES come out on the receiving end BEFORE it was sent in, calculated with light simultaneity

Tom Mattson

Jun26-04, 07:37 PM

i KNOW that.

You say that, but then you steamroll right over the troublesome part of the problem.

Right here:

it is instantly processed by my computer and displayed on the screen (assume so to make a point).

!!!

That's exactly the problem! You can't just assume that this can be done.

Again, I ask: Why are you being so stubborn about this? Why don't you believe the people who were there, when they tell you that this sort of pulse cannot be used to do what you say it can? What makes you think you know better than them, without ever having done any work in this field?

ram1024

Jun26-04, 08:46 PM

ram1024

Jun26-04, 08:50 PM

What makes you think you know better than them, without ever having done any work in this field?

you're just unwilling to conceed towards superluminal information transfer. logically if you think about it, and you know anything about information transmission you would KNOW what i'm saying is reasonable.

they know it too since they work in the business. i'm pretty sure "it can't be done" is either fog to keep competition away from what they're going to pioneer as new technology OR their data is faulty and they have no idea what they're talking about (their experiment is a sham).

take whichever of those two conclusions makes you feel the safest... :D

geistkiesel

Jun26-04, 10:40 PM

True, the observer can't measure any change in his own mesauring stick (or better, there isn't any change according to him). But he does measure the measuring sticks in other frames shorter than his measuring stick. "his measuring stick has also contracted" is from the perspective of other frames.

Imagine you and I are holding 1 meter measuring sticks in the direction of each other. We both agree when we are at rest wrt each other. Then let us approach at a speed. I would see your meter contracted, and you would see my meter contracted. We would both think our [own] meters didn't change [it's always the other's meter that changed] and we would not agree on whose meter is shorter. But from a third person's perspective, both of our sticks might have been contracted. Everyone is correct according to oneself

I think there may be a contradiction here and that you may have erred slightly, Let us expand the situation. Two observers wih 1 meter rods are moving such that a stationary observer will see a length contraction to .9m on each rod and these observers are moving parallel and in the same direcion to each other. Clearly the rods would look the same to both observers, agreed?

Now we have the observers moving towad each other, but each is ignorant of he oher's presence. The grouind observer will will see a contraction to both rods to .9m each. Your statement that each observer would think the other's rod has changed and no agreement could be made, I Iassume you are placing each in the position of an effective stationary observer wrt the other. With a stationary observer noting changes, she still sees the rods shoren to .9c. But let us have the rods placed parallel and close to each other when they pass (or from an SR perspective when A passess B or B passes A) by each other.

It would be physically impossible for each of the moving obsevers to claim hat their rod was longer than the other. First their relaitive speed with respect to the stationary observer is the same, and hence the stationary observer keeps the books straight from his perspective.

However when passing next to each other there could be no disagreement between the observers as any disputes could be resolved with a simple inspection. So my question is what is the value, the wort, the utility of using assumed stationary frames when measuring relative velocity? The mathematics may allow you to do that and SR may allow you to do that, but there is the physical impossibility that the assumptions could ever be realized in practice, and then what of the assumed frame changes, i.e. to the rods?

The point is that making an assumption that an observer on a moving frame is stationary and the other moving, (and vice versus) just because the mathematics appears to alllow this kind of comparison is contradicted by physical law. Moving bodies do not enjoy the arbitrary luxury of starting and stopping at the will of an observer in that particlular frame, under any circumstances, yet this seems to be a common practice among SR theorist describing reality..

Just to overkill a tad. If one rod is shortened to .9m and the other to .5m as measured by a third observer then each could claim, re SR, that the other rod had shortened to .4m? How long would this assumption be demonstrably true, if ever? Especially when they pass next to each other and see the differences? Which they would see if their eyes were a few wave lengths from herods as they slid past, agreed?

If SR maintains this posture then it would have to conclude, as you said in your post, that each sees the other as shortening, but can the rod that is .9m wrt the stationary observer appear as .4m wrt to the other moving observer? Especially at the instant the rods were located next to each other, clearly visible to both? Couldn't each observer jump in the other's shoes and see the rods from the other's perspective? Apparently SR says you can. Each observer with the mere mental decision can place themselves in the other's position or themsleves at rest, or at any velocity compatible with the observed velocity as measured by the stationary observer?

Tom Mattson

Jun27-04, 01:02 AM

the crux of the argument is information being transmitted at speeds faster than can be accomplished by light.

i was never arguing you that it's not feasible to do so because we lack the computing power to process that information at those speeds.

not once :D

Guess what? I never mentioned computing power either. Not once!

The problem at hand is not that we lack the technology to interpret the signal, the problem is that the signal that can break the lightspeed barrier is physically incapable of carrying information.

you're just unwilling to conceed towards superluminal information transfer. logically if you think about it, and you know anything about information transmission you would KNOW what i'm saying is reasonable.

I do know a thing or two about information transfer, and I "KNOW" that what you are saying is just wishful thinking.

they know it too since they work in the business.

Oh, they know it too, do they? Is that why they are saying it can't be done? That's a strange way of saying that they agree with you.

i'm pretty sure "it can't be done" is either fog to keep competition away from what they're going to pioneer as new technology OR their data is faulty and they have no idea what they're talking about (their experiment is a sham).

take whichever of those two conclusions makes you feel the safest... :D

I'm not going to take either one of your options, because they are both idiotic.

Tell you what. You construct a superluminal communications system and send me a message at 300 times the speed of light. Go ahead and try it, if you're so sure. Send me a message at 300 times the speed of light, and I'll believe you.

Waiting....

wespe

Jun27-04, 01:08 AM

Let us expand the situation. Two observers wih 1 meter rods are moving such that a stationary observer will see a length contraction to .9m on each rod and these observers are moving parallel and in the same direcion to each other. Clearly the rods would look the same to both observers, agreed?
When they are moving like that, they are stationary wrt each other. Agreed.

Now we have the observers moving towad each other, but each is ignorant of he oher's presence. The grouind observer will will see a contraction to both rods to .9m each. Your statement that each observer would think the other's rod has changed and no agreement could be made, I Iassume you are placing each in the position of an effective stationary observer wrt the other.

I did not place them in somewhere else

With a stationary observer noting changes, she still sees the rods shoren to .9c. But let us have the rods placed parallel and close to each other when they pass (or from an SR perspective when A passess B or B passes A) by each other. It would be physically impossible for each of the moving obsevers to claim hat their rod was longer than the other.
However when passing next to each other there could be no disagreement between the observers as any disputes could be resolved with a simple inspection.

It is possible due to relative simultaneity. The ends of both rods will not meet at the same time according to both frames. The disagreement in simultaneity in turn makes both see the other's rod shorter than his own.

First their relaitive speed with respect to the stationary observer is the same, and hence the stationary observer keeps the books straight from his perspective.

So my question is what is the value, the wort, the utility of using assumed stationary frames when measuring relative velocity?
"using assumed stationary frames when measuring relative velocity". I don't follow.

The mathematics may allow you to do that and SR may allow you to do that, but there is the physical impossibility that the assumptions could ever be realized in practice, and then what of the assumed frame changes, i.e. to the rods?
In reality, I think length contraction is supported by muon decay observations.

The point is that making an assumption that an observer on a moving frame is stationary and the other moving, (and vice versus) just because the mathematics appears to alllow this kind of comparison is contradicted by physical law. Moving bodies do not enjoy the arbitrary luxury of starting and stopping at the will of an observer in that particlular frame, under any circumstances, yet this seems to be a common practice among SR theorist describing reality..

The point is, you can't detect which one is really stationary, can you? Just because something is bigger doesn't mean it is more stationary. Without any support that aether exists, it is meaningless to say something is really stationary.

Just to overkill a tad. If one rod is shortened to .9m and the other to .5m as measured by a third observer then each could claim, re SR, that the other rod had shortened to .4m?
It depends on relative speeds. I don't think that simple calculation will do to find relative length. Check the gamma formula. L=L0/gamma

How long would this assumption be demonstrably true, if ever? Especially when they pass next to each other and see the differences? Which they would see if their eyes were a few wave lengths from herods as they slid past, agreed?
To understand it clearly, assume the rods are very very long. You can't see both ends at the same time, how will you compare them as they pass next to each other? You must place synchronized clocks on each end and make two simultaneous measurements. That's is where relative simultaneity kicks in.

If SR maintains this posture then it would have to conclude, as you said in your post, that each sees the other as shortening,
yes

any velocity compatible with the observed velocity[/I] as measured by the stationary observer?

Well they can calculate what each other measures. But SR predicts their own measurements will be like that: each see own rod normal and the other's shorter.

As I said numerous times, I'm no expert and I may have understood some things wrong, I'm just trying to help by my best. But why act like you are hearing what I claim the first time. Check out the usenet FAQ if you didn't already.
http://math.ucr.edu/home/baez/physics/
barn and pole paradox is especially relevant to this

geistkiesel

Jun27-04, 01:46 AM

[Tom - this is just an intejection for your consderation.

Frame to frame references’

When those describing some aspect of SR use the terms that “the moving frame1 can consider itself stationary and the moving frame2 as moving” I ask is this a legitimate dynamic in mathematical analysis?. From this we get assumptions that a moving train, for instance, can consider itself at rest and the platform as moving. Now we know that only trains actually move and the stationary platforms remain stationary. In fact it is a physical impossibility for the described assumption to ever be realized, despite the allowed freedom and even encouragement of mathematical models to exploit the frame referencing processes as described.

What is the physical justification for manipulating models in this manner?

Here is a general and generic problem; two moving observers with the same velocity are side by side with one-meter rods in each of their frames. A stationary observer sees the rods shortened to .9m each, which goes unrecognized by the moving observers. Now we have the observers moving toward each other with the same shortened rods as observed from a stationary observer. SR theory allows either frame to consider itself as stationary and, I assume, that the other’s rod is .8m. Each will perceive the other’s rods as shorter than their own. When the observes get next to each other and the rods are measurable, at least by comparison, it would seem ludicrous to allow both observers at this point to determine any of the rods as shorter than the other. Where is the cut off point? Where is the frame referencing assumption limited, if at all?

It appears to me that even the simplest example of one frame assuming a v = o posture, giving all velocity to another frame, or the inverse, and the consequential time dilation and frame shortening is nothing but a mathematical contrivance to have the observers determine which is shorter or longer at their singular decision.

I trust you can appreciate the seriousness of this item, which is one of many that minimize any enthusiasm from serious consideration of studying SR in depth. I believe you when you say SR will predict what ever you say. I will not be engaged in any discourse on what is or is not SR theory and what are its affects. I assume the truth of the matter and if I see an objection I will scrutinize that which I observe. You have seen my posts, I have seen yours, and it is about time we recognize that we aren’t going to change anyone’s mind easily. In fact minds don’t get changed in matters like these without conscious decisions being made.

Ram1024 made a good suggestion that we strive for some real experiments to conduct. If sufficient professional creativity is applied we can design the experiments in threads. I was considering the experiment you referenced where the speed of light c wrt to some gamma particles (if I recollect) moving at .99c was measured. . Assuming the validity of the experiment as run what could be adjusted to determine if any objections originating in the forum can be exploited such as Grounded’s added velocity scheme, or moving platforms radiating photons from A and B to M the midpoint etc.

It is going to get very dry when the enthusiasm begins to wear thin and only the diehards are still going at it.

geistkiesel

Jun27-04, 02:19 AM

When they are moving like that, they are stationary wrt each other. Agreed.

I did not place them in somewhere else

I only meant that one could say one or the other was moving or stationary at will.

It is possible due to relative simultaneity. The ends of both rods will not meet at the same time according to both frames. The disagreement in simultaneity in turn makes both see the other's rod shorter than his own..

If both fames are moving with velocity v wrt a stationary frame and they pass each other head on, must not the rods measure the same lengths? If the rods are 1/10 mm from each other and approximatey 1 meter long (meaning both obsevers can see the other's rod at the same time they see their own).. They have to see the same thing wouldn't they? Especially if the lengths were confirmed by a stationary observer. So what iof the efficacy of assuming one is moving the other stationary? And Where the observers make this determination?

In reality, I think length contraction is supported by muon decay observations.

i am not disputing SR experiments, I am simply trying to determine if the assumptions that either frame may consider itself as moving or stationary when the two frames are making measurments of each other's physical characteristics..

The point is, you can't detect which one is really stationary, can you? Just because something is bigger doesn't mean it is more stationary. Without any support that aether exists, it is meaningless to say something is really stationary.

Well an electron mocing at .99999c in a SLAC accleration experiment measured wrt an electron at T = 2 degrees Kelvin , absolute zero velocity could be approximated without any significant loss of experimental integrity.
That is my point in fact. If no one can tell, why assume the impossible to achieve something, just because the mathematics allows the operation?

Wespe, would you ever make the physical assumption that a train station was moving and the train right there in fornt of the station was stationary, assuming you noticed a relative motion between the two?

I say you would not. What then is the value or even validity of making such an assumption? You might do it to solve some aspect of a problem but you would never assume the physical reality of the assumption.

To understand it clearly, assume the rods are very very long. You can't see both ends at the same time, how will you compare them as they pass next to each other? You must place synchronized clocks on each end and make two simultaneous measurements. That's is where relative simultaneity kicks in.

You mean one couldn't simply photograph the front and tail ends of the rods as they pass through a measuring scheme and determine which is which? Supposed we had the rods start with equal lengths and kept them fairly close to each other as their velocity was manipulated and then we measured to see which was the shorter? I don't understand your simultaneity comment.

Well they can calculate what each other measures. But SR predicts their own measurements will be like that: each sees her own rod normal and the other's shorter.

right each can do this but they can't both be correct when the nitty meets the gritty at some common measuring spot, can they? This iis what I mean about mathematics of SR allowing and even encouraging this type of assumption. IS it physically possible, then if so is it physically reasonable?

wespe

Jun27-04, 04:04 AM

You mean one couldn't simply photograph the front and tail ends of the rods as they pass through a measuring scheme and determine which is which? Supposed we had the rods start with equal lengths and kept them fairly close to each other as their velocity was manipulated and then we measured to see which was the shorter? I don't understand your simultaneity comment.

This seems to be the key point, so I'll comment on this only.

Yes, you can photograph them. But, you must also take note of the times of the taken photographs. Suppose, just suppose, that your rod is 2 meters long and the passing rod is 1 meter long and there is no contraction. Naturally, the ends would not pass each other at the same time, and the photographs would be taken sequentially. By knowing the difference in these time values, you could calculate how long the other rod is. Now, make the other rod 2 meters again. Due to relative simultaneity, the ends cannot meet at the same time, and you would calculate a length smaller than 2 meters, just like the above example. And since relative simultaneity is mutual, so is length contraction. If you ask why can't they meet at the same time: because that would be a moment simultaneous in both frames, which is not ok with relative simultaneity. (Of course I know you don't accept relative simultaneity, but when all the effects are combined, SR seems consistent within itself.) [the above explanation may be a simplification and may be not 100% correct, that's just how I think it is explained]

grounded

Jun27-04, 06:10 AM

Originally Posted by grounded
Before we go on, do you agree that the Lorentz contraction was created to explain why we DID NOT measure a change in the speed of light when it traveled against the aether during the Michelson-Morley experiment?

Yes. The contraction would cancel the effect of aether resistance.

Well, since aether was dismissed, it isn't currently used to expain anything about aether. As I wrote before, if you want to assume aether exists, you can treat it like any other frame of reference, and the length contraction explanation would appy.

You missed my point, I do not believe in the aether.

The MMX was testing the relative speed between a ray of light and the aether.

This is the experiment they conducted with the interferometer:If a ray of light is moving through space in the direction of the ether flow at 300,000 km/sec (186,000 mi/sec), and an observer is moving in the same direction as the ether flow at 29 km/sec (18 mi/sec), then the light should move past the observer at the rate of 299,971 km/sec (185,982 mi/sec); if the observer is moving in the opposite direction of the ether flow, the light should move past the observer at 300,029 km/sec (186,018 mi/sec). It was this difference that the Michelson-Morley experiment failed to detect.

Since there is no aether, there was no change in speed.

My point is, if there is no aether, the MMX was accurate. Agree?

Why are we still trying to make up reason why it isn't accurate?

Suppose you simply explain MMX result with length contraction.

Can you tell me why we have to explain the results?

We didn't measure a change in speed because there is no aether that resists the motion of light.

Why did Lorentz and Einstein have to explain why we didn't measure the resistance?

geistkiesel

Jun27-04, 07:18 AM

This seems to be the key point, so I'll comment on this only.

Yes, you can photograph them. But, you must also take note of the times of the taken photographs. Suppose, just suppose, that your rod is 2 meters long and the passing rod is 1 meter long and there is no contraction. Naturally, the ends would not pass each other at the same time, and the photographs would be taken sequentially. By knowing the difference in these time values, you could calculate how long the other rod is. Now, make the other rod 2 meters again. Due to relative simultaneity, the ends cannot meet at the same time, and you would calculate a length smaller than 2 meters, just like the above example. And since relative simultaneity is mutual, so is length contraction. If you ask why can't they meet at the same time: because that would be a moment simultaneous in both frames, which is not ok with relative simultaneity. (Of course I know you don't accept relative simultaneity, but when all the effects are combined, SR seems consistent within itself.) [the above explanation may be a simplification and may be not 100% correct, that's just how I think it is explained]

What about one photograph of two rods that fit within the photgraph? If the rods are close enough and the shrinking large enoiugh then the observers could determine the relative speeds and motions of each other, could they not?

One definition I have here is: "Events simultaneous with reference to the stationary frame are not simultaneous with respect to the moving frame, and vice versa (relativity of simultaneity)."

