The SR Question of the Century

Martin Miller

[russ_watters wrote:]
(Re the simple fact that even in SR anything that is at a
single point is certainly equidistant from any coincident
frame origins:)
This is true in Newtonian physics but not true in Relativity.
Which is correct? Do the experiment and find out.

[MM replies:]
Well, it's a darn good thing that you posted your specific
complaint, because my experiment was flawless, which means
that I would not have been able to pinpoint your area of
contention sans your help.

Since you have made the incredible counterclaim that it is
not true in SR, we would all love to see your proof of same,
but you can't produce proof because you are wrong; however,
just out of curiosity, what is your version of SR's version
of the two distances?

Re your request that I do the experiment and find out, this
shows that you haven't a firm grasp of SR because you are
blissfully unaware of that fact that SR's relativity of
simultaneity was based on the same experiment.

Specifically, it was based on Einstein's famous thought
experiment (which everyone who believes in SR accepts as
being as good as an actual experiment) involving the
observers on the embankment and the train.
[See Chap. IX of Einstein's _Relativity_]
http://www.bartleby.com/173/9.html

Even more specifically, we note that Einstein's two observers
in this experiment _both_ considered themselves to be _midway_
between the two events. Thus, they also considered themselves
to be equidistant from either event. Therefore, each observer
used the _same_ value X as the frame distance (in his own frame)
from either event when the events occurred.

So even Einstein agrees with me that when two observers meet in
passing as a light ray approaches that the tip of the ray is at
the same frame distance X from both observers.

Any more complaints?

Doc Al

Imagine that each observer's frame has a huge ruler extending along the x axis. You seem to be assuming that just because the two observers agree that the origins of their respective frames (x = x' = 0) are at the same place at the same time, that that somehow implies that they would agree that all points on their rulers (for example, ruler markings x = 10 meters) are simultaneosly coincident. Not true at all!

russ_watters

Einstein's experiment and yours are different. Since its your experiment and your claim, why don't you do the derivation instead of just asserting it over and over again?

Or are you suggesting that SR and Newtonian physics are mathematically equivalent?

DrChinese

From your cited reference of Einstein:

"Events which are simultaneous with reference to the embankment are not simultaneous with respect to the train, and vice versa (relativity of simultaneity). Every reference-body (co-ordinate system) has its own particular 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."

Seems pretty simple. Einstein says that simultaneity is in the eye of the beholder. Therefore, observers in different reference frames may see simultaneity or they may not. Perhaps you can construct examples in which they do. Fine. That wouldn't change Einstein's conclusion one iota, nor would it invalidate anything about SR. Clearly, he says that you need to know information about the observer's reference frame to determine the times of 2 events. And just as clearly, there are reference frames in which the timing of the lightning strikes will change in order. SR accounts for this, and classical notions do not.

Martin Miller

[russ_watters claimed:]
Einstein's experiment and yours are different.

[MM replies:]
How do they differ?

[russ_watters asked:]
Since its your experiment and your claim, why don't you
do the derivation instead of just asserting it over and
over again?

[MM replies:]
Because you keep raising your silly, irrelevant objection
over and over.

But I can easily close this simple case, as follows:

Let Observer A be at the origin of Frame A.
Let Observer B be at the origin of Frame B.
Let these two frames' x axes be parallel.
When these two frames' origins meet in passing,
let an explosive event occur at some point along
these frames' positive x axes. In the context of
SR, this explosion will occur at the same frame
point in both frames, which means that Xa = Xb,
which means that we can simply call this point X
for both frames. Indeed, since this explosive event
left its mark in each frame, the observers in each
frame can easily check where the event occurred after
the fact by looking for the burn marks left behind,
and these marks will be at the same x location in
each frame.

Case closed.

DrChinese

Not so fast.

Same example, add a couple of observers: C in A's frame at -X, D in B's frame at +X. Now C sees the explosion at a different time than A & B, as well as D. This is because the times in each reference frame are different. Besides, even in your example A & B witness the X explosion occurring at different times because one of them sees the event before the other (since they are in relative motion, they will not be co-located at each others' origin).

This effect is called the relativity of simultaneity, because the only way to get everyone to agree on the timing of events is to have them share information about each other's reference frames. If this were not necessary, then we would have absolute simultaneity - which we don't.

Case closed.

