Did Lorentz or Einstein theoretically derive special relativity?

[zheng89120]

because it seems the Lorentz transformations constitute special relativity itself

 

[BruceW]

From what I heard, Einstein did not contribute much to the mathematics of special relativity, but it was him who made the big leap to use the maths to reformulate the laws of spacetime

 

[Dschumanji]

According to the book that Einstein wrote to explain the special and general theories of relativity to the layman:

But there are two classes of experimental facts hitherto obtained which can be represented in the Maxwell-Lorentz theory only by the introduction of an auxiliary hypothesis which in itself--i.e. without making use of the theory of relativity--appears extraneous.

It is known that cathode rays and the so called beta rays emitted by radioactive substances consist of negatively electrified particles (electrons) of very small inertia and large velocity. By examining the deflection of these rays under the influence of electric and magnetic fields, we can study the law of motion of these particles very exactly.

In the theoretical treatment of these electrons, we are faced with the difficulty that electrodynamic theory of itself is unable to give an account of their nature. For since electrical masses of one sign repel each other, the negative electrical masses constituting the electron would necessarily be scattered under the influence of their mutual repulsions, unless there are forces of another kind operating between them, the nature of which has hitherto remained obscure to us. If we now assume that the relative distances between the electrical masses constituting the electron remain unchanged during the motion of the electron (rigid connection in the sense of classical mechanics), we arrive at a law of motion of the electron which does not agree with expereience. Guided by purely formal points of view, H.A. Lorentz was the first to introduce the hypothesis that the form of the electron experiences a contraction in the direction of motion in consequence of that motion, the contracted length being proportion to the expression$$\frac{1}{\gamma}$$This hypothesis, which is not justifiable by any electrodynamical facts, supplies us then with that particular law of motion which has been confirmed with great precision in recent years.

The theory of relativity leads to the same law of motion, without requiring any special hypothesis whatsoever as to the structure and the behaviour of the electron.

...

[The following concerns the Michelson and Morley experiment]
Lorentz and Fitzgerald rescued the theory from this difficulty by assuming that the motion of the body relative to the aether produces a contraction of the body in the direction of motion, the amount of contraction being just sufficient to compensate for the difference in time mentioned above.

If I understand this correctly, it seems that Lorentz used his transformation to model the contraction of electrons as they moved at high speeds. He also used it to save the aether theory. Einstein's theory of special relativity applies to more than just electrons and rejects the idea of the aether. Lorentz was on the right track, he just didn't make that extra step that Einstein did.

 

[harrylin]

because it seems the Lorentz transformations constitute special relativity itself

According to Einstein's summary* in 1907, both of them did (Lorentz in 1904 and Einstein in 1905). He claimed not to have known Lorentz's 1904 paper (not to mention the one of Poincare!); but even if in fact he did know one or the other, his 1905 papers made important contributions to the development of the theory.

*http://www.soso.ch/wissen/hist/SRT/E-1907.pdf (sorry: in German)

 

[harrylin]

According to the book that Einstein wrote to explain the special and general theories of relativity to the layman:

If I understand this correctly, it seems that Lorentz used his transformation to model the contraction of electrons as they moved at high speeds. He also used it to save the aether theory. Einstein's theory of special relativity applies to more than just electrons and rejects the idea of the aether. Lorentz was on the right track, he just didn't make that extra step that Einstein did.

That only related to Lorentz's theory of electrons; the new theory (both Lorentz's and Einstein's accounts) applied to all matter and EM waves.

Note: I wonder why there is an issue about "who derived" SR, and not about "who derived" QM...

 

[PAllen]

That only related to Lorentz's theory of electrons; the new theory (both Lorentz's and Einstein's accounts) applied to all matter and EM waves.

Note: I wonder why there is an issue about "who derived" SR, and not about "who derived" QM...

Well, I see a combination of celebrity culture, media, and politics involved. Einstein got atypical acclaim, and was Jewish at a bad time. With QM, you got features named after people (Schrodinger wave equation, Heisenberg uncertainty principle, etc.). If the relativity theory as whole had a neutral name, in which there was the Lorentz transform, Einstein invariance principle, etc. vs. Einstein Theory of Relativity, there would presumably be much less obsession.

I guess also, though SR like QM was really developed by many people, Einstein's paper had an electric influence, more than any single QM paper. It was written for physicists, physically motivated, and collected everything into a coherent framework (whereas Poincare had tidbits in several papers, notes, and letters, often written more from the mathematical frame of mind).

 

[Zentrails]

because it seems the Lorentz transformations constitute special relativity itself

Einstein's miracle year paper on special relativity used simple geometry to establish the basic Special Relativity equations. He used the concept of an inertial frame of reference, but kept all the math within that frame, IIRC, negating the need for any mathematical transformations.

He did compare two different frames of reference and ask the thought question, what would be the geometry given the fact that observers in each frame measure the speed of light to be the same.

The math is actually quite simple. The old notion that "only a few people" understood Einstein's theory of Relativity certainly did not apply to Special Relativity, which Einstein admitted that shouldn't have included the word, "relativity."

Einstein was not a particularly good mathematician. Someone else had to point out to him that Rieman geometry would be apropos for his General Relativity theory.

He actually seemed to come up with his theories visually first, then looked for elegant mathematics to support it second.

 

[Dschumanji]

Einstein was not a particularly good mathematician. Someone else had to point out to him that Rieman geometry would be apropos for his General Relativity theory.

I've heard that this wasn't the case...

 

[GrayGhost]

According to the book that Einstein wrote to explain the special and general theories of relativity to the layman:

If I understand this correctly, it seems that Lorentz used his transformation to model the contraction of electrons as they moved at high speeds. He also used it to save the aether theory. Einstein's theory of special relativity applies to more than just electrons and rejects the idea of the aether. Lorentz was on the right track, he just didn't make that extra step that Einstein did.

Not exactly. Lorentz derived his transformations to force-fit the MMX null result. IOWs, to show the Fitzgerald contraction could be real. The assumption of an aether was prevalent then and Lorentz did assume it existed, so he built his model assuming such (apriori). Lorentz was on the right track only because he accepted that length contractions must exist. He was on the wrong track because he assumed all motion was relative to the aether frame. Yet amazingly enough, his transformations equations were correct, however they meant something different (from Einstein's).

Einstein assumed apriori that the 2 postulates were true. His LT derivation showed they were mathematically compatible, if true. It satisfied the MMX null result, w/o first assuming upfront that length contractions arose with relative motion. Einstein showed that the electron length-contracts "not because it shrinks in and of itself in an aether that never changes", but rather because the measure of space and time changes with a change in relative motion. So Einstein's LTs revealed a symmetry of space and time that is required assuming upfront that the 2 relativity postulates true, where no material body ever changes in and of itself no matter how it changes in its own state of motion.

GrayGhost

 

[JesseM]

Not exactly. Lorentz derived his transformations to force-fit the MMX null result.

Isn't length contraction alone enough to explain MMX, without time dilation or relativity of simultaneity? I thought Lorentz derived it as the transformation that would preserve Maxwell's laws of electromagnetism in different frames.

 

[GrayGhost]

Isn't length contraction alone enough to explain MMX, without time dilation or relativity of simultaneity?

Well, the assumption back then was isotropic light in only the aether frame. From the POV of an aether frame observer, I suppose one could show length contraction w/o time dilation. I don't see how one could do it from the Earth frame POV though, w/o invoking time dilation ... it seems to me that the explanation would have been incomplete.

I thought Lorentz derived it as the transformation that would preserve Maxwell's laws of electromagnetism in different frames.

Well, I'm sure that was the goal, yes. However, going in, said goal had to satisfy the Fitzgerald contraction predicted by the already verified MMX null result, while assuming a master aether frame. As you know, Einstein's approach satisfied the MMX null result w/o first assuming either a master aether frame or a Fitzgerald contraction.

GrayGhost

 

[harrylin]

Isn't length contraction alone enough to explain MMX, without time dilation or relativity of simultaneity? I thought Lorentz derived it as the transformation that would preserve Maxwell's laws of electromagnetism in different frames.

Yes indeed. Lorentz derived the equations (although not in the symmetrical form of Poincare as we know them today) in order to comply to the principle of relativity.

