Re: Langevin's paradox again

Le 04/07/2024 à 20:27, hitlong@yahoo.com (gharnagel) a écrit :

Richard Hachel wrote:

>
Langevin's paradox.
The Langevin paradox is a very serious criticism against the theory of
relativity.

 No, it's not.  It's only a paradox when part of the operation is
ignored.
That part has been explained in more than one way, but some don't seem
capable of understanding.
 

[Verbal bobbling deleted]
>
What was the grievance?
>
If the twin of the stars returns younger in the frame of reference of
the twin who remained on earth, then the twin who remained on earth,
if we apply the reciprocity of effects, and Doctor Richard Hachel says
that we must use this notion of reciprocity,

 Dr. Hachel is wrong, along with all those who conveniently forget about
the turn-around.  And "reciprocity" doesn't even enter Dr. H's solution.
 

very basis of logic, comes back older than the other. Which is both
logical and absurd.

 “No, no, you’re not thinking: you’re just being logical” – Niels Bohr
 “Logic is like the sword--those who appeal to it shall perish by it.”
-- Samuel Butler
 

No one has ever been able to answer the question correctly and
perfectly

 Incorrect assertion.
 

[Self-aggrandizing verbage deleted]
>
The great problem facing the world's physicists is a problem of
confusion.
They confuse two notions: the notion of relativity of measured times,
and the notion of reciprocal relativity of chronotropies.

 Incorrect assertion.
 

It's not the same thing.
>
Hence the impossibility for them all to explain things coherently.

 Not impossible.
 “There is no point in using the word 'impossible' to describe something
that has clearly happened.” – Douglas Adams
 

The relativity of the measured times will show that over a journey of 24
light years, carried out at v=0.8c, Terrence will age by 30 years.
It's very simple: x=v.t, i.e. t=x/v and 24[/]0.8=30
But when Stella returns, she will only be 18 years old[er].

 [Corrections made].
 

There is therefore an asymmetry, that is obvious, but it is on the
explanation of the asymmetry that everyone sinks into complete
ignorance.

 Not everyone, and there is more than one way to skin a cat.
 

Because we are confusing it with the notion of chronotropy, which is
ANOTHER THING, and which can be defined by the internal functioning of
watches. On this, yes, the effect is symmetrical, reciprocal; each
watch, and throughout the entire journey, (including if I place a small
half-turn phase on a semi-circle with a preserved tangential speed of
0.8c), beats faster than the other watch, and the equation is constant
and reciprocal over the entire path: T2=T1/sqrt(1-v²/c²).
>
This is true.
>
But this only qualifies chronotropy, that is to say the internal
mechanism of watches, it is not the whole of the relativistic effect.
>
This is not what we will ultimately measure.
>
I can't explain it more clearly.

 Then you have failed.  Whether the entire path a semicircle, or just the
end is a semicircle, particle physicists have known for nearly a century
that time dilation occurs on circular paths based only on the velocity
around the path.  So Dr. hachel is a few years too late.
 If the semicircle is at the end of a straightaway, then Stella will
endure
a humongous acceleration and return home a puddle of goo.  If, OTOH, her
trajectory is a giant circle of 24 Lyrs circumference, she will, indeed,
be 6 years younger than her twin, but if she wanted to reach a
destination
24 LYrs AWAY, she will only reach a distance of 7.6 Lyrs from home.
 Usually, the problem is proposed as reaching a destination along a
linear
path and then returning, not taking a grand tour.

Your criticisms have no point whatsoever. You say anything to save a sinking ship.
In any case, if you do not want Stella to be crushed by the acceleration of the U-turn, but the U-turn remains negligible, we can take a period of 25 years to make this U-turn, in correct conditions and make a journey of 30,000 years, instead of 30 years.
It won't change much. She will not be crushed, and she will return 18,000 years old.
I find it a shame that every time I explain something that is nothing more than a thought experiment, I am given stupid arguments (Stella is going to be crushed, the spinning relativistic disk is going to explode, etc.). .).
All of this sinks into ridicule with the sole aim of not thinking about the relativistic evidence that I explain, and which is much more logical than what we find in the textbooks.
R.H.