Re: Langevin's paradox again

Le 10/07/2024 à 20:56, "Paul.B.Andersen" a écrit :

Den 09.07.2024 15:47, skrev Richard Hachel:

The paradox is this: The greatest relativistic physicist in the universe (Richard Hachel) said that the effects of physics are reciprocal by permutation of observer, and therefore, if we take the INTERNAL mechanism of two watches, each will beat faster than the other, both on the outward and return journey, or during a long circular journey.
 

 A very naive notion. 😂

This is not a naive notion but a notion that is difficult to understand when you don't have the key, and which has posed problems for many physicists for 120 years.
At the time of the beginnings of relativity, a hundred physicists stood up against Einstein, and an article was written "A hundred physicists against Einstein" proof that everything was not completely clear. So no, you are wrong Paul B.Andersen in saying that it is simple and that I am naive.
Einstein also replied "Why a hundred authors? If I was wrong, just one would have been enough."
We can still say the same thing today, and if you make a petition, you will find 100 authors to countersign the fact that I am wrong. But we still won't know more about the truth of things.
No, things are not simple. It is not easy to explain that "the effects of physics are symmetrical and reciprocal by permutation of observer".
This seems obvious, but as soon as the good doctor Hachel asks to apply the principle, no one can follow.
This therefore means that the expansion of the chronotropies is reciprocal by change of observer and simply as a function of relative speed. That is to say that moment after moment, the internal mechanism of Stella's watch will appear to beat more slowly for Terrence. On the way out, during the U-turn, and during the return. Always, always, always, Terrence will note that Stella's watch only goes 0.6 seconds while his watches beats 1 second. What is a paradoxical moment, if we do not understand this perfect reciprocity, is that for its part, second after second, on the way out, during the U-turn, and on the way back, Terrence's watch goes constantly beating slower for Stella. The reciprocity of the dilation of chronotropy is perfect.
So why is Stella 18 and Terrence 30?
This is true, but yet it seems absurd.
I explained it: because we confuse internal chronotropy (Lorentz factor, gamma factor) and measurement of time marked on watches.
It is not the same thing, and this is the first explanation of the paradox.
But there is a second, the spatial zoom effect, which is only a simple effect of elasticity of lengths and reciprocal distances.
Remember the term: reciprocal. Thus Stella's rocket seems three times longer on the return trip, but Terrence's telescope will also appear three times longer. The distance itself between his rocket and the earth will be three times longer: the highlight of the show and the point of reasoning in which intervenors like Python literally drown without understanding anything about the beauty and evidence of the theory.
So no, it's neither simple nor naive.
R.H.