Monday, January 8, 2024

Remembering Voigt in the Relativity Priority Dispute

From a 2019 paper on the origin of special relativity:
Voigt transformations in retrospect: missed opportunities? ...

Nearly two decades before the vigorous development of special relativity has started, in 1887 Woldemar Voigt published an article on the Doppler effect in which some fundamental principles underlying the relativity theory were anticipated. Namely, he was the first who used Einstein’s second postulate (universal speed of light) and the restricted form of the first postulate (invariance of the wave equation when changing the inertial reference system) to show that the Doppler shift of frequency was incompatible with Newtonian absolute time and required a relative time identical with the Lorentz’s local time introduced later.

Voigt's paper was not appreciated. The paper moves on to "the pointless Einstein-Poincar´e priority dispute."
In particular we are interested in to find out why the role played by Poincar´e was not properly acknowledged at that time by his contemporaries. Our hypothesis is that this happened because Poincar´e’s approach required a higher level of mathematical education than the majority of physicists had at that time. Minkowski belonged to a few who were in a position to duly appreciate Poincar´e’s contribution.
Poincare and Minkowski died in the next several years, so that partially explains why they did not take part in a priority dispute with Einstein. The paper acknowledges that Einstein lied about his sources all his life.

Many credit Einstein for discovering clock synchronization and the relativity of simultaneity in 1905, but that is clearly false:

Already in 1898, “Poincar´e had presented exactly the same light signaling and clock synchronization thought experiment that would later be found in Einstein’s 1905 relativity paper” [19], although Poincar´e’s presentation is without any mention of the relativity principle and Lorentz’s local time. Two years later in his lecture “Lorentz’s theory and the principle of reaction” Poincar´e used his light signaling and clock synchronization thought experiment to explain the physical meaning of the Lorentz’s local time [19]. ...

In 1902 letter to the Nobel committee to nominate Lorentz for the Nobel prize in Physics, which he indeed was awarded, Poincar´e praises very highly Lorentz’s “most ingenious invention” of “local time” and writes: “Two phenomena happening in two different places can appear simultaneous even though they are not: everything happens as if the clock in one of these places were late with respect to that of the other, and as if no conceivable experiment could show evidence of this discordance” [19].

Minkowski was the much bigger influence on acceptance of relativity:
Minkowski’s September 21st, 1908, lecture “Space and Time” was a crucial event in the history of relativity 1. ...

The influence of the Cologne lecture was enormous. Its published version “sparked an explosion of publications in relativity theory, with the number of papers on relativity tripling between 1908 (32 papers) and 1910 (95 papers)” [31]. The response to the Minkowski’s lecture was overwhelmingly positive on the part of mathematicians, and more mixed on the part of physicists — only in the 1950s their attitude began to converge toward Minkowski’s space-time view [31]. ...

However, in our opinion, to make the decision to exclude Poincar´e’s name from the Cologne lecture Minkowski needed some serious reason to psychologically justify such an unfair omission.

The geometry of special relativity was only appreciated by mathematicians:
A surprising fact about Minkowski’s “Raum und Zeit” lecture is that it never mentions Klein’s Erlangen program of defining a geometry by its symmetry group [27]. A link between Minkowski’s presentation of special relativity and Erlangen program was immediately recognized by Felix Klein himself [116] who remarked: “What the modern physicists call the theory of relativity is the theory of invariants of the 4-dimensional space-time region x, y, z, t (the Minkowski ’world’) under a certain group of collineations, namely, the ’Lorentz group’ ”. Untimely death of Minkowski presumably hindered the appreciation of this important fact by physicists.
It concludes:
In parallel to the advance in modern physics, in the middle of the twentieth century it became increasingly evident that Poincar´e’s contribution to relativity was unjustly downplayed. As a result, some attempts to restore the justice followed. ...

Most succinctly this difference was expressed by Lorentz himself: ‘the chief difference being that Einstein simply postulates what we have deduced, with some difficulty, and not altogether satisfactorily, from the fundamental equations of the electromagnetic field” [133].

Poincar´e’s objective was much more ambitious than Einstein’s as he wanted to derive special relativity as an emergent phenomenon. It is quite possible therefore that Poincar´e simply considered Einstein’s contribution as being too trivial in light of this bigger goal. “To Poincar´e, Einstein’s theory must have been seen as a poor attempt to explain a small part of the phenomena embraced by the Lorentz theory” [135].

There is still another aspect which makes Einstein-Poincar´e priority dispute pointless. Modern understanding of relativity is significantly different from the one that was cultivated at the beginning of the twentieth century. Two examples are the notions of æther and relativity of simultaneity which are often used in the priority dispute. ...

Usually this stubbornness of Poincar´e with respect to the æther is considered as his weak point, as an evidence that he didn’t really understand relativity. It is historically true that the abolishment of the æther by Einstein played a crucial role and revolutionized physics. However, frankly speaking, in retrospect, when this revolution came to its logical end in modern physics, we can equally well consider Poincar´e’s attitude as prophetical.

As modern physics has progressed in the twentieth century, it became increasingly evident that the vacuum, the basic state of quantum field theory, is anything but empty space. In fact, at present an æther, “renamed and thinly disguised, dominates the accepted laws of physics” [141]. It is clear that only “intellectual inertia” [142] prevents us from using historically venerable word “æther” instead of “vacuum state” when referring to the states with such complex physical properties as vacuum states of modern quantum theories.

Poincar´e proponents in the priority dispute argue that Einstein synchronization, which Einstein himself considered as the crucial element of special relativity, has in fact originated from Poincar´e’s work.

In light of this immense and still continuing progress of modern physics, attempts to retrospectively induce an artificial Poincar´e-Einstein priority dispute and rewrite the history seem minute. We will be happy if this arid and futile dispute will come to its end. There is nothing scientific in it and its presence only emphasizes hideous traits of human nature.

Did the authors of this paper think that they were going to write the last word on the subject?

This paper is convincing that Lorentz and Poincare had all of relativity theory before Einstein, that Einstein lied about his sources to get more credit for himself, and that in retrospect the Poincare-Minkowski view was superior to Einstein's.

However the authors think that it is unfair to judge Einstein in retrospect, as no one could have known which ideas would be more important later. It took 50 years, the authors say, for the Physics community to come around to the Poincare-Minkowski geometric view. The paper puts a lot of weight on the opinion of Max Born, who was a friend of Einstein, and who was greatly influenced by Einstein's 1905 paper. But there is not much substance to Born's opinion. Many people are greatly influenced by a textbook, but that does not mean that the textbook is original. While Born was a relativity expert, it is not clear that he understood Poincare's papers.

I might agree that the priority dispute is tiresome and settled, except that the Physics community continues to idolize Einstein as the greatest genius ever, for how he discvoered relativity. For example, see this recent Discover magazine list of the ten greatest scientists of all time, where Einstein is number one, mainly for relativity work. (Three of the other nine are women, but that is another story.)

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