Measuring The Relative Velocity Of Light

[quantumdude]

Neither one of you understands how light propagates[/color].

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[/color])-∂²E+(1/c)(∂/∂t)∂xB[/color]=0

The part in blue[/color] vanishes by virtue of equation (3), and the part in red[/color] 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:

A_i(x,t)=A_i0sin(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)A_i=0

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

Notice that the above equation is not a wave equation[/color]. 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.[/color]

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]

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]

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]

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

Unfortunately, your thread has kinda been hijacked. Let's 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]

My above post is a lot to chew on, but let me 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 that's 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.

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]

My above post is a lot to chew on, but let me 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 that's 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.

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]

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.

 

[quantumdude]

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.

 

[quantumdude]

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.

 

[quantumdude]

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]

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]

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

You must consider that Grounded has made a number of choices that is transcendental to prevailing understanding. He, we, aren't throwing a hapless momma from the train. No one is hurt, nor is progress impeded when someone makes a leap and jumps to the head of the line.

 

[geistkiesel]

I submit to the replacement.

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[/color].



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[/color].

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]

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]

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.

 

[quantumdude]

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.

 

[quantumdude]

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.

 

[quantumdude]

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]

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]

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

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]

Please Read All Before Responding

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 let's 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 let's 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]

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 let's 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.

 

[quantumdude]

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 non[/color]relativistic 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.[/color]

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 let's 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[/color] 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[/color] 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.[/color]

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[/color]. 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![/color].

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[/color] 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[/color], 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]

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.

 

[quantumdude]

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[/color], 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]

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?

 

[quantumdude]

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]

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]

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]

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