Can motion be detected without external reference in a moving container?

[Bigman]

god, there's a lot of background i don't have (and i still can't get over the whole "they both observe each other as aging slower" thing!), but this is starting to make more sense to me, especially after reading some of the article in that link(which is really helpful, thanks!). i just finished the general relativety part, where he says that the guy on Earth would appear to age quickly from the frame of reference of the girl in the ship while she's turning around, due to "uniform gravitational time dilation"... what is "uniform gravitational time dilation"? does it apply to all objects which are observed to be accelerating, or is there more to it?

 

[wisp]

In "Galilean Electrodynamics", a crank anti-relativity journal. Please do no link to such sites.

I can't find any experimental evidence that supports relativity's claim that the laser light goes perpendicular in a moving frame. Do you have any links? Or is it not necessary to test this under relativity rules?

I've come across a few amateur experimenters claiming laser light lags when the laser beam rod is rotated.

If someone carries out an experiment that proves light lags, are they automatically labeled crank anti-relativity?

If I carried out an experiment with a laser on a rotating rod, there are two outcomes.
1. The spot doesn't move when the rod is move to different directions.
2. The spot moves, lags at certain directions.

If the outcome is (1). I take it the experiment is valid, because it supports relativity.
If the outcome is (2). Relativity is false. But I will be labeled a crank and relativity remains intact.

I would argue that whatever the result is, it is scientific evidence. To automatically class results that challenge relativity as crank is bad science.

 

[1effect]

I can't find any experimental evidence that supports relativity's claim that the laser light goes perpendicular in a moving frame. Do you have any links? Or is it not necessary to test this under relativity rules?

I've come across a few amateur experimenters claiming laser light lags when the laser beam rod is rotated.

If someone carries out an experiment that proves light lags, are they automatically labeled crank anti-relativity?

If I carried out an experiment with a laser on a rotating rod, there are two outcomes.
1. The spot doesn't move when the rod is move to different directions.
2. The spot moves, lags at certain directions.

If the outcome is (1). I take it the experiment is valid, because it supports relativity.
If the outcome is (2). Relativity is false. But I will be labeled a crank and relativity remains intact.

I would argue that whatever the result is, it is scientific evidence. To automatically class results that challenge relativity as crank is bad science.

It cannot "lag". There is something magical called "aberration of light", the equations were first described by Einstein here, that tells you that the laser beam magically angles itself forward , in the sense of motion, rather than backwards.People who write about "lagging", don't know ...You can also read here

 

[yuiop]

...

I've come across a few amateur experimenters claiming laser light lags when the laser beam rod is rotated.
...

it is true that there will be a lag when a laser beam is rotated, but rotation is a form of acceleration and so a rotating reference frame is not an inertial reference frame and special relativity is not violated. It is easy to detect the rotation of a closed system without reference to anything external.

 

[wisp]

It cannot "lag". There is something magical called "aberration of light", the equations were first described by Einstein here, that tells you that the laser beam magically angles itself forward , in the sense of motion, rather than backwards.People who write about "lagging", don't know ...You can also read here

Re: Set up #1.
Your right, stella aberration is known and tested and implies that the photons leaving the lasers travel away from in a perfectly straight lines with no lagging - regardless of any absolute frame.
It is not possible to use this method to detect absolute motion.

Re: Set up #2.
Detection of absolute motion is not possible using spectrum analysers. In the moving frame box, the frequency will read the same at all sides.

However, things are not as simple as they appear. Consider a laser A at rest in an absolute frame emitting a photon A. At the same point and time in space a moving laser B overlaps A and emits photon B. Both photons travel in directions that their respective lasers point.
With regards to the absolute frame, photon A travels at speed c. Photon B travels at speed c along a line that forms the hypotenuse of a right angled triangle, with points (Laser A); (Photon B) and (laser B). Now in one second of absolute time, laser B has traveled V along the x-axis, and photon B has traveled = Square root of (c^2 – V^2) along the y-axis. Therefore, photon B reduces its wavelength by virtue of a slower speed.

A possible set up #3 to detect absolute motion is to place a diffraction grating in the path of the moving laser. It could diffract the light differently because of changing wavelength, which depending on its direction and speed relative to the absolute frame.

 

[Ian Davis]

The article cited is not much use in explaining the twin paradox because it introduces acceleration to explain the paradox which a red herring. The paradox exists without introducing acceleration, so introducing acceleration to explain it is a real cheat.