 

[JesseM]

Well, the assumption back then was isotropic light in only the aether frame. From the POV of an aether frame observer, I suppose one could show length contraction w/o time dilation. I don't see how one could do it from the Earth frame POV though, w/o invoking time dilation ... it seems to me that the explanation would have been incomplete.

Well, you could either just use the Galilei transformation for the Earth frame with the understanding that coordinate length was different than ruler length along the axis of motion relative to the aether, or you could come up with a new coordinate transformation such that coordinate length still matched ruler length in the Earth frame, if we say the aether frame is unprimed and the Earth frame is primed (and the aether is moving parallel to the x' axis of the Earth frame) it would just look like this:

x' = gamma*(x - vt)
y' = y
z' = z
t' = t

...then you could use this transformation to figure out how fast light moves in different directions in the Earth frame, given that it moves at c in all directions in the aether frame. Should then get the same prediction for the MMX in the Earth frame as you got in the aether frame, with no time dilation needed.

 

[ZealScience]

Lorentz transformation is actually from FitzGerald's answer to the Michelson-Morley experiment, and Lorentz summed them up. However Neither of them understand the meaning of the equations, it's Einstein who derived them and apply them to relativity which is not simply transformation. Even Lorentz himself praised that Einstein what hell of a genius!

 

[nitsuj]

because it seems the Lorentz transformations constitute special relativity itself

I think Einstien by leaps and bounds "theoretically derive[d] special relativity" before Lorentz (or anyone else for that matter). His intuition is remarkable even in the context of civilizations greatest scientists.

I forget where but I heard someone say "If I could ask Eistien one question it would be 'how did you know your thinking was on the right track?'"

So true, people everywhere think about this stuff and go off in some pretty fantastic directions, but Eistien was right. And pursued his intuition like he had read the theory from God's physics handbook.

Einstiens low profile may have helped keep him under the radar of other great minds of the time, so no direct competition. (I think with GR he did have some racing to beat him to the finish line, but from a mathimatical perspective)

A good story with a simular "who came up with it first?" Watson & Crick's pursuit of DNA (specificaly it's shape, solid proof), a very competitive race for sure.

 

[Zentrails]

I've heard that this wasn't the case...

I was speaking relatively. LOL

He was a far better mathematician than me or anyone I know, of course.
Just not as good as the top physics scientists he was competing with at the time.

 

[Zentrails]

I think Einstien by leaps and bounds "theoretically derive[d] special relativity" before Lorentz (or anyone else for that matter). His intuition is remarkable even in the context of civilizations greatest scientists.

I forget where but I heard someone say "If I could ask Eistien one question it would be 'how did you know your thinking was on the right track?'"

So true, people everywhere think about this stuff and go off in some pretty fantastic directions, but Eistien was right. And pursued his intuition like he had read the theory from God's physics handbook.

Einstiens low profile may have helped keep him under the radar of other great minds of the time, so no direct competition. (I think with GR he did have some racing to beat him to the finish line, but from a mathimatical perspective)

A good story with a simular "who came up with it first?" Watson & Crick's pursuit of DNA (specificaly it's shape, solid proof), a very competitive race for sure.

I agree and "track" is a good word to use, since there were trains and boats for mass transportation back then and that was it. So he visualized things mostly by thinking of trains, even more amazing when you think about it.

If I remember Watson's "Double Helix" book correctly, Watson & Crick were far ahead of their ONLY competitor (Linus Pauling) because Linus was convinced a triple helix was the correct structure. Watson's Cambridge group collaberated with Franklin's Kings college group, before which there were only 3 groups in the DNA "race."

Time sure have changed since then.

 

[homology]

I was speaking relatively. LOL

He was a far better mathematician than me or anyone I know, of course.
Just not as good as the top physics scientists he was competing with at the time.

We probably need to be careful to understand the times in which these folks worked. Things like group theory, operators, manifolds etc are common in physics now you'll see most of them at the undergrad level. But even the topic of matrices was not common among physicists at one time let alone functional analysis or differential geometry.

For example there's the following story about Gell-Mann (I'm just copying and pasting this from http://math.ucr.edu/home/baez/diary/march_2007.html" :

"Block is an expert on Lie algebras, and there's a fun story about him and Murray Gell-Mann, the physicists who one the Nobel prize for inventing "quarks". Actually quarks were part of a mathematical scheme which Gell-Mann called the Eightfold Way, because it was based on the 8-dimensional Lie algebra su(3).

The story goes like this:

Murray Gell-Mann's dream was to find a Lie algebra whose representations could model the observed baryons and mesons. A long time ago Heisenberg had invented a theory like this based on the Lie algebra su(2). This was able to account for baryons and mesons known at the time, but a lot more were discovered later. Gell-Mann knew this Lie algebra should contain the 3-dimensional Lie algebra su(2), since he wanted his theory to include Heisenberg's. In 1960 he worked on this problem for 6 months. He tried inventing 4-dimensional Lie algebras, then 5-dimensional ones, then 6-dimensional ones, then 7-dimensional ones... and gave up in disgust at this point, since nothing worked.

Then he talked to Richard Block, who is now a emeritus professor here at UCR, but was then an assistant professor at Caltech. Block told Gell-Mann that he'd been reinventing the wheel, and not doing a great job of it either: Élie Cartan had classified simple Lie algebras a long time ago, and after su(2) the smallest one is 8-dimensional, namely su(3).

Gell-Mann then invented the Eightfold Way.

I think that at the time, only 7 of the particles in the "meson octet" were known. The Eightfold Way said there should be 8, because su(3) is 8-dimensional. The missing meson — the eta — was discovered later"

 

[BruceW]

Love it when a plan comes together

 

[ZealScience]

I think Einstien by leaps and bounds "theoretically derive[d] special relativity" before Lorentz (or anyone else for that matter). His intuition is remarkable even in the context of civilizations greatest scientists.

I forget where but I heard someone say "If I could ask Eistien one question it would be 'how did you know your thinking was on the right track?'"

So true, people everywhere think about this stuff and go off in some pretty fantastic directions, but Eistien was right. And pursued his intuition like he had read the theory from God's physics handbook.

Einstiens low profile may have helped keep him under the radar of other great minds of the time, so no direct competition. (I think with GR he did have some racing to beat him to the finish line, but from a mathimatical perspective)

A good story with a simular "who came up with it first?" Watson & Crick's pursuit of DNA (specificaly it's shape, solid proof), a very competitive race for sure.

I don't quite agree with the fact, because lorentz transformation is from late 19th century (when Einstein was just a teenager), inspired by the famous michelson morley experiment, but paper on relativity starts around 1905. But lorentz himself didn't understand the lorentz transformation well, relativity to some extent explain the physics behind. So the famous Lorentz transformation should also be credited to Lorentz.

But Watson & Crick pursuit of DNA also is sort of contraversial considering the contribution from Franklin (a female biologist, Ican't remember the full name)

Another example, should be Mr Pauli, he seems to "borrowed" some ideas from others, but still he is known as a great scientist who contributes toward the exclusion principle.

But Einstein is certainly the only person in interpretating relativity for sure.

 

[Zentrails]

But Watson & Crick pursuit of DNA also is sort of contraversial considering the contribution from Franklin (a female biologist, Ican't remember the full name)

It's Rosalind Franklin.

 

[GrayGhost]

Well, you could either just use the Galilei transformation for the Earth frame with the understanding that coordinate length was different than ruler length along the axis of motion relative to the aether, or you could come up with a new coordinate transformation such that coordinate length still matched ruler length in the Earth frame, if we say the aether frame is unprimed and the Earth frame is primed (and the aether is moving parallel to the x' axis of the Earth frame) it would just look like this:

x' = gamma*(x - vt)
y' = y
z' = z
t' = t

...then you could use this transformation to figure out how fast light moves in different directions in the Earth frame, given that it moves at c in all directions in the aether frame. Should then get the same prediction for the MMX in the Earth frame as you got in the aether frame, with no time dilation needed.

Maybe so, but one would have an incomplete and incorrect model of nature.

Lorentz and Einstein obtained the same LTs. One assumes an invariant c in only the master aether frame, and the other assumes invariant c in any and all inertial frames. Now, I'm not very familiar with the Lorentz derivation, but here's the thing ... Einstein generates his linear coefficients alpha(v) and phi(v). He deterimines by logical deduction that phi(v)=1, and thus that aplha(v) = 1/beta(v) ... beta(v) being known as gamma(v) today. IOWs, Einstein did no force-fitting of group symmetries to obtain his transforms.

