Re: Understanding the theory of special relativity

W dniu 18.01.2025 o 20:28, Paul.B.Andersen pisze:

Den 18.01.2025 10:04, skrev Richard Hachel:

Le 17/01/2025 à 13:30, "Paul.B.Andersen" a écrit :

>
Stella is in a rocket and is co-located with Terrence when
she starts her rocket engine and accelerates at 1 c/year
away from Terrence for 2.25 year on her clock.
Then she turns her rocket around and accelerates at 1 c/year
towards Terrence for 4.5 years.
Then she turns her rocket around and accelerates (brakes) at 1 c/year
away from Terrence for 2.25 years.
>
When Stella is back at Terrence both stop their watches.
They are now co-located and stationary to each other.
Their clocks are side by side and can easily be compared.
Terrence clock shows 23.7 years.
Stella's watch shows 9 years.

>
In the problem you pose:
A rocket leaves the earth and accelerates (a=1ly/year).
This during a proper time Tr (or tau) = 2.25 years.
Which gives a total of Tr=9 years.

 It is the very same as this scenario:
https://paulba.no/pdf/TwinsByMetric.pdf
See: 2.2 B travels with constant speed and instant acceleration
And: 2.4 Concrete example
 This is what SR predicts:
 When Terrence (Twin A) is back, his watch show 23.664 y ≈ 23.7 y
When Stella is back (Twin B), her watch show 9.912y ≈ 9 y
(bad round off, but doesn't really matter)

This is what SR predicts, and anyone can check
GPS - it has nothing in commom with real clocks.