From: fortunati.luigi@gmail.com   
      
   Il giorno marted=C3=AC 18 luglio 2023 alle 09:28:25 UTC+2 Stefan Ram ha   
   scritto:   
   > There is an additional time of aging on Earth that you have not   
   > taken into account.   
      
   Il giorno marted=C3=AC 18 luglio 2023 alle 09:28:25 UTC+2 Richard Livingston   
   ha scritto:   
   > You are failing to take into account the acceleration when the traveling   
   brother turns around. There is a sudden shift in "now" on earth for the   
   traveling brother during that acceleration.   
      
   The sudden change of time on Earth is not painless.   
      
   If in one minute of the spaceship the time on Earth changes by 24 hours,   
   it means that in that minute of the spaceship the Earth becomes a crazed   
   top that makes a complete revolution on itself in one minute.   
      
   And do you want to know how much Earth time jumps forward when the   
   spaceship reverses?   
      
   I'll do the calculations.   
      
   The traveling twin ages 48 hours outward and 48 hours back, so he returns   
   to Earth aged 96 hours (4 days) and should find the Earth twin aged twice   
   as much (8 days, 192 hours).   
      
   But since during the journey the terrestrial twin ages by only 48 hours   
   (24 hours during the outward journey and 24 during the return journey),   
   all the remaining aging (6 days and 6 almost instantaneous rotations!)   
   should take place during the U-turn.   
      
   Is this what you two think is happening?   
      
   Is it during the U-turn that (in the reference of the spaceship) the Earth   
   rotates madly (6 almost instantaneous rotations)?   
      
   [[Mod. note -- No, during the U-turn the spaceship observer *observes*   
   the Earth to rotate madly.  But at the same time an observer stationary   
   with respect to the Earth *observes* the Earth rotating at its normal   
   angular velocity.   
      
   This is sort of like taking a video of something, then having two   
   observers play back the video at differing rates -- one observer   
   playing back the video at a very high frame/second rate observes the   
   action happening very fast, while the other observer playing back the   
   video at a normal frame/second rate observes the action happening   
   normally.   
   -- jt]]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)