If I may ask you ... did Lorentz force-fit his coefficients to obtain the group symmetry that he (and Poincare) knew was required to ensure the principle of relativity, or did they naturally evolve as in the case of OEMB?

GrayGhost

 

[harrylin]

Maybe so, but one would have an incomplete and incorrect model of nature.

Lorentz and Einstein obtained the same LTs. One assumes an invariant c in only the master aether frame, and the other assumes invariant c in any and all inertial frames. Now, I'm not very familiar with the Lorentz derivation, but here's the thing ... Einstein generates his linear coefficients alpha(v) and phi(v). He deterimines by logical deduction that phi(v)=1, and thus that aplha(v) = 1/beta(v) ... beta(v) being known as gamma(v) today. IOWs, Einstein did no force-fitting of group symmetries to obtain his transforms.

If I may ask you ... did Lorentz force-fit his coefficients to obtain the group symmetry that he (and Poincare) knew was required to ensure the principle of relativity, or did they naturally evolve as in the case of OEMB?

GrayGhost

What do you mean with "force-fit"? Lorentz found by logical deduction that only a coefficient l=1 leads to the correct equations, and concludes:

The value of the constant must be unity, because we know already that, for w=0, l=1.

We are therefore led to suppose that the influence of a translation on the dimensions (of the separate electrons and of a ponderable body as a whole) is confined to those that have the direction of the motion, these becoming k times smaller than they are in the state of rest.

http://en.wikisource.org/wiki/Electromagnetic_phenomena

It's perhaps useful to point out that in 1904 he thus derived the Lorentz contraction from the PoR.

 

[nitsuj]

If I remember Watson's "Double Helix" book correctly, Watson & Crick were far ahead of their ONLY competitor (Linus Pauling) because Linus was convinced a triple helix was the correct structure. Watson's Cambridge group collaberated with Franklin's Kings college group, before which there were only 3 groups in the DNA "race."

Time sure have changed since then.

As you said, that is Watson's book you read.

 

[GrayGhost]

What do you mean with "force-fit"? Lorentz found by logical deduction that only a coefficient l=1 leads to the correct equations...

Thanx Harrylin. By force-fit, I meant "not by logical deduction, but rather by insertion". IOWs, if you assume you know the required final form of the equations to guarantee the PoR, you "make it happen" during derivation. From what you say, Lorentz obtained his linear coefficients by deduction, as Einstein did. I'll have to read thru his paper more closely.

Wrt the PoR ... Consider a dual pan balance whereby the line joining the pan midpoints are aligned with the balance's propagational path. Assume the pans are separated by a very long beam, and the wonder beam cannot bend. Further assume that "someone who believes himself at rest in Lorentz's master aether frame" records the balance's motion at luminal v thru the aether. Now, LET and SR produce the very same solns, so in either case, observers at rest with the balance should always witness the same result(s) ... ie, it's presumedly not possible to distinguish between SR & LET by experiement. Now, let's say 2 weights of identical mass drop from the sky, always of identical velocity and strike the balance pads AT ONCE "per an observer at rest with the balance". What would each theory predict wrt the balance beam tilting upon impact?

SR says ... the balance beam would not tilt.

LET (I think) would say ... the balance beam tilts, because the 2 weights do NOT strike the pads AT ONCE per an aether frame observer "if they strike the pads AT ONCE per the observer moving with the balance thru the aether". The aether POV is always right.

Wrt LET theory ... How is it that the PoR is upheld by LET theory? It seems to me that ... even though the LT results are the same in either case, they do not mean the same thing. The PoR "only appears to be upheld" (per LET) from a kinematic standpoint, but not with regards to force, and thus not with regards to energy. What is wrong with my reasoning here?

It's perhaps useful to point out that in 1904 he thus derived the Lorentz contraction from the PoR.

If all the coefficients were logically obtained by deduction, then I would agree. However, it just seems to me that the PoR is upheld kinematically, but not beyond that. How do you explain the scenario I pose above?

GrayGhost

 

[harrylin]

Thanx Harrylin. By force-fit, I meant "not by logical deduction, but rather by insertion". IOWs, if you assume you know the required final form of the equations to guarantee the PoR, you "make it happen" during derivation. From what you say, Lorentz obtained his linear coefficients by deduction, as Einstein did. I'll have to read thru his paper more closely.

How can one know what guarantees the PoR without first deriving it? Before 1904 Lorentz kept the unknown factor l in his discussions, leaving the question open if what we now call Lorentz contraction is indeed the right solution.

Wrt the PoR ... Consider a dual pan balance whereby the line joining the pan midpoints are aligned with the balance's propagational path. Assume the pans are separated by a very long beam, and the wonder beam cannot bend. Further assume that "someone who believes himself at rest in Lorentz's master aether frame" records the balance's motion at luminal v thru the aether. Now, LET and SR produce the very same solns, so in either case, observers at rest with the balance should always witness the same result(s) ... ie, it's presumedly not possible to distinguish between SR & LET by experiement. Now, let's say 2 weights of identical mass drop from the sky, always of identical velocity and strike the balance pads AT ONCE "per an observer at rest with the balance". What would each theory predict wrt the balance beam tilting upon impact?

SR says ... the balance beam would not tilt.

LET (I think) would say ... the balance beam tilts, because the 2 weights do NOT strike the pads AT ONCE per an aether frame observer "if they strike the pads AT ONCE per the observer moving with the balance thru the aether". The aether POV is always right.

Wrt LET theory ... How is it that the PoR is upheld by LET theory? It seems to me that ... even though the LT results are the same in either case, they do not mean the same thing. The PoR "only appears to be upheld" (per LET) from a kinematic standpoint, but not with regards to force, and thus not with regards to energy. What is wrong with my reasoning here?

If all the coefficients were logically obtained by deduction, then I would agree. However, it just seems to me that the PoR is upheld kinematically, but not beyond that. How do you explain the scenario I pose above?

GrayGhost

Probably you mean with "LET" Lorentz's 1904 paper, which Einstein summarized in 1907 together with his 1905 paper as the new theory that is based on the PoR (and which he later renamed "SR").
To be frank, I did not carefully read your example as any such discussion or paradox that I know of can be rephrased by replacing "aether" or "aether frame" by "rest frame". For a correct understanding of SR it is essential to realize that according to SR you may assume any inertial frame to be "truly in rest" so that the laws of nature should be valid wrt it, without any frame jumping.
Thus rephrased in interpretation-free SR:

"the 2 weights do NOT strike the pads AT ONCE per a rest frame observer if they strike the pads AT ONCE per the observer who is moving with the balance".

Note:a wonder beam that cannot bend cannot exist in SR

Harald

 

[Zentrails]

For a correct understanding of SR it is essential to realize that according to SR you may assume any inertial frame to be "truly in rest" so that the laws of nature should be valid wrt it, without any frame jumping.
Thus rephrased in interpretation-free SR:

"the 2 weights do NOT strike the pads AT ONCE per a rest frame observer if they strike the pads AT ONCE per the observer who is moving with the balance".

Note:a wonder beam that cannot bend cannot exist in SR

Harald

A non-accelerating frame of reference is all that is required for SR, which led Einstein to the next logical step and thought experiment - accelerating frames of reference and how the physics in them share many similarities with the physics inside a frame of reference fixed on the solid surface of a planet, or any non-solid surface where buoyancy is at equilibrium.

 

[GrayGhost]

harrylinn,

When one says "wonder beam", most folks generally accept that the beam does something that cannot happen in relality, or at least in practice to date. No different from discussing a wonder-traveler who attains c, which everyone knows cannot happen. But just for the sake of point, let's assume a wonder beam.

Well, I understand how SR handles my stated scenario. You skipped over that at first, and it remains clear that you are misreading it based on your prior response. I'm questioning the LET interpretation, that's all. As I said, I have not studied LET in any depth. If I may amplify my prior scenario a bit here ...

Assume a clock is attached to each always-inertial balance PAD, and they have been synchronized prior by the Einstein/Poincare synchronisation method.

SR says that the clocks are truly synchronised per those at rest with the balance, whereby the like-readouts are always simultaneous.

