Help Historical evolution of understanding of SR

[bernhard.rothenstein]

special relativity history

I would venture that the evolution in SR you refer to is more a change, or improvement if you prefer, in mathematical formalism than an actual change in the theory. That and an evolution in language.

I think that the history of special relativity is related with the physical meaning of the speed of light: infinite, finite, finite and invariant.

 

[Anonym]

he obviously refers to the Galilean Principle of Relativity of Newtonian mechanics, which he extends to electrodynamics..

I think that you give precise explanation of the role and meaning of the par. 1. That is what I tried to explain to JustinLevy. I understand JesseM (post #2) said the same. I am not expert in linguistic but the translation without “good” or “well” seems to me better (simply: … will be valid for all frames of reference for which the equations of mechanics hold.).

I don't know if you might gain any deeper insight in whatever you're debating.

I don’t know either yet. By the way, we didn’t discuss the formulation in the par.2. I prefer the one given by L.D. Landau and E.M. Lifsheetz (“Field Theory”): There exists the upper bound of the velocity of the propagation of the interactions. The rest is deduced (Minkowski interval).

However, formulation in the par.1 I still consider poetry. I think that it is impossible to give the independent formulation of the Principle of Relativity outside the language of the theory of continuous groups and the differential geometry (math definition of the reference frames). To enforce my statement, it is the fundamental principle of the Theory of Measurements and has nothing to do with dynamical laws. We know that the axiomatic introduction of the internal degrees of freedom allow rediscovering the connection and thus the external and internal degrees of freedom appear democratically. All that was done by H.Weyl, E.P.Wigner and C.N.Yang. I guess that the proper extension of the ref frames into the quantum domain exists.

Regards, Dany.

P.S. “you dropped the dative case some thousand years ago”. What you have in mind?

 

[Ich]

I am not expert in linguistic but the translation without “good” or “well” seems to me better (simply: … will be valid for all frames of reference for which the equations of mechanics hold.).

I think "hold good" means exactly the same as "is valid"; in any case, that's what Einstein wrote.

I think that it is impossible to give the independent formulation of the Principle of Relativity outside the language of the theory of continuous groups and the differential geometry (math definition of the reference frames).

I've read several operational definitiions, and even though I never checked thoroughly I'd expect such a definition to be possible.

P.S. “you dropped the dative case some thousand years ago”. What you have in mind?

That was an irrelevant and offtopic remark. I just found it impossible to translate the sentence without changing its grammar, because there is no dative in English. Old English still had it.

 

[Anonym]

I've read several operational definitiions, and even though I never checked thoroughly I'd expect such a definition to be possible.

Please, give me a refs on that definitions. I use N.A.Doughty “Lagrangian Interaction”, Addison-Wesley, 1990. See par. 9.5-9.7 (p.197-201) especially.

Regards, Dany.

 

[Ich]

Please, give me a refs on that definitions.

There was sort of a misunderstanding on my side. I meant definitions of an inertial system.

Given an inertial system, it is easy to state that in every single one of them, every internal experiment gives the same results. Is that enough?

 

[Anonym]

I meant definitions of an inertial system.

Given an inertial system, it is easy to state that in every single one of them, every internal experiment gives the same results. Is that enough?

I must admit that I lost you completely. I don’t know how you define an inertial system. I don’t know what it means internal experiment.

The difference that is "Lost in Translation" is that he obviously refers to the Galilean Principle of Relativity of Newtonian mechanics, which he extends to electrodynamics. The whole thing about laws that hold good here or there is merely a restatement of that, not more. It obviously did not occur to (or did not bother) Einstein, that the reinvents said laws a few pages later. Really "you know what I mean" on his side, as I perceive it.

My problem is that I don’t know what he meant and what did bother him. But I know what I mean: how the Galilean Principle of Relativity of Newtonian mechanics or SR should be extended to quantum fields domain? What is the adequate conserved quantity- Noether charge or universal Poincare invariant?

About good or bad here or there I know that “There is nothing either good or bad. Thinking makes it so.” And I don’t believe that A.Einstein disagree with that.

Regards, Dany.

 

[Anonym]

Perhaps, it is worth to add something. OP question seems simple and innocent: what was known at 1905 and how SR is treated 100 years later.

However, eventually the discussion was around the completely different topic: what is the axiomatical foundation of SR, namely, whether A. Einstein first and second postulates should be considered independent and how the discrete symmetries are included.

That I consider the most fundamental questions of modern physics that require at least another 100 years of development to be answered.

Regards, Dany.

 

[Ich]

I must admit that I lost you completely. I don’t know how you define an inertial system. I don’t know what it means internal experiment.

Well, I did lose you, too. I'm more the simple-minded one, it's ok to me if they define operationally what an inertial frame is and what the first postulate means. All poetry, of course, but enough for me.
It occurs to me that I didn't really help to answer the OP's question, whatever it was, so I better withdraw.

 

[Anonym]

All poetry, of course, but enough for me.

It was poetry at 1905 (É.Galois, N.Abel, and S.Lie). It is not poetry anymore after E.Cartan, H.Weyl, E.P. Wigner, C.N. Yang and R.Utiyama.

It occurs to me that I didn't really help to answer the OP's question, whatever it was.

But you, JesseM and Pervect did help me. The independence of A.Einstein extension of Copernicus/Galileo Postulate of Relativity was so self-obvious to me that I missed completely the point. The quick look check provided the following results:

1)A.Einstein, “The Evolution of Physics”, (1938): Yes, independent;
2)E.P. Wigner, “Unitary Representations of the Inhomogeneous Lorentz Group Including Reflections” (1962): Yes, independent;
3)L.D.Landau, “Field Theory” (1960): No, contained in the second postulate;
4)R.P.Feynman, “The Feynman Lectures on Physics” (1963): No, contained in QT.

E.P.Wigner:” Into the second category falls our knowledge of the “laws of motion” which tell us how to foresee the future state of the World, assuming that we know the present state. These laws, we are convinced, are exact, of almost unbelievable precision, and of a beauty and simplicity which is much greater and deeper than any that we could have invented.

This sharp division of our knowledge and even of the knowable is strange enough. It is stranger yet to assume that the laws of motion have a structure themselves, that they conform with some general principles which, though they do not determine the laws of motion, do impose certain restrictions on them. Further, these superprinciples are so much easier to divine than the laws of motion themselves that we in fact know sufficiently many of them.”

And the famous question of A.Einstein:”What really interests me is whether God had any choice in the creation of the world.”

Both are talking about what is known in Geometry as the set of the Principal Postulates. I consider their analog in Physics the following:

1)Postulate of Unitarity: determination of the Physics as the general theory of fields-W.R.Hamilton and E. Schrödinger wave mechanics;
2)Postulate of Communication/Causality: physical determination of geometry;
3)Postulate of Relativity: definition of the action and the inertial systems, determination of the connection between the physics and geometry (for example, eq. (8.1) in L.D. book referred above - definition of the free motion);
4)Postulate of Local Gauge Invariance: determination of the fundamental interactions (mutually interacting physical systems);
5)Postulate of Least Action: determination of the dynamical behavior of the physical system (physical analog of the Fifth Postulate).

Thus the answer to A. Einstein question is Yes.

I claim that the presented set is a complete set. And it is the only possible absolute result in Physics.

The completeness will be verified by the actual realization the unification of all fundamental interactions program. The Postulate of Relativity is an origin, cradle of modern physics. Does the question whether it exists independently or is derivable from the other four remind you something? The completeness will be proved through the attempts to reduce it.

Thank you all.

Regards, Dany.