Consider two observers who each have clocks consisting of a light pulse bouncing between 2 vertical mirrors set 4 ft apart. Let one observer pass the other at a speed
of 3/4c. Then they and their clock travel 3 ft every time the light travels 4ft. The observer moving with their clock sees light move 4 ft, the stationary observer 5ft (3-4-5 right angle triangle)/ For the two observers to agree on its velocity as c, since velocity = distance/time we have 4/t1 = 5/t2 or t1/t2 = 4/5 where t1 and t2 are the observed passage of time for the light to travel from one mirror to the other. So the moving observers clock ticks 4 ticks for every 5 the stationary observers light clock ticks.

The stationary observer can compute this, and thus conclude that the moving observer
is aging more slowly, because their light clock is running slower. But the entire arrangement is entirely symmetric, and the moving observer can conclude that because they are stationary, the actual equation is t2/t1 = 4/5. The paradox is to explain how 4/5 = 5/4. Worse by symmetry have each travel 3/8c away from the other, at the same speed but in opposite directions, instead of arbitrarily claim one stationary and the other moving. Then they will conclude that while each has a clock somewhat slowed by their mutual but opposite velocities, their clocks are each slowed by the same amount relative to a stationary clock and thus are in sync, contradicting the earlier observations.

So it appears that the two observers can choose how much time they wish to trade for how much distance, merely by changing the rules about what constitutes the means of measuring distance. The geometry of how they measure distance is easily grasped. It is simply a consequence of the universal metric (x^2+y^2+z^2-t^2) being the same in all inertial frames, but none of the individual variables necessarily agreeing between two observers.

The hard part is understanding what actually happens to an individuals watch, merely as consequence of declaring light travels 4ft or 5ft. It may be that merely announcing that I am traveling at 3/4c, slows my watch by 4/5, which being slowed myself I fail to observe any change in, but this makes something of a mockery of the notion of time being fixed, even for one in an inertial frame. And what exactly is meant by two observers each having clocks that run slower than the others.

 

[wisp]

Re: A possible set up #3 to detect absolute motion is to place a diffraction grating in the path of the moving laser. It could diffract the light differently because of changing wavelength, which depending on its direction and speed relative to the absolute frame.

Taking account of time dilation effects in the moving frame. The photon B speed would be measured as c, wrt laser B, with normal frequency and wavelength readings. But in the forward and reverse directions the wavelength would decrease and increase respectively.

A laser diffraction grating experiment could possibly detect absolute motion.

 

[1effect]

A laser diffraction grating experiment could possibly detect absolute motion.

You will need to write down the equations of your proposed experiment .
When you do that, if you do it correctly, you will manage to prove to yourself that you are wrong. :-)

 

[mjordankeane]

Detecting Absolute Motion:
Tricky!
The "detection" part, not the absolute motion part.
Absolute motion: there are 2 absolute motions that everyone should agree to. The speed of light and abolute zero motion.
The speed of light has been measured and no matter what the velocity of the observer the speed of light measures the same. You can't get much more absolute than that.
Zero Velocity: if the Big Bang theory is correct and my interpretation of that theor is that everything in the universe collapses to a single point, and, if motion is movement from point A to Point B, the Absolute "zero" motion exists in the instant of the Big Bang. Therefore, absolute motion exists in at least 2 instances, zero motion and the speed of light. With these "absolute motion" boundries it seems a model could be created projecting absolute motion from a Big Bang origin to the present.

 

[ghwellsjr]

Unfortunately, even if you could say that one state of motion were at absolute zero motion, you could then move with respect to that one at a very large percentage of the speed of light and your new state of motion would be identical to the first one with regard to being just as far removed from the absolute speed of light. You cannot find a state of absolute zero motion as being half way between the speed of light in one direction and the speed of light in the opposite direction.

 

[mjordankeane]

Absolute zero motion, based on the previous premiss, would only exist in a singularity, in particular the Big Bang singularity, where not even light can escape, as the movie trailer goes. No light? No speed of light.
c?

 

[phinds]

Absolute zero motion, based on the previous premiss, would only exist in a singularity, in particular the Big Bang singularity, where not even light can escape, as the movie trailer goes. No light? No speed of light.
c?

You speak of the singularity as though you believe it to be a physical reality. That is not the believe of physicists. "Singularity" is a short-hand, the full statement of which is "the place where our theories break down and we don't know WHAT is happening".

EDIT: also, I don't know if you would be willing for your statement "no light, no speed of light" to be taken out of the meaningless context into which you put it, but if you are you might want to take into account that the "speed of light" that you are most likely referring to is the "universal speed limit" that does NOT depend on the presence of light (although light DOES obey it). In other words, I may be misinterpreting you, but I think you just said "no light, no universal speed limit" and that's not correct.

 

[whosapopstar?]

