Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The Twins Paradox illusion

  1. Jan 11, 2015 #1
    I've read different reasons for the reciprocal illusion experienced by the twins (the slow-motion effect). I've not been able to understand the reason that the traveling twin would see the earthbound twin moving in slo-mo. Can anyone offer a simple explanation -- or is there actually no agreement on this within the physics community?

    Thank you very much!
  2. jcsd
  3. Jan 11, 2015 #2


    User Avatar
    Science Advisor
    Gold Member

    There is certainly agreement that the traveling twin would also see the Earth bound twin's time being dilated (moving in slow-mo as you say). This is due to the fact that in special relativity neither frame, the Earth frame, nor the traveling frame, is special (until the traveling twin has to slow down and come back). Thus, there is no way to assign the "traveling twin" as being the one that is actually traveling, rather than the Earth twin as the one that is traveling, so whatever the "traveling twin" sees, the Earth twin must see the mirror image of that.
  4. Jan 11, 2015 #3


    User Avatar

    Staff: Mentor

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook