Lorentz Einstein equivalence

Philosopher Laszlo E. Szabo writes in this 2010 paper:

It is widely believed that the principal difference between Einstein's special relativity and its contemporary rival Lorentz-type theories was that while the Lorentz-type theories were also capable of “explaining away” the null result of the Michelson-Morley experiment and other experimental findings by means of the distortions of moving measuring-rods and moving clocks, special relativity revealed more fundamental new facts about the geometry of space-time behind these phenomena. I shall argue that special relativity tells us nothing new about the geometry of space-time, in comparison with the pre-relativistic Galileo-invariant conceptions; it simply calls something else "space-time", and this something else has different properties. All statements of special relativity about those features of reality that correspond to the original meaning of the terms "space" and "time" are identical with the corresponding traditional pre-relativistic statements. It will be also argued that special relativity and Lorentz theory are completely identical in both senses, as theories about space-time and as theories about the behavior of moving physical objects. ...

They are not only “empirically equivalent”, as sometimes claimed, but they are identical in all sense; they are identical physical theories.

Consequently, in comparison with the classical Galileo-invariant conceptions, special relativity theory tells us nothing new about the spatiotemporal features of the phys-ical world. As we have seen, the longstanding belief that it does is the result of a simple but subversive terminological confusion.

He notes that others (including Einstein himself) have acknowledged that Lorentz's and Einstein's theories have the same empirical consequences, but conventional wisdom is that Einstein's special relativity is a superior theory. Szabo argues that they are really the same.

As I detail in my book, when Einstein's famous paper was published in 1905, no one thought that it was saying anything different from what Lorentz said years earlier. Not even Einstein claimed that it was different from the well-known Lorentz electron theory.

Szabo explains that in 1920 Einstein did try to argue that his special relativity was superior because he did not refer to the aether. But Szabo also notes that by 1920 Einstein himself was advocating existence of the aether.

My only disagreement with Szabo is that he sloughs over some historical details.

Though, it is a historic fact that Lorentz, FitzGerald, and Larmor, in contrast to Einstein, made an attempt to understand how these laws actually come about from the molecular forces.

Einstein's own story is that he tried to understand that, but he failed, and did not publish his attempts. Some people argue that Einstein's approach was superior because he did not publish such attempts, but that was not his view. Einstein thought that such a molecular explanation was important and desirable.

Szabo defines Einstein's special relativity as Minkowski's spacetime geometry:

In contrast, special relativity claims that the geometry of space-time is different: it is a Minkowski geometry M⁴.

(He said some similar things in a 2003 paper.)

Actually, Einstein completely missed this interpretation in his 1905 paper, and did not even understand it when Minkowski published it 3 years later. It is historically inaccurate to call this Einstein's theory.

32. Many of those, like Einstein himself (see Point 25), who admit the “empirical equivalence” of the Lorentz theory and special relativity argue that the latter is “incomparably more satisfactory” (Einstein) because it has no reference to the aether. As it is obvious from the previous sections, we did not make any reference to the aether in the logical reconstruction of the Lorentz theory. It is however a historic fact that, for example, Lorentz did.

No, it is not a historical fact. Lorentz mentions the aether only to explain why he was rejecting the aether drift theories. Einstein mentions the aether in 1905 to say that it is superfluous to his derivation. There is no significant difference between what Lorentz and Einstein said about the aether. My book has the details.

I do agree with Szabo's main point that support for Einstein's originality over Lorentz stems from a "subversive terminological confusion."