LET says that the clocks appear synchronised per those at rest with the balance, but are not truly simultaneous. An observer at rest in the aether frame disagrees that the moving PAD-clocks possesses the same time readout (ie they are not synchronised), and so they cannot be simultaneous when the 2 PAD-clocks possesses the same time readout, and the aether frame POV is always correct. Simultaneity is always dictated by only the aether POV.​

I know how SR works. Is my understanding of LET incorrect here? If so, it seems to me that "the PoR only appears to be upheld" under LET. That is, the balance beam would tip under LET, and the observer at rest in the aether frame would predict it. That is ... the balance should tip based upon simultaneous events, but not necessarily based upon like PAD-clock-time-readouts.

GrayGhost

 

[harrylin]

harrylinn,

When one says "wonder beam", most folks generally accept that the beam does something that cannot happen in relality, or at least in practice to date. No different from discussing a wonder-traveler who attains c, which everyone knows cannot happen. But just for the sake of point, let's assume a wonder beam.

A wonder beam creates a paradox in SR - just as a wonder signal at infinite speed. If you do want to discuss your paradox, please start a separate thread on that.

Well, I understand how SR handles my stated scenario. You skipped over that at first, and it remains clear that you are misreading it based on your prior response. [..]
GrayGhost

Sorry but evidently you did not understand my reply to you: According to the PoR the same laws of physics must be valid in any inertial frame, "ether" frame or not. Consequently, any problem that you imagine for "LET" is identical for standard SR, in which "ether frame" merely serves as a lable for a certain "rest frame". The laws of physics - even for moving balances (but not for wonder beams which break those laws) - must be valid wrt such a frame, as otherwise absolute inertial motion could be detected. The balance beam cannot tip according to the PoR, and both POV's must agree that the beam does not tip; that was the purpose of both Lorentz-1904 and Einstein-1905.

Note that in his 1904 paper Lorentz made one or two little errors, which made him unsure that the new theory perfectly obeyed the PoR; but that was soon straightened out by Poincare (and perhaps he answers your question clearer than I do!):
- http://en.wikisource.org/wiki/On_the_Dynamics_of_the_Electron_%28June%29

And for a primer to the light postulate and relativity of simultaneity, see (again!) a paper by Poincare (in XII and XIII, near the end):
http://en.wikisource.org/wiki/The_Measure_of_Time

 

[George Jones]

"Dismissing renewed attempts to deny Einstein the discovery of special relativity",

http://www.relatividadespecial.com/index.php?option=com_docman&task=doc_download&gid=24&Itemid=

 

[GrayGhost]

...

Harrylinn,

I never suggested any paradox exists. Far as the wonder beam simplication is concerned, if you prefer, you can simply assume it bends but does not break, and that there's nothing wonderful about it. I also never suggested that observers of differing frames would disagree as to whether the beam tips. I'm not sure where you get all this stuff, but you should really read posts more carefully before responding, because it just muddies the thread. What I was asking about was (1) did Lorentz force-fit his LT derivation to accommodate the PoR (you say no), and (2) does the PoR truly apply to the all-of-physics under LET, or does it apply only kinematically? From your last post, it seems that it applies period.

LET an SR are not the same theory. Some folks here claim that the theories are identical, except that any aether frame is superfluous per SR, and that it's impossible to detect the truly existent aether frame per LET. Light speed is defined differently per each theory. One theory says that what you measure matches what is real, while the other says length-contractions prevent your contracted ruler from measuring the true-contractions. It seems to me that there is more a difference between the 2 theories than these alone. Lorentz disagrees that 2 inertial clocks synchrionised-with-each-other moving thru the aether are "truely simultaneous" per themselves. Is this correct, or not?

GrayGhost

 

[Sybren]

As far as I know, Lorentz invented his transformations to account for the result of the Michelson-Morley interferometer experiment, in case of a luminiferous ether. The experimental setup was moving through the ether, he said, and it may possibly be a yet unknown property of electrons that they contract in the direction they are moving in through the ether. This would deform the interferometer setup in the right way to produce the observation. What he did here was come up with the necessary mathematical relation if you accept the experimental outcome, and accept the ether concept.