Not to beat a dead horse but this definition was taken from Einstein's train experiment where the fact that the moving platform was moving and that an observer once located at the midpoint of the A and B photon sources in the stationary frame has moved from that midpoint and thereby she surrenenders any chance of measuring the photons simultaneous arrival at the midpoint in the stationary frame, or simply she is no allowed to to determine the photons were emitted sijultaneously in any manner excepts measuring the simultaneous arrival of the photons at M in the stationary frame. There is no reference by Einstein or any other source I have been able to find that suggest the the measured speed of light is an element determining whether events are simultaneous.

At this point then it matters not that we are using the photons as the medium determining simultaneity. It is from the mere measurement of the photons in sequence at B then A that contains the definition of simultaneity. What is somewhat disturbing is the statement where observers in the moving frame "must therefore come to the conclusion that the lightning flash at B took place earlier than the lightning flash at A." All other means of determining simultaneity have been discarded.

If this was, and it is the current definition of simultaneity then the definition is flawed. The only question the moving observer needs to do in order to determine whether the events in the stationary frame were simnultaneous is to determine whether the photons were emitted simultanously, or not. The fact that the photons were observed sequentially in the moving frame does not limit to that process. The observers could make a number of a measurements and analyses that could verify whether the photons could be detected as being emitted simultaneously in the moving frame. In other words if the observers in the moving frame can determine the photons were emitted simultaneously in the mcving frame then simultaneiity of the events is satisfied.

I claim I have done this in a number of posts and links.

But let us proceed on and see what is the result of the finding the photons were not enmitted simultaneously. Here every reference body has its own particlular time, unless we are told the reference body to which the statement of time refers, there is no meaning in a statement of the time of an event.

The absolute nature of time is scrapped from the adoption of the "most natural definition of simultaneity". i.e. the sequential detection of the B and A photons.

The definition seems to be saying that knowing the photons were emuitted in the stationary frame does not rescue simultaneity as the observers have concluded the photons were not emitted simultaneously in the moving frame,by virtue of the sequential measurement iof the A and B photons.

Therefore, I conclude that any determination that the photons were emitted simultaneously will restore the simultaneous characteristic of any particlular process.

From this loss of simultaneity moving observers will determine their own destiny of motion independent of stationary observers or observers in other inertial frames.

The mere fact that the moving observer at M, the midpoint of the photon sources, moved the instant the photons were emitted negated the survival of simultaneity, as it appears, the mere fact of detecting the photons sequentially set the chain of physical action that negagted absolute time, simultaneity and the propagation of light in vacuo become measurably constant in all inertial frames.

If only the moving observer could determine the photons were emitted simultaneously, from her observation limited by the intrinsic parameters of her moving frame, there would be no special relativity.

Special Relativity hangs by a thin and questionably fragile thread. I surmised I was close [I claim I've done it] to showing a way the moving observer could very easily determine whether the photons were emitted simultaneously or not from the panicked manner in which one of the posters to my thread began unleashing a barrage of ridicule, smirking, insults and purposfully confusing my posts and claiming conclusions and statemens in the post that were not made or inferred. He is a mentor so I suppose he is immune to any corrective process.

The French have a word for it: Sabotage.

wespe

Jun27-04, 02:11 PM

You missed my point,

sorry my bad

I do not believe in the aether.

The MMX was testing the relative speed between a ray of light and the aether.

This is the experiment they conducted with the interferometer:

Since there is no aether, there was no change in speed.

My point is, if there is no aether, the MMX was accurate. Agree?

Why are we still trying to make up reason why it isn't accurate?

Well, if speed of light doesn't change in one frame, and also in another frame which has a relative speed wrt that frame, there are consequences.. namely relative simultaneity, time dilation and length contraction (this time between those frames).

Grounded, I feel like I'm just repeating what I had read somewhere. It would really make things faster if you did some reading on your own and discuss only what bothers you.

Here are some good lectures:
http://galileoandeinstein.physics.virginia.edu/lectures/lecturelist.html

wespe

Jun27-04, 02:44 PM

What about one photograph of two rods that fit within the photgraph? If the rods are close enough and the shrinking large enoiugh then the observers could determine the relative speeds and motions of each other, could they not?
Well, the photograph machine has a shutter thing that opens and closes quickly and lets light in. We assume it opens simultaneously over all the points of the photo sensitive film, and so we assume we can take a photo of a single instance. But according to the passing frame, it will not be simultaneous, so possibly the taken photo will be blurry. I'm not really sure. But instead of making the rods small, make the photograph machine large, then you can't get away without synchronization procedure. Remember a very long shutter will not really be rigid.
[edit: oops I didn't answer your question. Yes, if you measure the shrinked length, and you were given the rest length, you can calculate the gamma and therefore relative speed and everything. But you can also measure relative speed directly. no time, have to go now..]

One definition I have here is: "Events simultaneous with reference to the stationary frame are not simultaneous with respect to the moving frame, and vice versa (relativity of simultaneity)."

Not to beat a dead horse but ............

Geistkiesel, I'm not willing to go into that discussion again with you. Simply, Einstein defines a method to test simultaneity and shows that according to that method the results are so. You can't discuss that. If you don't like it, find a method to test your version of simultaneity and test it in both frames and show that the results are same. Maybe someone else will reply to your post. I'm done in this thread.

ram1024

Jun27-04, 07:27 PM

I do know a thing or two about information transfer, and I "KNOW" that what you are saying is just wishful thinking.

apparantly you don't know enough. go read how data today is sent in binary bits <mostly>

apply some rational thinking on how the simple states of ON and OFF are combined together to create meaning. use some of that wondrous brain power you tote about on your neck every day to understand there's no need to get any other "information" from a single "pipe" EXCEPT 1 or 0. which is WHAT they DID get.

48 bits of data through 48 channels <pipes> reaching the other end 300 times faster than the speed of light. let's assume on the other end you see THIS:

01101000
01101001
00000000
01101101
01101111
01101101

each line being the ends of 8 pipes
each pipe transmitting merely ON or OFF
each line translating to 1 letter

the message reads "hi mom"

it's simple, why are you confounded by it?

Hurkyl

Jun27-04, 07:36 PM

On / off? I didn't know anybody still used that!

swansont

Jun28-04, 05:53 AM

ram1024

Jun28-04, 11:52 AM

doesn't matter what "leaves"

Michael F. Dmitriyev

Jun29-04, 12:07 AM

The Velocity of VISIBLE LIGHT is absolute. The relativity can’t be applied to it.
At increasing of frequency the properties of light would be changed :
Visible light--> X-ray-->Gamma-->Particles

Ingvar Astrand

Jun29-04, 06:45 AM

russ_watters

Jun29-04, 09:15 AM

I was away for the weekend and wow....you guys always talk about "the data" as if it proves the theory. yet surprisingly no one brings forth the actual data. I suggested we get off these useless thought experiments (useless because you refuse to accept what they say) and look at what the data says some time ago. In any case, you're wrong (yet again) - there are quite a number of threads where the actual data is cited, including THIS (http://www.physicsforums.com/showthread.php?t=27526)
bizarrely titled thread. It contains several weeks worth of reading material for you. Don't soil that thread with attacks though: if you want to address any of that evidence, start a new thread in TD and cite the articles posted in that thread.

Anyway, I'm not sure you realize it, but you've turned an important corner by shifting off of thought experiments and turning your attention to the evidence. Unfortunately, you have turned in the wrong direction: make sure you include the data about scientists getting light to travel 100 times faster than normal calculated speeds using cold caesium chamber and group resonance beams of light. Furthermore, every analyst of this experiment has concluded that information was not sent faster than light. Aren't you even the least bit curious as to why? i've already read about "why"

they're coming to the wrong conclusion...[emphasis added] Ok, you need to stop right there, take a step back, and consider the implications of what you are saying here.

You are saying that a peer-reviewed, published paper written by a trio of PhD's from Princeton is wrong. I'm not generally one to go resume' waving, but what qualifications do you have that can possibly come close to matching theirs and being able to say that?

It doesn't stop there though. Since this paper is peer-reviewed and published, thousands of other scientists have read it. If there was a glaring error in the paper, it would have been found. You are saying that you found an error that thousands of other scientists have missed. But you don't stop there: in any case i'm sure they adequately realize the potential of their results, but don't want to "give" any of the technology away if they can help it.

[separate post] they know it too since they work in the business. i'm pretty sure "it can't be done" is either fog to keep competition away from what they're going to pioneer as new technology OR their data is faulty and they have no idea what they're talking about (their experiment is a sham).

take whichever of those two conclusions makes you feel the safest... :D Now you are saying that the scientists know about your objection and agree with it, but are decieving us about what the implications of their experiment are (or, like you said before, don't realize their own experiment is flawed). And of course, you alone discovered the deception where thousands of other, more qualified scientists have not.

By the way, picking the second conclusion would mean that you are wrong (if your interpretation is based on their faulty data, then your interpretation is wrong). So you must think these scientists are lying. Either way though, there are two possibilities of why the rest of the scientific community hasn't picked up on it: either the rest of the scientific community missed the mistake too (but you caught it), or the rest of the scientific community is in on the conspiracy.

Stop and think about that. Do you really believe you are smarter than the next 1,000 physicists put together? Do you really believe there is a vast conspiracy to keep SR in place? Would that make us at PF a part of that conspiracy (and if we are, it isn't worth talking about it here, is it?)?

Ram, you've taken a left turn and left logic and reason behind you. It seemed for a while that you were making an honest effort to understand what we were saying, but not anymore. Its not too late to turn around, but you've gone far enough down that road you'll need a large, self-deprecating mea culpa to get you back a shred of respect/credibility here. If you're not just another conspiracy theorist troll, you need to turn back from that path right now.

If you're going to claim conspiracy theory regarding every experiment proving SR, further discussin is utterly useless. Why even bother?

geistkiesel

Jul2-04, 12:49 PM

You missed my point, I do not believe in the aether.

The MMX was testing the relative speed between a ray of light and the aether.

This is the experiment they conducted with the interferometer:

Since there is no aether, there was no change in speed.

My point is, if there is no aether, the MMX was accurate. Agree?

Why are we still trying to make up reason why it isn't accurate?

Can you tell me why we have to explain the results?

We didn't measure a change in speed because there is no aether that resists the motion of light.

Why did Lorentz and Einstein have to explain why we didn't measure the resistance?

Grounded, You had better take a good look at MM and Dayton iller. Both found a relative aether velocity difference of approximately 8.5 km/se. T^his was dubbed as "zero' by hiostory. Miller's rehash of MM experiments over twenty years (MM experiments were over a few days) confirmed the 8.5 km/sec number. Dayton Miller emphacises in his 1933 paper, Reviews of Modern Physics, Vol 5 203 242 a must reading, that MM stated that the aether drag was less than 1/4 of the earth orbital velocity of 30 km/sec.

Most scientists today use the 30km/sec orbital velocity which is the correct velocit wrt the sun, but the solar system is moving toward Hercules at about 22 km/sec, but Hercules is moving toward the southern apex at ~ 204 km/sec Toward Dorado, the Sword Fish 20 degress south of Canopus in the Magellenic Cloud.
The plot thickens.The average was derved using sidereal time at chosen times of the year diurnal effects!, April and Feb ? (I'm not sure) But the effect was real..

MM was not null!!!!

start here.
http://www.orgonelab.org/miller.htm

wespe

Jul2-04, 02:23 PM

MM was not null!!!!
start here.
http://www.orgonelab.org/miller.htm

If you have bothered to read it, there was an estimate of 208 km/sec, found 8.5 km/sec, and explanation of lowered speed to 10 km/sec due to dragged aether. So whatever value you find, you can say the speed is lowered to that value. What I understand from "null" is that the result was not scientifically meaningful. But let's suppose you can measure a speed (however small) in a certain direction. Just rotate the equipment 90 degrees and the fringes would disappear. Rotate again and fringes would appear. This certain direction would be demonstratable in 5 minutes. Why didn't miller do that? It is most probably eperimental error. From the photos, the experiment looks crude. And do you think the experiment was not repeated with modern equipment? If the results were real, anyone could get a Nobel prize, but they didn't want to?

geistkiesel

Jul2-04, 08:26 PM

If you have bothered to read it, there was an estimate of 208 km/sec, found 8.5 km/sec, and explanation of lowered speed to 10 km/sec due to dragged aether. So whatever value you find, you can say the speed is lowered to that value. What I understand from "null" is that the result was not scientifically meaningful. But let's suppose you can measure a speed (however small) in a certain direction. Just rotate the equipment 90 degrees and the fringes would disappear. Rotate again and fringes would appear. This certain direction would be demonstratable in 5 minutes. Why didn't miller do that? It is most probably eperimental error. From the photos, the experiment looks crude. And do you think the experiment was not repeated with modern equipment? If the results were real, anyone could get a Nobel prize, but they didn't want to?
It depends on what you consider crude. The experiment hasn't been repeated with quite the care since Miller, to my knowledge.
One reason Miller didn't do it is the rate of speed the device could turn. It weighed considerable floating in a bath of mercury, it wasn't a simple matter to stop and turn on a dimes., momentum is what they call it.

The vast majority of writers that i have read eferring to MM talki terms of null meaning zero, no affect stc, clearly this was not the case.
You might find the following of interest.

The effect [of ether-drift] has persisted throughout. After considering all the possible sources of error, there always remained a positive effect." — Dayton Miller (1928, p.399)

"My opinion about Miller's experiments is the following. ... Should the positive result be confirmed, then the special theory of relativity and with it the general theory of relativity, in its current form, would be invalid. Experimentum summus judex. Only the equivalence of inertia and gravitation would remain, however, they would have to lead to a significantly different theory."
— Albert Einstein, in a letter to Edwin E. Slosson, July 1925

"I believe that I have really found the relationship between gravitation and electricity, assuming that the Miller experiments are based on a fundamental error. Otherwise, the whole relativity theory collapses like a house of cards."
— Albert Einstein, in a letter to Robert Millikan, June 1921 (in Clark 1971, p.328)

I do not understand you. I read Miller to say that th average he found for the erth was around 8.5 km/sec as an ether drag. Michelson Morley found like numbers. but M stated that their value was less than 1/4 he rbital velocity of 30km/sec . therefore the 8.5 value is significnt no matter how you look at it. Miller also found the largest results diurnally using sideral time (April and Feb if I remember) The 208 km/s was the velocity of Hercules toward the southern apex, a direction clearly not considered by astronomers, even to day I presume. While we are moving approximately 20 km/s toward hecules hecules is moving over 200 kms to the south.

wespe

Jul3-04, 12:30 AM

It depends on what you consider crude. The experiment hasn't been repeated with quite the care since Miller, to my knowledge.

You should try to extend your knowlegde then.
I searched for Repetitions of the MMX
http://www.weburbia.demon.co.uk/physics/experiments.html
I searched for the last one in the list (1979)
http://fangio.magnet.fsu.edu/~vlad/pr100/100yrs/html/chap/fs2_07053.htm
See, it "has been repeated with quite the care since Miller". (4000-fold improvement).
Also, still, anyone can repeat the experiment. Instant nobel prize. not.

One reason Miller didn't do it is the rate of speed the device could turn. It weighed considerable floating in a bath of mercury, it wasn't a simple matter to stop and turn on a dimes., momentum is what they call it.
Yes and this type of device is very sensitive to any movement so you can't just rotate it without effecting the results. Plus there are every kinds of effects from the environment including non uniform gravity. That's why the non-zero results have to be considered carefully.

The vast majority of writers that i have read eferring to MM talki terms of null meaning zero, no affect stc, clearly this was not the case.

Please see:
http://dictionary.reference.com/search?q=null
"Of no consequence" "Amounting to nothing"

Note that in the above 1979 paper, there is of course some measured random data, but the result is interpreted as null by the experimenters because it is not meaninful compared to estimated values and considering experimental errors.

You might find the following of interest.

Not very interesting because it doesn't say anything new. As I said before, sure, if the results are confirmed, the theory would be invalid. What we are discussing is the confirmation part.

I do not understand you. I read Miller to say that th average he found for the erth was around 8.5 km/sec as an ether drag. Michelson Morley found like numbers. but M stated that their value was less than 1/4 he rbital velocity of 30km/sec . therefore the 8.5 value is significnt no matter how you look at it. Miller also found the largest results diurnally using sideral time (April and Feb if I remember) The 208 km/s was the velocity of Hercules toward the southern apex, a direction clearly not considered by astronomers, even to day I presume. While we are moving approximately 20 km/s toward hecules hecules is moving over 200 kms to the south.
I don't understand you either. I don't think you comprehend what you read and you just quote parts taken from somewhere without any grasp. I already knew you have a problem understanding what relative speed is, but this is just too much....

Michael F. Dmitriyev

Jul3-04, 02:00 AM

To Michael F. Dmitriev and the Forum:

The visible light is the frequency spectrum that your eye's retina reacts on as resonance absorption. In that meaning is visible light constant. But you don’t see (or yet understand) that redshift that is wave-elongation that is caused of an entropy-effect that drives the radiation towards equilibrium in the supra-leading temperatures in the cosmic background radiation's heat death.

Redshift implies wave-elongation, which implies that the electrodynamic waves increase in velocity that is proportional to the increased velocity. Light's velocity is the stroboscope-frozen spectrum that the eye reacts on and we do not se or understand (yet) that all the electrodynamic waves that increase in velocity have higher velocity than the light's velocity. Electrodynamic waves accelerates (1.986 x 10^-26 km/s^2) and it is not the galaxies or the universe that expands.

Planck did not find or understand that the difference between the wave-units that is 6.63 x 10^-34 is the fractional entropy-elongation of the waves that is proportional to the wavelengths. This is also the explanation to the redshift and the right redshift-constant that will replace Hubble’s misinterpreted redshift-constant. It is not the universe that is expanding -- but it is the electrodynamic waves that accelerate away.

My theory and its beautiful equations also explain Pound-Rebka's misinterpreted Mossbauer-experiment that is not a gravitation-effect. It also explains by insight and right values -- compared to the measured data -- the Pioneers' anomalous acceleration. Both those "experiment" have the same explanation and computing method of algorithmic equations.

An observer that moves relative to the radiation from a source have his eyes' optical (light) frequency spectrum invariant but the wavelengths appears as shorter in this relation [The eye's invariable frequency = (c+observer’s velocity)/wavelength]. The wavelengths change with the observer's light-frequency and proportional to his velocity. If he travels at c+10% of c, the wavelengths of his lightspectrum increase 10%. And the observer in rest sees the light's wavelength’s spectrum as it is, proportional to his velocity that is 0 –he sees the laboratory-relation between frequencies and wavelengths.

In August you can read on my homepage www.theuniphysics my great paper from the NPA&AAAS-conference in Denver in April 2004.

Ingvar Astrand, Sweden
Ingvar Astrand,
As far as I have understood, your theory connects a change of a wave length (frequency) with acceleration of this wave. Then the speed of radiowave in a long-wave range should multiply exceed the speed of visible light. Experiments with these radiowaves does not give the basis for such conclusions.
Do you have another results?

Michael

geistkiesel

Jul4-04, 12:45 PM

To Michael F. Dmitriev and the Forum:

The visible light is the frequency spectrum that your eye's retina reacts on as resonance absorption. In that meaning is visible light constant. But you don’t see (or yet understand) that redshift that is wave-elongation that is caused of an entropy-effect that drives the radiation towards equilibrium in the supra-leading temperatures in the cosmic background radiation's heat death.

Redshift implies wave-elongation, which implies that the electrodynamic waves increase in velocity that is proportional to the increased velocity. Light's velocity is the stroboscope-frozen spectrum that the eye reacts on and we do not se or understand (yet) that all the electrodynamic waves that increase in velocity have higher velocity than the light's velocity. Electrodynamic waves accelerates (1.986 x 10^-26 km/s^2) and it is not the galaxies or the universe that expands.

Planck did not find or understand that the difference between the wave-units that is 6.63 x 10^-34 is the fractional entropy-elongation of the waves that is proportional to the wavelengths. This is also the explanation to the redshift and the right redshift-constant that will replace Hubble’s misinterpreted redshift-constant. It is not the universe that is expanding -- but it is the electrodynamic waves that accelerate away.

My theory and its beautiful equations also explain Pound-Rebka's misinterpreted Mossbauer-experiment that is not a gravitation-effect. It also explains by insight and right values -- compared to the measured data -- the Pioneers' anomalous acceleration. Both those "experiment" have the same explanation and computing method of algorithmic equations.

An observer that moves relative to the radiation from a source have his eyes' optical (light) frequency spectrum invariant but the wavelengths appears as shorter in this relation [The eye's invariable frequency = (c+observer’s velocity)/wavelength]. The wavelengths change with the observer's light-frequency and proportional to his velocity. If he travels at c+10% of c, the wavelengths of his lightspectrum increase 10%. And the observer in rest sees the light's wavelength’s spectrum as it is, proportional to his velocity that is 0 –he sees the laboratory-relation between frequencies and wavelengths.

Ingvar I made some calculations assuming an arbitrary wavelength of 10^-8meters, for the condition of a stationary observer. A complete wavelength will pass the eye in (10^-8)/(3x 10^8m/s) = .3333 x 10^-16 seconds for a frequency of 1/.3333 x10^-16 = 3.0000x 10^16/sec.

Now when we add the obserevers speed of .1c we get the new relative velocity of 3.3 x 10^8m/s. For our unperturbed wavelength we calculate the new frequency by dividing the relative speed by the known wavelength, or (3.3x 10^8m/s)/(10^-8m) = 3.3 x 10^16/s.

Of course the wavelength is (3.3 x 10^8m/s)/(3.3 x 10^10-8m) = 10^-8m.

If the relative velocity is not considered we get 3 x 10^8m/s)/(3.3 x 10 ^16/s) = .9090 x 10^8m.

Redshift implies wave-elongation, which implies that the electrodynamic waves increase in velocity that is proportional to the increased velocity.

First you must ovecome the constant velocity of light in vacuo ~ 3 x 10^8m/s and then ovecome the implication that frequency increases cause the red shift.

It is the conclusions of some that the mere measuring of a wavelength of light does not squeeze the wavelengths shorter when passing the eye and is not affected by entropy considerations as you suggest. However, the frequency of the passing wavelengths is increased as I have calculated when the obsever's relative velocity is considered.

Does it not seem more rational that the frequency will increase rather than the wavelength decrease? Red shift is an incease in the frequency in doppler measurements, not a shortening of wavelength. :smile:

ram1024

Jul4-04, 01:12 PM

geistkiesel

Jul4-04, 03:21 PM

well to the people preserving SR, you moving towards a light or away from it affects the frequency which in turn automatically affects the wavelength.

the thing is, greater frequency, but shorter wavelength doesn't mean anything to someone with time dialation and length contraction. in their units they can't detect redshift.

You are correct. The SR people do not add the relative velocity of the moving observer, therefore they will always measure a shrunken wavelength, which the ascribe to time dilation and mass shrinking etc and will always measure c = 300,000km/sec with the dilated time and shrunken mass.
I am niot considering shortened mass, only increased frequency. You are correct they use FL = C blindly. Even Maxwll only said that "a shortened wavelenth means generally a faster fr3equency" He diod not say, expressly that FL = c blindly. I have griossly parphrased maxwell in this.

But to others moving into the on coming wave front does not squeeze the wave length shorter. However, the frequency does increase. If a wave is coming you at velocity 10distance/time and you are stationary and say you detect the wave length at 1distance. Therefore the wavelength will pass you by at 1/10 (length divided by speed) = .1 (in time units) The frequency is just the reciprocal of this, or 1/.1 = 10/time.

Now move against the wave at .1 unit of speed. The combined relative speed is 1.1distance/time. Calculating the frequency using the known wave length 1, we get 1/1.1 = .9090 sec for the time the wave takes to pass you. The frquency is the reciprocal, just 1/,9090 = 1.100/time, an increase in frequency. Now let us calculate the wave length using the measured frequency but not including the velocity of the observer.

