What does Einstein's special theory of relativity correctly predict and Poincare's relativity doesn't?

[Silvestru]

I know this has been discussed a bit, I myself was reading the article about the relativity dispute: https://en.wikipedia.org/wiki/Relativity_priority_dispute

I just wanted to understand maybe in greater detail, what did Pincare's theory not predict correctly, (except the E=mc^2 part,  which off course is no small detail). 

I am not asking about a comparison between the two (regarding reference times), I am asking what would the theory incorrectly predict.  

[Strange]

My understanding is that his mathematical description is entirely equivalent to Einstein's. The only difference being that he assumed the presence of an (undetectable) aether. 

https://en.wikipedia.org/wiki/History_of_special_relativity#Poincaré's_dynamics_of_the_electron

[Silvestru]

6 minutes ago, Strange said:

My understanding is that his mathematical description is entirely equivalent to Einstein's. The only difference being that he assumed the presence of an (undetectable) aether. 

https://en.wikipedia.org/wiki/History_of_special_relativity#Poincaré's_dynamics_of_the_electron

Einstein also didn't deny aether for a long time (citation probably needed) but a quote that has a pro and con argument to Poincare:

Quote

In 1889, ([Poi89]), Henri Poincaré argued that the ether might be unobservable, in which case the existence of the ether is a metaphysical question, and he suggested that some day the ether concept would be thrown aside as useless. However, in the same book (Ch. 10) he considered the ether a "convenient hypothesis" and continued to use the concept also in later papers in 1908 ([Poi08], Book 3) and 1912 ([Poi13], Ch. 6).

I mean, so what if he believed in an undetectable aether? To my current understanding it's the same as someone correctly formulating the law of conservation of energy for the first time and saying it is so because an undetectable God decided this. Then you "proving" that there is no God or that we don't need a God for that to work and getting all the credit for my law. (I understand I am exaggerating a bit with this last claim but it gets out what I mean).

 

6 minutes ago, Silvestru said:

Einstein also didn't deny aether for a long time (citation probably needed)

I take this back,  aether was proved to not exist long before Einstein drank his first coke: https://en.wikipedia.org/wiki/Michelson–Morley_experiment

[Strange]

55 minutes ago, Silvestru said:

I mean, so what if he believed in an undetectable aether?

I don't think it matters at all. And using it to argue whether or not he or Einstein "really" invented relativity theory is a bit pointless (angels on the head of a pin, stuff).

It just shows that science is a collaborative effort and the idea of the "lone genius" is (largely) an invention of the media. At worst, it just another example of Stigler's law of eponymy: https://en.wikipedia.org/wiki/Stigler's_law_of_eponymy (which is named after the wrong person).

1 hour ago, Silvestru said:

I take this back,  aether was proved to not exist long before Einstein drank his first coke

Although Einstein did, later, use the term aether to refer to space-time. (A fact that gets anti-relativity cranks every excited.)

[geordief]

If MM had discovered  aether then there would have been a value for it.

 

Since no discovery or value was made then  it seems possible that the latter could be either  vanishingly small or non existent

 

Would that "open verdict " keep  proponents of both models happy?

 

Would anything hang on one model being "more correct" than the other?

 

Btw this "spacetime can be considered an aether " idea seems  very wrong headed to me if spacetime is just a mathematical model....  (nothing curves any "fabric" of spacetime  does it-unless this fabric is actually this undetectable aether)

Edited April 4, 2018 by geordief

[Silvestru]

24 minutes ago, Strange said:

It just shows that science is a collaborative effort and the idea of the "lone genius" is (largely) an invention of the media. At worst, it just another example of Stigler's law of eponymy: https://en.wikipedia.org/wiki/Stigler's_law_of_eponymy (which is named after the wrong person).

Haha Stigler was a genius for this. I didn't know about him.

Quote

Stigler himself named the sociologist Robert K. Merton as the discoverer of "Stigler's law" to show that it follows its own decree

(I know you mentioned this but wanted to put the quote for others  )

[Strange]

1 minute ago, geordief said:

Btw this "spacetime can be considered an aether " idea seems  very wrong headed to me if spacetime is just a mathematical model.... 

I think he was just referring to the fact that space-time is everywhere in ... well, space-time! (Someone did point out that it was slightly more than that but the subtlety was rather lost on me). He did go on to make it clear that this use of the word aether was not supposed to indicate that there was any material substance involved.

[studiot]

It wasn't Poincare anyway.

 

Strange is correct they all did their bit, from Gauss to Riemann to Clifford

Quote

Clifford

On the Space theory of matter

Cambridge Philosophical Society proceedings2 1876

I hold in fact that

(1) Small portions of Space are of a nature analogous to little hills on a surface which is on average flat.

(2) That this property of being curved or distorted is continually being passed from on portion of Space to another after the manner of a wave.

(3) That this variation of the curvature of Space is really what happens in that phenomenon which we call the motion of matter whether ponderable or ethereal.

(4) That in this physical world nothing else takes place but this variation, subject possibly to the law of continuity.

 

I have emboldened the relevant phrase.