Einstein knew nothing about this experiment, and was studying Maxwell's equations, when he was considering the problem of a moving magnet and a conductor (moving magnet and conductor problem). When using Galilean transformations between the magnet frame and the conductor frame, the normal procedure at that moment, the calculated Lorentz force an an electron was identical in both cases. However, the electromagnetic fields producing the force were different. Although the Galilean transformation conserved the Lorentz force in this case, it did not conserve the Maxwells equations (as seen by substituting the Galilean-transformed fields into the Maxwell equations). At this point, it can be shown (I yet have to complete this part of the derivation) that there exists a transformation (non-Galilean) that conserves Maxwell's equations as well as the Lorentz force in both frames. This transformation equation is, in fact, the Lorentz transformation equation.

 

[PhilDSP]

LET an SR are not the same theory. Some folks here claim that the theories are identical, except that any aether frame is superfluous per SR, and that it's impossible to detect the truly existent aether frame per LET.

I think I agree with you on those points. If you don't delve into either the mathematics or the rationale of development deeply enough it seems reasonable to view the observables as equivalent, but that may be deceptive. Lorentz's theory is built around the concept of the invariance of the wave operator and the spatial deformation of an extended electron charge. It doesn't make any ad hoc postulates that force a redefinition of the metric relationships between space and time. It isn't necessarily limited to inertial frames and is therefore potentially more encompassing from a mathematical point of view, even to the point of potentially making an absolute frame of reference observable.

 

[Histspec]

What I was asking about was (1) did Lorentz force-fit his LT derivation to accommodate the PoR (you say no), and (2) does the PoR truly apply to the all-of-physics under LET, or does it apply only kinematically?

Maybe one has to look at the predictions of various kinematic and dynamic test theories of SR:

http://en.wikipedia.org/wiki/Test_theories_of_special_relativity"

For example, the Robertson-Mansouri-Sexl theory is a kinematic framework. Giving to the test-parameters their relativistic values, then (and only then) this "preferred frame theory" is experimentally indistinguishable from SR.
It becomes a little more complicated, when one uses more extensive test theories like the

http://en.wikipedia.org/wiki/Standard-Model_Extension" .

This model includes a bunch of parameters, which also apply to dynamics. Of course, also in this model, a suitable combination of the parameters leads to a "preferred frame theory" experimentally indistinguishable from SR, but the probability of such a theory is extremely small due to the large number of ad hoc hypotheses required.

So, in summary: I think it's always possible to modify "LET" so that it is experimentally equivalent to SR. However, the increasing number of effects that must be explained, decreases the probability of such a theory.

Regards,

 

[harrylin]

Harrylinn,
I never suggested any paradox exists.
[..] I also never suggested that observers of differing frames would disagree as to whether the beam tips.

Indeed it was not you but me who suggested that your example is a paradox (=apparent contradiction): I actually understood that according to you, "the observer at rest in the aether frame would predict" that "the balance beam would tip", while according to "observers at rest with the balance" "the balance beam would not tilt". Sorry that I misunderstood you.

That would be perfectly incompatible with Poincare's 1905 summary to which I gave a link:

Lorentz [managed to] bring [his hypothesis] into accord with the postulate of the complete impossibility of determining absolute motion [..] in his article entitled Electromagnetic phenomena in a system moving with any velocity smaller than that of Light (Proceedings de l’Académie d’Amsterdam, May 27, 1904).

[...] LET an SR are not the same theory.
Some folks here claim that the theories are identical, except that any aether frame is superfluous per SR, and that it's impossible to detect the truly existent aether frame per LET. Light speed is defined differently per each theory. One theory says that what you measure matches what is real, while the other says length-contractions prevent your contracted ruler from measuring the true-contractions. It seems to me that there is more a difference between the 2 theories than these alone. Lorentz disagrees that 2 inertial clocks synchrionised-with-each-other moving thru the aether are "truely simultaneous" per themselves. Is this correct, or not?
GrayGhost

As I already mentioned, according to Einstein a new theory emerged with the writings of Lorentz in 1904 and his own in 1905; I agree with that. However there is a subtle difference between the two interpretations of the theory: whereas Lorentz found it useful to distinguish between what appears to happen and what "really" happens from an unknown perspective that cannot be detected, Einstein found it better to only discuss the phenomena (=appearances, not what "truly" happens!).