1/1.100 (wavelength velocity divided by the measured frequency) ~.9090. We have a shortened wave length by, 1 - .9090 = .091, by not considering the observer's velocity. One problem though. This calculation does not agree with SR calculation of a shortened wave length, which may mean the added velocity scenario is correct, or needs further adjustment. So there is a bit more to the story.

Ingvar Astrand

Jul6-04, 04:44 AM

Ingvar Astrand's answer to geistkiesel:

Does it not seem more rational that the frequency will increase rather than the wavelength decrease? Red shift is an incease in the frequency in doppler measurements, not a shortening of wavelength. :smile:

No redshift implies increasing wavelengths and decreasing frequencies.
The frequencies of the wave-units that the moving observer meet increase (he meets the wave-units faster) and he sees longer waves that appears shorter to him. So the light-spectrum he sees have - depending on his eyes' invariant frequency-reaction - longer wave-lengths in the reality (relative to the space or the observer in rest).

The complicated Doppler-formulas do hardly explain what really happens.

An observer that moves forwards relative to the radiation from a source have his eyes' optical (light) frequency spectrum invariant but the wavelengths appears as shorter to him [the eye's invariable frequency = (c+observer’s velocity)/wavelength]. The wavelengths of the light spectrum that appear as (is) normal for the moving observer's eyes are wavelengths that relative to the space in rest are longer.

The apparent wavelengths are the variable parameter that is changed proportionally with the observer's velocity depending on his eyes' inherent invariable light-frequency-reaction. If he travels at c+10% of c, the wave-units he sees (appears to him) as normal are the true wavelengths that are 10% longer. And the observer in rest sees the same wavelength’s spectrum as it is, proportional to his velocity that is 0 – that is: the laboratory-relation between frequencies and wavelengths

Let me refer to your example: First: frequency = velocity / wavelength
Let us calculate a specific yellow color of 6000 A (Angstrom) or 6 x 10^-7 m.

An observer in rest sees this yellow color's (laboratory-)frequency at (3 x 10^8m/s) / (6 x 10^-7 m/n) = 5 x 10^14 n/s (Hz)

Independent of his velocity this yellow color to him always has the frequency: 5 x 10^14 n/s (Hz).

If an observer moves at c+10% of c, his yellow color's wavelength is: (3.3 x 10^8m/s) / (5 x 10^14 n/s) = 6.6 x 10^-7 m (6600 A).

My derivation of the real theory of relativity is: symmetric, understandable, calculateable, and no crazy dilation of space or time. Now you need neither Lorentz' unintelligible equation nor Doppler's hardly explainable formulation.

I have presented my wholw "unified theory of physics" with this transition calculation (translation formulation) in proceedings at conferences in Kazan State University in Russia 2003, and with NPA and AAAS in Denver 2004.
In August you can read my whole theory at: http://www.theuniphysics.info

But till then, take a look at my Denver-abstracts and see the great range of the unified theory of physics.

geistkiesel

Jul9-04, 02:20 AM

I understand your post. It seems to me arbitrary, which doesn't make it erroneous, that an intrinsic characteristic of the light, i.e. the wavelength would change, lengthen, and the frequency would be the determining factor? Do you see my "realist" conundrum?

How does the wavelength get modified during measurement anyway?

ram1024

Jul9-04, 05:58 AM

If an observer moves at c+10% of c, his yellow color's wavelength is: (3.3 x 10^8m/s) / (5 x 10^14 n/s) = 6.6 x 10^-7 m (6600 A)

nah he's saying the color that the observer WOULD perceive as being "yellow" would be modified versus standard earth measurements because to get that frequency he'd have to subtract his own velocity.

but the eyeball doesn't subtract velocity on its own, so on paper yellow is 6.6x10^7 m to him at that speed

russ_watters

Jul9-04, 08:44 AM

the thing is, greater frequency, but shorter wavelength doesn't mean anything to someone with time dialation and length contraction. in their units they can't detect redshift. Have you actually done the math or do you just assume that it works out that way?

ram1024

Jul9-04, 07:07 PM

no i haven't, i'm not an SR person. from what i GATHER, you guys can't detect redshift as we define it, only doppler redshift from motion of the stellar bodies.

why don't YOU tell ME :D

geistkiesel

Jul10-04, 02:23 AM

You should try to extend your knowlegde then.
I searched for Repetitions of the MMX
http://www.weburbia.demon.co.uk/physics/experiments.html
I searched for the last one in the list (1979)
http://fangio.magnet.fsu.edu/~vlad/pr100/100yrs/html/chap/fs2_07053.htm
See, it "has been repeated with quite the care since Miller". (4000-fold improvement).
Also, still, anyone can repeat the experiment. Instant nobel prize. not.
Your 4000 fold improvement number is questionable. The authors there mentioned MM and Joos, and ignored Miller who did approx. 200,000 MM type experiopments with the known results. Miller questioned Joos' experimental technique. The authors also assume a relativity scenario carrying through the experiment ( as far as I can tell). Personally I think the 79 paper is scientific junk.

Yes and this type of device is very sensitive to any movement so you can't just rotate it without effecting the results. Plus there are every kinds of effects from the environment including non uniform gravity. That's why the non-zero results have to be considered carefully.

Please see:
http://dictionary.reference.com/search?q=null
"Of no consequence" "Amounting to nothing"

Note that in the above 1979 paper, there is of course some measured random data, but the result is interpreted as null by the experimenters because it is not meaninful compared to estimated values and considering experimental errors.
the 79 paper authors mentioned some data not considered. They also used diagnositc data in their results. You should read it a tad closer.
I give them a J for junk grade.

Th3e definition is always a matter of choice. What is null to wespe may be of monumnetal importance to someone else. Un;less the "null" or of no importance is quantified it is usless to me.

Not very interesting because it doesn't say anything new. As I said before, sure, if the results are confirmed, the theory would be invalid. What we are discussing is the confirmation part.

I don't understand you either. I don't think you comprehend what you read and you just quote parts taken from somewhere without any grasp. I already knew you have a problem understanding what relative speed is, but this is just too much....

I understand enough for me. Whether it is enough for you is not a concern of mine. I know what relative speed is. The only problem you have with that is it contradicts your SR store bought vesion of physics.