[geordief]

13 minutes ago, studiot said:

It wasn't Poincare anyway.

 

Strange is correct they all did their bit, from Gauss to Riemann to Clifford

 

I have emboldened the relevant phrase.

So Einsten was being bold when he claimed that he was the first to realize that spacetime could be curved?

I don't have his (E's)quote to hand but this Clifford seems to have tackled the concept  quite explicitly.

[StringJunky]

40 minutes ago, geordief said:

So Einsten was being bold when he claimed that he was the first to realize that spacetime could be curved?

I don't have his (E's)quote to hand but this Clifford seems to have tackled the concept  quite explicitly.

The bit that matters  is the maths and he probably put the meat on the bones by doing that.

[geordief]

5 minutes ago, StringJunky said:

The bit that matters  is the maths and he probably put the meat on the bones by doing that.

Yes , I was being a bit "cheeky"  but am still taken aback that the "hilly" concept was there ahead of Einstein. 

 

I can't see how Clifford came up with that(presumably on the shoulders of someone before him,though)

Edited April 4, 2018 by geordief

[Silvestru]

2 minutes ago, StringJunky said:

The bit that matters  is the maths and he probably put the meat on the bones by doing that.

Which maths StringJunky? 

It was assessed that Poincare's mathematical description of the special theory of relativity is entirely equivalent to Einstein's.

Oops, sorry I was mixing my op with GR

[studiot]

3 minutes ago, StringJunky said:

The bit that matters  is the maths and he probably put the meat on the bones by doing that.

 

Einstein was not a world class Mathematician, although no one surpassed his standing in Physics.

His liflong friend Grossman helped with much of the maths.

 

Willian Clifford , on the other hand, was one of the leading Mathematicians of his day ( a differential geometer to be precise just like our own ajb) and made many advances in his field.

Clifford algebras are named after hime and concern differential forms, the exterior calculus and stuff, which is only these days coming into its own in Physics and Engineering.

He, in his turn relied heavily on the pioneering work and insights of Riemann whos efamous Doctoral lecture kicked the whole thing off.

Gauss before hime had some insight, but didn't publish it all so we don't know how much he knew, but he was responsible for the original work on the geometric curvature of curves.

Poincare added his own theoretical work including the famous Poincare Conjecture, only recently proved by Perelman, in non-Euclidian geometry and the Poincare disk, which is one way to contain 'infinity'.

[Strange]

2 minutes ago, studiot said:

His liflong friend Grossman helped with much of the maths.

They collaborated on the development of the maths of GR. Grossman persuaded him that Riemannian geometry was the right way to go and mentored him when he was studying tensors. Some people (I'm sure not you) like to suggest he wasn't able to do the necessary maths himself.

9 minutes ago, studiot said:

Einstein was not a world class Mathematician, although no one surpassed his standing in Physics.

I don't know if he was "world class" but he was a very good mathematician. And was originally more interested in studying maths than physics.

"One of the many urban legends about the Relativity genius claims that Einstein failed mathematics at school. Nothing could be further from the truth: in fact, his grades in Algebra and Geometry were even better than in Physics."

https://www.bbvaopenmind.com/en/mathematics-and-albert-einstein/

"In 1935, a rabbi in Princeton showed him a clipping of the Ripley's column with the headline "Greatest living mathematician failed in mathematics." Einstein laughed. "I never failed in mathematics," he replied, correctly. "Before I was fifteen I had mastered differential and integral calculus." In primary school, he was at the top of his class and "far above the school requirements" in math."

http://content.time.com/time/specials/packages/article/0,28804,1936731_1936743_1936758,00.html

 

[MigL]

I'm gonna have to disagree, Studiot.
Special Relativity involves NO curvature.

It is widely accepted that Poincare was at most 5 yrs away from putting it all together and publishing his own Special Relativity.
He already had all the 'pieces' when Einstein beat him to it.

General Relativity, on the other hand, was a leap which might not have happened for a hundred yrs.
The 'pieces' were already there for almost a hundred years, since the time of Gauss , Boliay and Riemann, but the common belief was that Euclidian geometry governed the universe.
Einstein's leap in GR was the realization that a curved space-time geometry is a good description of gravity.
And as you said, the math was no easy task; even with Grossman's help, it took him years to get it right

[studiot]

6 hours ago, MigL said:

I'm gonna have to disagree, Studiot.
Special Relativity involves NO curvature.

It is widely accepted that Poincare was at most 5 yrs away from putting it all together and publishing his own Special Relativity.
He already had all the 'pieces' when Einstein beat him to it.

General Relativity, on the other hand, was a leap which might not have happened for a hundred yrs.
The 'pieces' were already there for almost a hundred years, since the time of Gauss , Boliay and Riemann, but the common belief was that Euclidian geometry governed the universe.
Einstein's leap in GR was the realization that a curved space-time geometry is a good description of gravity.
And as you said, the math was no easy task; even with Grossman's help, it took him years to get it right

 

Can't see what you are disagreeing about, perhaps you are smoking the wrong end of your cigar?

Nothing you say there is at variance with what I posted.

[MigL]

Sorry, I may have misunderstood you, then.
Carry on.