I wish that sometime in the 21st century there will be a children's museum that will prove hands on experiments of SR predictions - in the macro world - and will refrain from: 1.thought experiments and 2.from forwarding the children to a very long list of experiments that contain mainly particle physics experiments.

 

[yoron]

All motions are relative. But when it comes to being at rest there is one thing I find interesting. That all uniform motions can be defined as being at rest. It's not only a matter of taste, it's a true statement. And thought experiments are very important in physics, they help you visualize otherwise very intricate ideas, best described mathematically.

We have our ideas of what motion is, that comes from us always defining them relative our 'unmoving' Earth. The universe seems to use different definitions.

 

[mjordankeane]

I agree that the speed of light would still be the speed of light even in a singularity. I was being facetious.
To move on, if the premiss of the "Big Bang" is given as the event that started everything, and, that event is reduced to the exact instant of the Big Bang, then no event at all will have occurred to create an expanding universe for the purpose of this example of absolute zero velocity. At the first instant of this unique event, the Big Bang, the idea of absolute zero motion, and not "relative" motion, would be possible. And, in this instant relative motion would not be possible. Relative to what?
The reason why I believe the 2 absolute motions, absolute zero motion and the speed of light, are meaningful is that these 2 motions create 2 boundries for all "absolute" motions, and a graph of absolute motion can be created.
This premiss is dependent on treating the Big Bang event, as "a physical reality".

 

[ghwellsjr]

Let me try this again.

Let's say you could link the Big Bang event to a state of absolute zero motion at the present time and you identify that state as one of your boundaries and let's say you set the other boundary at the speed of light. Now if you travel at some high rate of speed you would be no closer to the speed of light than you were before you started. Your second boundary is like the pot of gold at the end of the rainbow, it keeps its same distance away from you no matter how fast you chase after it. So what do you think that does to your first boundary?

 

[phinds]

I agree that the speed of light would still be the speed of light even in a singularity. I was being facetious.
To move on, if the premiss of the "Big Bang" is given as the event that started everything, and, that event is reduced to the exact instant of the Big Bang, then no event at all will have occurred to create an expanding universe for the purpose of this example of absolute zero velocity. At the first instant of this unique event, the Big Bang, the idea of absolute zero motion, and not "relative" motion, would be possible. And, in this instant relative motion would not be possible. Relative to what?
The reason why I believe the 2 absolute motions, absolute zero motion and the speed of light, are meaningful is that these 2 motions create 2 boundries for all "absolute" motions, and a graph of absolute motion can be created.
This premiss is dependent on treating the Big Bang event, as "a physical reality".

I think the problem with this is that you are treating the singularity as though it were a physical event, but that's not what "singularity" means. What it means is "the place where our current theory totally breaks down and we have no idea what was happening".

So your belief that there was a point of zero motion is a personal belief, not one you can ascribe to physics as we know it.

You COULD, by the way, be right, but we don't know one way or the other, so stateing it as fact is what I'm objecting to.

 

[mjordankeane]

https://www.physicsforums.com/attachments/40083ghwellsjr said:
"Let's say you could link the Big Bang event to a state of absolute zero motion at the present time and you identify that state as one of your boundaries and let's say you set the other boundary at the speed of light.".
I'm confused by this part of your sentence that says "the Big Bang event to a state of absolute zero motion at the present time". The Big Bang happened, according to some, 14 billion years ago. In my entry I indicated the absolute zero motion was an occurrence at the exact instant of the Big Bang not the present. My argument is that at that point the universe was literally a single point and therefore relative motion was impossible as motion requires movement from one point to another. If there is only one point then movement from one point to another point is impossible.
Then motion occurs in conjunction with the Big Bang. The universe expands to more than a single point. Motion can occur and with this motion a limit occurs to that motion. Motion has a limit and that limit is the speed of light.
Directly proportional to motion is mass.
Absolute zero motion means absolute zero mass.
Motion at the speed of light means infinite mass.
The 2 limits of motion are absolute. You can not move any slower than absolute zero motion, or, any faster than the speed of light. Your mass can not be an less than zero mass and any greater than infinite mass.
You're right ghwellsjr, you can't reach the "absolute" speed of light and you can't get to absolute zero except except inside the Big Bang the instant of the Big Bang.
This is why I am describing these 2 absolute motions as absolute motion boundaries. Once these 2 absolute motion boundaries exist then speeds such as
1/10 c absolute motion and 9/10 c absolute motion exist.
1/4 c absolute motion and 3/4 c absolute motion exist.
And so on...
I've attached an image of a graph that takes the idea of these 2 boundaries and projects them into an understanding of how motion and mass proceed from zero to infinite mass.

 

[mjordankeane]

I think the problem with this is that you are treating the singularity as though it were a physical event, but that's not what "singularity" means. What it means is "the place where our current theory totally breaks down and we have no idea what was happening".

So your belief that there was a point of zero motion is a personal belief, not one you can ascribe to physics as we know it.

You COULD, by the way, be right, but we don't know one way or the other, so stateing it as fact is what I'm objecting to.

phinds, You mentioned 'What it means is "the place where our current theory totally breaks down and we have no idea what was happening".'

Then maybe it is a time for an idea.

You also said, "You COULD, by the way, be right, but we don't know one way or the other, so stateing it as fact is what I'm objecting to."

Thank you.

In order for any 'idea' to take shape and gain credibility certain agreements to the validity of an argument need to be brought forth and evaluated. If they are completely ridiculous, "moon made of green cheese" for example, they do not need to be seriously challenged and can be rejected by "Show me the cow!", however, I don't think the argument "When the universe, per the Big Bang, exists as a single point, and motion is described as movement from 1 point to another point, means that absolute zero motion exists in the Big Bang event." is on the order of the ridiculous.

Theories require certain agreements to be made. Not for us to chop off our frontal lobe and agree to them but not to reject out-of-hand either.

Eighty plus years ago an agreement was made on the structure of the atom being made up of 3 components": the proton; the neutron; and the electron, a model I happen to disagree with. This Quantum model was accepted at the time and a satellite model of the atom was invisioned. This model was replaced by other 3 component models as the satellite model was not functional, and these models in turn were replaced until the Heisenberg uncertainty left us with no clear distinction of what how the atom actually works because the act of looking at the atom disturbs our ability to discover what it is.

I think what finally occurs is functionality, in the end, defines validity. The old saying is "You can't argue with success." Some may believe the Quantum model exists because of its degree of success. However, I believe that its failures are keeping us from discovering what is occurring.
So, when I mention absolute motion versus relative motion I believe there is an argument that will lead to an understanding not found in Quantum physics. That everything isn't relative. That there are absolutes and thinking in this direction leads to understanding not found in Quantum Physics.
I'm going to try adding an attachment I tried adding earlier, to see if it attaches this time without difficulty...

 

[Petyab]

Consider that the observer is acting upon the box and the laser beam. Now it seems intuitive that the emitter would vibrate causing "virtual" (thought not) images due to the vibrational energy interference within the reference frame. I can get where the dogma is accepted that it won't, but consider that this oscillation would only cause an oscillation on the order of perhaps attometers let's say. An observer wouldn't typically recognize such a small shift? Who knows. The power of the brain is extraordinary and we react to the suns rays by transforming its irradiative energy into vitamins and chemicals which our body uses.

 

[phinds]

... So, when I mention absolute motion versus relative motion I believe there is an argument that will lead to an understanding not found in Quantum physics. That everything isn't relative. That there are absolutes and thinking in this direction leads to understanding not found in Quantum Physics.

well, good luck with that.

I'm going to try adding an attachment I tried adding earlier, to see if it attaches this time without difficulty...

attachment visible but not readable

 

[yoron]

Think of it as a scale, but with the scale being observer dependent. Your clock, and your ruler will define distances, time, as well as the relative motion of others. But, in reality, you're asking if the universe has a way to 'know' what a motion is, and there I think the answer is yes. 'Energy' is how the universe defines 'relative motion' and you gaining 'energy' will be a result of your acceleration, no matter if you define it relative Mars or Alpha Centauri.

So yes, the universe keeps 'count'. But that 'count' is nowhere in a uniform motion, you can't measure it. And to me it must have to do with 'room time geometry' somehow. But macroscopically there is no way I know of that you can define a 'energy' in a (uniform) motion. You can use some relative 'frame of reference', like the cosmic background radiation, or Earth, or measure the blue shift of light from distant stars, but in a black box scenario?
=

The question is trickier than it seems. We define energy from 'invariant mass' acting for example relative our Earth, and assuming that motion is relative our definitions of the 'energy' expressed in a collision, then they all should become arbitrarily made as we have no way of defining a absolute rest frame, only a relative. Or maybe its just me :) finding it trickier to define than it should be.

Then again, the universe has one definition of being at rest, uniform motion, and there is also the one where you're at rest relative something else. But I like uniform motion myself :)
=

Yep, that's a perfectly acceptable way of defining 'energy' locally, using 'uniform motion' as a state of rest I think. And then imagine yourself at rest relative it.

 

[dreamland37]

The only plausible arguments for absolute or those of Newton's buck and that of the tension in a rope tied to two rotating spheres. Even Einsteins equations were not able to solve it which is the reason he had to re-introduce the Ether. He said that if any solution to this problem could be found, it might answer the unified field theories.