Monday, April 2, 2012

Einstein did not refute Lorentz

A reader comments that Einstein could have had some "imaginative leap" that allowed a better interpretation of the aether.

If Einstein had some disagreement with Lorentz, he had plenty of opportunities to say so. Einstein's famous 1905 relativity paper makes three references to Lorentz's work:
They suggest rather that, as has already been shown to the first order of small quantities, the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good. ...

If we imagine the electric charges to be invariably coupled to small rigid bodies (ions, electrons), these equations are the electromagnetic basis of the Lorentzian electrodynamics and optics of moving bodies. ...

Since ..., we have the proof that, on the basis of our kinematical principles, the electrodynamic foundation of Lorentz's theory of the electrodynamics of moving bodies is in agreement with the principle of relativity.
The first sentence does not mention Lorentz's name, but Einstein always explained it as referring to Lorentz's 1895 paper.

As you can see, Einstein agrees with Lorentz on all points. The 1905 paper has two postulates, the relativity principle and the constant speed of light. The first is explicitly taken from Lorentz, as quoted above. The second was also borrowed from Lorentz, as Einstein later explained.

Einstein had another chance to clarify his relationship to Lorentz's theory in 1907, when he was invited to write a relativity review paper, published in 1908 (also here), regurgitating his 1905 paper along with some other work. It said:
In what follows it is endeavored to present an integrated survey of the investigations which have arisen to date from combining the theory of H.A. Lorentz with the theory of relativity.

In the first two parts of this work are treated the kinematic foundations of the theory of relativity and their application to the basic equations of teh Maxwell-Lorentz theory; I am following here the investigations of of H.A. Lorentz (Versl. Kon. Akad. v. Wet., Amsterdam 1904), and A. Einstein (Ann. d. Phy. 16, 1905). [translation by H.M. Schwartz, 1976.]
Einstein always denied that he had read that 1904 Lorentz paper before 1905, in spite of the similarity of ideas, and of evidence that he had access to Lorentz's results. But regardless, Einstein acknowledges Lorentz's 1904 paper in 1907, and acknowledges the similarity with his own work. Einstein does not express any disagreement with Lorentz.

Einstein does not express any disagreement with Poincare either, as Poincare had also published a version of relativity theory.

Lorentz published his 1906 Columbia U. lectures on relativity, where he described Einstein's work without expressing any disagreement with it. That is where Lorentz says, "Einstein simply postulates what we have deduced". After praising Einstein's simplicity, he says, "Yet, I think, something may also be claimed in favor of the form in which I have presented the theory." Lorentz was saying that he and Einstein had different ways of presenting the same theory, with advantages and disadvantages to each approach.

Minkowski's 1908 paper says how he goes farther than Lorentz and Einstein:
This hypothesis sounds rather fantastical. For the contraction is not to be thought of as a consequence of resistances in the ether, but purely as a gift from above, as a condition accompanying the state of motion.

I shall show in our figure, that Lorentz's hypothesis is fully equivalent to the new conceptions about time and space, by which it becomes more intelligible. ...

But the concept of space was not altered, either by Einstein or Lorentz, ...
That's right. Lorentz and Einstein had the formulas that are equivalent to special relativity, but it was Poincare and Minkowski who formulated the geometric interpretation that altered the concept of space.

Poincare praises Lorentz, but is not afraid to express disagreement. Poincare's 1900 paper says:
It would no doubt seem strange that in a monument raised to the glory of Lorentz I would review the considerations which I presented previously as an objection to his theory. I could say that the pages which follow are rather in the nature of an attenuation rather than a magnification of that objection.
Poincare's long 1905 paper says:
The importance of the question determined me to take it up again; the results which I obtained are in agreement with those of Lorentz on all important points; I was only led to modify and supplement them in some points of detail; one will further see the differences which are of secondary importance.
Einstein fans like to say that he somehow reversed some faulty view of Lorentz and/or Poincare, but they are never able to explain why Einstein himself was never able to articulate such an opinion. Was he too stupid to realize what he had done? Was he too cowardly to say that someone else was wrong? Were his communication skill insufficient to say what he wanted to say? No, it is much more likely that he simply had no disagreement with Lorentz or Poincare. He did not even understand Poincare.

1 comment: