Re: Langevin's paradox again

Le 10/07/2024 à 12:42, Python a écrit :

Hachel’s posts are very naive”.

 It is not blunt, it is actually quite indulgent. On the other
hand Paul didn't have to suffer for thirty years of idiotic
posts from a demented M.D. from France.

Before insulting, we must be properly aware of the theses and postulates of those we want to refute.
Your position is to say anything, for the sake of anything, as long as it's fun.
For Paul, the logic is different, he is not here to have fun, he wants to know and teach, but the problem is that he does it very badly.
He posed a problem yesterday, proof that he is trying to progress; but the way he resolves it shows that if he studied Minkowski well, he did not study Hachel at all, and the result is catastrophic.
It poses the following problem (if I understood correctly since I only have part of the message):
A twin B is stationary with A (and even conjoined). Then it accelerates according to a=2ly/y² over a distance of 1 ly, before continuing in Galilean movement (it cuts the engine) then arriving at 9ly, it accelerates again, a=2ly/y² for 1 ly.
I don't really know what he is trying to do or demonstrate, but once again, I take the opportunity to point out my opposition to Albert Einstein when he says "relativity is very complicated calculations, but it There are no pitfalls." I say conversely: “Reltivity is at high school mathematics level once you have the right concepts, but it’s full of little traps”
It is obvious that because of this, Paul completely drowned in his answers.
We could also ask him the very profound question (if Doctor Hachel talks about it, and if Python wants to fight about it, it is because it is necessarily profound):
Is it the same thing for Paul at the level of observable time (in the frame of reference of A) if:
1. Subject B accelerates over one light year, spends 8 years in Galilean motion, then reaccelerates over one light year according to a=2ly/y²
and if
2. Subject B accelerates two light years, then spends 8 years in Galilean motion, regaining the speed it had after one light year of travel?
For Richard Hachel, proper times will be equal, but not improper times, which in this case may seem absurd if we believe that the two situations are identical in relativity.
N.B. Be careful, I did say in example 2 that traveler B resumes the Galilean speed which was his after 1 ly.
(we neglect the instantaneous deceleration or we imagine that he teletransports in another rocket that he passes)
It is obvious that otherwise, the Galilean phase will not be the same in the two examples, and that we are no longer in the question posed.
R.H.