Sunday, August 05, 2012

So who's on first: Lorentz, Poincaré, or Einstein?


Tecumseh said...

More on this dispute. Somehow, none of these guys bothers to mention that Poincaré invented modern Topology around that time (1895-1904).

Tecumseh said...

Wiki has much more on this long-running dispute.

Arelcao Akleos said...

Ok, I don't see the follwoing mentioned in any of the articles you linked.
First, in terms of what we now know we can draw out of the mathematics. Fitzerald, then Lorentz, had set out the basic equations we associate with special relativity [those which we now label as the Lorentz Transformations, which superseded Galilean Relativity]. In Einstein's first paper, of 1904, he recapitulated these equations, but derived them with remarkable simplicity from a set of postulates on motion relative to the velocity of light. It was a philosophic masterpiece, and of great conceptual clarity [please read the papers of Lorentz, which developed these, as a basis of comparison]. More than this, though, it was Einstein's elucidation of the consequences of this which separated him from Lorentz, or Poincare'.
Lorentz, in his "The Theory of the Electrons and its Applications to the Phenomena of Light and Radiant Heat, had developed his transformational equations from a long and formal analysis upon Maxwell's equations, and had never set aside their interpretation in terms of the "Fitzgerald Contraction". The Einsteinian perspectives on "simultaneity" and on time are simply absent from Lorentz's work. It is mathematically, sound, but particular to certain classical assumptions on the electromagnetic theory.
Poincare' is mathematically more interesting [which is absolutely no surprise], and although he has no trace on the analysis of simultaneity or explicit acknowledgement of the central role of time, in terms of geometric technique you see many of the structures which soon enough Minkowski was to flesh out in rich detail [for special relativity].
It is not hard to imagine that Poincare' could have done what Einstein did, with special relativity, and even beyond, although from a more mathematical than physical/conceptual basis. But this is where Poincare's on work on philosophy led him to shoot himself through the gonads.
In a variety of writings, which are very well written and fun to read [see, for example, his Science and Hypothesis] Poincare' set out his thesis of "Conventionalism", in which different mathematical models of the phemomena may be equivalent in certain essential qualities but may differ in other respects. His thesis was that the "conservative" option would be to accept the model which least disrupts our "worldview". He explicitly mentions that one can modify the Newtonian worldview by accruing certain extra notions [such as, say, the Lorentz-Fitzgerald contractions] which would allow us to keep Euclidean Geometry as the basis of our mathematical analysis. He mentions that we could also 'save the phenomena' by adopting non-Euclidean geometry, but that the best "Convention" would avoid such a violation of our most basic "intuitions".
Einstein elegantly, and with great clarity and power, suggested the power of doing otherwise.
As for General Relativity [in the period from 1909 to say 1920] that was a very different story. In that one the arguments against the role of Einstein are much weaker, and only Hilbert stands as a possible rival...
That's a story for another day.

Mr roT said...

I still remember Einstein's Gedankenexperimenten for the derivations of Special relativity laws and the elevator Gedankenexperimenten for General relativity.
Those were the best days of my life, intellectually, and we did only Einstein all the way. No one gave a damn about Poincaré in the physics department, and rightly so. Also, as the pure mathy aspect was relegated to the Math department, the content of these theories was confined to the redneck Department of Physics.

I then took a course in the Math dept on the mathematics of General Relativity, taught by a famous geometer. That course was bullshit though the prof was great. I am still not convinced that he got the gist of the simple elevator Gedankens but his knowledge of differential geometry was encyclopedic. Problem was that the concentration was devoted to the tools, not the Nature, which is the real object of study. Einstein did not waste his time on that bullshit. These were the worst days of my intellectual life, in which I gave up on the Queen of Sciences to chase an unwilling, ugly handmaiden .

Mr roT said...

Deep thinking from wannabe Nazis.
Even David Duke would puke.

Mr roT said...

Fucking bullshit from the article, [About] "clocks in a moving frame showing the local time in that frame": "Einstein never had such an original and brilliant idea in his whole life." This is one of Einstein's postulates.

Note that this article links to in its first line of shit, i.e. its first line.

I smell a rat.

Tecs, you ought to eschew the ultra far right on matters of physics. For math, there's no danger because math doesn't really matter. This is fortunate as math departments are those in which psychotics do as well as, or better than, the rest of the population.

VCP, Tecs. I need to wash the smell of jackboots off my feet and legs.

Tecumseh said...

AA: Very interesting history-of-science lesson. You should write more on this stuff.

Mr Rot: It's a pity you don't appreciate Poincaré much. He's an outstanding figure. As for those bullshit links: just ignore that crap (I had not seen it).

Tecumseh said...

A historian reflects on the difficulties on settling this priority dispute. Here's the setup:

By 1905 Poincaré’s and Einstein’s reflections on the electrodynamics of moving bodies led them to postulate the universal validity of the relativity principle, according to which the outcome of any conceivable experiment is independent of the inertial frame of reference in which it is performed. In particular, they both assumed that the velocity of light measured in different inertial frames was the same. They further argued that the space and time measured by observers belonging to different inertial systems were related to each other through the Lorentz transformations. They both recognized that the Maxwell‐Lorentz equations of electrodynamics were left invariant by these transformations. They both required that every law of physics should be invariant under these transformations. They both gave the relativistic laws of motion. They both recognized that the relativity principle and the energy principle led to paradoxes when conjointly applied to radiation processes.

On several points—namely, the relativity principle, the physical interpretation of Lorentz’s transformations (to first order), and the radiation paradoxes—Poincaré’s relevant publications antedated Einstein’s relativity paper of 1905 by at least five years, and his suggestions were radically new when they first appeared. On the remaining points, publication was nearly simultaneous.

Mr roT said...

Tecs, sure Poincaré was a big guy, but as I remember it, von Neumann and Wigner were walking down a street when Wigner told von Neumann about a recent accomplishment of his in math physics.
Von Neumann kicked him in the shins with the reply,"What's that compared to E=mc^2?"
I don't think that any Topology would rate in the mind of a physicist.
Sorry about my frothing with hatred for the Nazis blathering on about Relativity while not knowing shit about the definitions.
In a rare point of agreement with AA, I have to back off on something that I have said and written many times. That is that philosophy is bullshit because there's no "it" in it. But the Gedankenexpriment method that Einstein (AA called his contributions philosophical) used to make whole theories out of a couple of innocuous assumptions about the general character of physical law looks a lot like how a philosopher thinks about things. That is, with not very much math.
Of course, Einstein has to deal with nonlinear PDE and pseudoriemannian geometry in General Relativity and that's kinda mathematical. But for Special Relativity, it's high school stuff.

Tecs, more about the Nazi relativists: These assholes were the punching bags du jour chaque jour while I was studying physics in earnest and so I have a Pavlovian response to that shit. I think these assholes should be handed to Iran.

My walk to Canossa is over, for now. Kick like hell now, you two!

Tecumseh said...

Von Neumann kicked him in the shins with the reply,"What's that compared to E=mc^2?"
Well, Poincaré had something to say about this -- before Einstein, who never credited Poincaré in his 1905 paper, by the way:

Like others before, Poincaré (1900) discovered a relation between mass and electromagnetic energy. While studying the conflict between the action/reaction principle and Lorentz ether theory, he tried to determine whether the center of gravity still moves with a uniform velocity when electromagnetic fields are included. He noticed that the action/reaction principle does not hold for matter alone, but that the electromagnetic field has its own momentum. Poincaré concluded that the electromagnetic field energy of an electromagnetic wave behaves like a fictitious fluid ("fluide fictif") with a mass density of E/c2. If the center of mass frame is defined by both the mass of matter and the mass of the fictitious fluid, and if the fictitious fluid is indestructible—it's neither created or destroyed—then the motion of the center of mass frame remains uniform. But electromagnetic energy can be converted into other forms of energy. So Poincaré assumed that there exists a non-electric energy fluid at each point of space, into which electromagnetic energy can be transformed and which also carries a mass proportional to the energy. In this way, the motion of the center of mass remains uniform.

Later on, Einstein resolved Poincaré's paradox (we could say, solved one of Poincaré's lesser-known conjectures), but again, without mentioning who formulated the framework for it:

It was Albert Einstein's concept of mass–energy equivalence (1905) that a body losing energy as radiation or heat was losing mass of amount m = E/c2 that resolved Poincaré's paradox, without using any compensating mechanism within the ether. The Hertzian oscillator loses mass in the emission process, and momentum is conserved in any frame.

Later on, it seems Einstein had some pangs of conscience, and gave some back-handed credit to Poincaré':

However, concerning Poincaré's solution of the Center of Gravity problem, Einstein noted that Poincaré's formulation and his own from 1906 were mathematically equivalent.

Yeah, right. How does "mathematically equivalent" differ from plain vanilla equivalent? Depends on what the definition of is is, I guess. Finally,

Einstein's first paper on relativity was published three months after Poincaré's short paper, but before Poincaré's longer version. It relied on the principle of relativity to derive the Lorentz transformations and used a similar clock synchronisation procedure (Einstein synchronisation) that Poincaré (1900) had described, but was remarkable in that it contained no references at all. Poincaré never acknowledged Einstein's work on special relativity. Einstein acknowledged Poincaré in the text of a lecture in 1921 called Geometrie und Erfahrung in connection with non-Euclidean geometry, but not in connection with special relativity.


Mr roT said...

As I was saying, the beauty of Einstein's approach, as far as I know, was in the clarity of his reasoning. I don't know any derivations of the laws of mechanics in the Special Relativity case or the General Relativity case other than those of Einstein himself.
Those proofs are perfect gems and to have them in one's head means understanding the principle completely As I have said a bit ago, I still remember the entire arguments, down to the names of the cartoon characters that my Prof used, "Uriah and Pete" having unprimed and primed coordinate functions, respectively. All of the arguments were given in terms of wavefronts of a point source of light which is on for an instant at some time $t_0$.

Shit that was great fun.