Martin Miller

[DrChinese noted:]
Not so fast.
Same example, add a couple of observers: C in A's frame at -X,
D in B's frame at +X. Now C sees the explosion at a different
time than A & B, as well as D. This is because the times in each
reference frame are different. Besides, even in your example
A & B witness the X explosion occurring at different times because
one of them sees the event before the other (since they are in
relative motion, they will not be co-located at each others' origin).
This effect is called the relativity of simultaneity, because the
only way to get everyone to agree on the timing of events is to have
them share information about each other's reference frames. If this
were not necessary, then we would have absolute simultaneity - which
we don't.
Case closed.

[MM replies:]
Ironically, you just confirmed the temporal portion of my little
experiment, even though no one was quibbling about that.

If you look back at my experiment, you will see that I was
counting on the _times_ being different.

But the _distances_ are the _same_.

Thus, light's speed in each frame was different, contrary to SR.

Case still closed, my way.

DrChinese

Why are you on this board if your purpose is to ignore facts? It has been demonstrated to you amply that in your example, it requires the observers to share information about their reference frames to get the anwer you desire. This would not be necessary in a world of absolute time. You are aware that the speed of light is always measured experimentally to be the same in any reference frame, and yet you make statements like the one above.

I would agree the case is closed, your way... because why would I want to waste my time going around in circles on a subject you don't want to learn about? Please enjoy your ego trip and the chance to make statements "your way". Revel in the thought that you are brilliant, and your line of reasoning is original. And by all means, please note that the physics establishment is blind and trying to keep your Nobel-worthy insights from seeing the light of day.

geistkiesel

Pardon this abrupt intrusion, but when reading the thread Iwas compelled to respond with the the following regarding synchronicity and verification of same:

Synchronizing clocks
What about the following synchronizing model: Two identical electronic clocks with any necessary resolution, or measured accuaracy, to what ever is level necessary to satisfy the constraints of the problem, are attached to two moving platforms on a steel track that is laser light engineered flat for 2000 km in each direction. The platforms begin to move in opposite directions from each other where the velocities are held constant by identical control pulses to each clock. The instantaneous location is measured within a wavelength of the light photons being emitted simultaneously in the stationary platform. The relativistic implication of length shortening and clock speed dilation are measurably zero at say 1 cm/second for a full journey time of 200,000 seconds for each clock.

Now sending a '0' signal along the attached wire start the clocks ticking. The output channels containing the measured clocks' readings are sent to the origin at regular intervals and both clocks send identical clocktimes in response to a single instance of two pulses directed at both clocks. That the clocks are running at the same speed is demonstrated by their synchronous output measured at the origin.

If this doesn't satisfy synchronicity and verification of the same, then at some instance a photon is directed at both clocks instantaneously from the origin. These photons arrive simultaneously back at the origin to within a wavelength of light after simply reflecting from mirrors on both clock platforms.We even have some calibrating to do perhaps to set the clocks such that the origin is their mutual midpoint. This procedure establishes the exact location of the clocks with respect to the origin which is guaranteed to be located at the midpoint of the clocks.

The fact of the constant velocity of light in what ever frame measured assures us the test photons are moving at the same velocity and travel the same distance in equal durations of flight time. What else is needed, contant temperature housings, correlations of signal during any direction the 4000 km track is pointing, atmospheric conditions minimized, what?

geistkiesel

1) Yes, If an Einstein gedunken experiment described in "Relativity" page 25 - 27 counts as an experiment then I can answer unambiguously Yes to 1). SR through the derived consequences of simultaneity loss predicts such loss for a moving platform that passes the midpoint of two photons emitted simultaneously from A and B with the movng platform located at the midpoint M of A nad B. The moving platform by detecting the light from the B source then the A source is hereby shown to necessitate the discarding of the concept of "simultaneity". The different arrival times lead the observer to conclude the photons were not emitted simultaneously.

2) No the prediciton was not correct.This is not the only possibility the moving observer can intitally make. She could observe that if she were moving the difference in the photons arrival on the moviong platform could result from the motion of the platform. Working backwards we can show the fallacy of this conclusion by clicking here.

Basically, the moving platform observer zeros her clock when passing the midpoint and measures t1', the instant the B photon arriives, and t2' the instant the A photon arrives. By making the assumption, to be tested, that she passed the midpoint of two emitted photons at M (where her clocks were zeroed) she ultimatey arrives at an expression t1' = (c-1)/2 = k. Comparing k with the measurd t1' proves simultaneity if t1' = k and one or the other photons was emitted first depending on the difference in t1' and k.

3)It is a gedunken experiment discussed in the literature with some repititon and depth.

4) No, see the link above.

Martin Miller

[DrChinese declared:]
You are aware that the speed of light is always measured
experimentally to be the same in any reference frame, and
yet you make statements like the one above.

[MM replies:]
Who's wasting whose time?

[MM continues:]
I say you are unless you can back up your above claim
with a date and names re the alleged experiment which
allegedly measured light's one-way speed between two
clocks.

[MM continues:]
Some Chinese doctors can sure cop an attitude.

Martin Miller

[geistkiesel wrote:]
Synchronizing clocks

What about the following synchronizing model: Two identical
electronic clocks with any necessary resolution, or measured
accuaracy, to what ever is level necessary to satisfy the
constraints of the problem, are attached to two moving platforms....

[MM replies:]
Clocks in different frames will almost certainly run at
different rates, and the difference will matter when
measuring light's speed.

Not to mention the fact that we need the synchronous clocks
to be in a single frame so we can use them to measure light's
one-way speed between them.

Did you know that no one has ever used two clocks in one
frame to measure light's speed? Have you ever wondered
why this is so?

russ_watters

It would surprise me if it hasn't been done, but if it hasn't, there's a simple reason: its redundant since both clocks say exactly the same thing.

wisp

Not so, if this test is done by a professional body it will kill off Einstein's SR in one go.
I can't think of anything more embarrassing than to find the fundamental pillar upon which modern physics bases many of its theories, has a dirty great crack in it.
The sooner this experiment is done the better. It is the most important challenge that SR has to face. I hope SR passes, but I think it will prove to be its undoing.

ahrkron

Physics experiments are currently taking care of much more delicate business. SR has been tested continuously and detailedly since 1905. Despite the wish of many that would like to "uncover the truth about SR", the theory is extremely well established due to its excellent agreement with experiment.

Currently, experimental physics is geared towards much different problems. SR is not an issue anymore. Current efforts have to do with many other aspects of the models we have for nature (CP violation, quark-hadron duality, high temp superconductors, dark matter, supersymmetry, etc.). The type of discrepancies between theory and experiment are clearly not coming from something as basic as SR. If that was the case, the discrepancies would be all over the place, QFT (which is based on SR) would not work, the Standard Model of particle physics wouldn't be able to predict with an 11-digit accuracy, and nobody would be able to hide it.

russ_watters

Why would two identical clocks sitting next to each other in the same frame show different times and what would that say about SR (besides 'we need better clocks to test SR...')?

Martin Miller

[Martin Miller wrote:]
Did you know that no one has ever used two clocks in one
frame to measure light's speed? Have you ever wondered
why this is so?

[russ_watters wrote:]
It would surprise me if it hasn't been done, but if it hasn't,
there's a simple reason: its redundant since both clocks say
exactly the same thing.

[MM replies:]
It has not been done, but not because of your reason; the real
reason is the fact that no physicist knows how to correctly
synchronize clocks.

-------------

[ahrkron declared:]
Physics experiments are currently taking care of much more delicate
business. SR has been tested continuously and detailedly since 1905.

[MM replies:]
Shall this urban legend never die?
Which part of SR has been tested?
Who has tested the basis of SR, namely, the light postulate?

No part of SR is testable because all parts of it are based
100% on a definition.

Every result of SR is a result of Einstein's definition of
synchronization, a mere convention given by man, and having
zilch to do with nature or physics.

For example, SR's "time dilation" or "clock slowing" is
merely an effect of Einstein's definition which relates
clocks incorrectly which in turn causes observers to see
a passing clock "run slow."

Here is how this happens, for those who need pictures:

passing clock
[3]-->
[3]------Frame A------[4]


------------------------[4]-->
[4]------Frame A------[5]

Although all three clocks really run at the same rate,
observers using Einstein's asynchronous clocks "see the
passing clock run slow."

SR per se has nothing to do with actual or real or physical
or intrinsic clock slowing because it does not even know how
to measure it. Also, Einsteinian observers in different frames
find different "rhythms" for the _same_ clock, whereas it is
physically impossible for one clock moving inertially to have
more than one intrinsic rhythm, so we know that SR does not
address or pertain to intrinsic clock rhythms.

And it is impossible to overstate the importance of getting
two clocks correctly related because all two-clock measurements
depend upon this, including light's one-way speed.