Edit: Due to popular demand FatTony Search servers are down for the time being. but has gone open source just in time (Yes that’s how it works 😡) . You may now get responses from other users. Servers will be back up some time later.

  • ripcord@lemmy.world
    link
    fedilink
    arrow-up
    2
    ·
    6 months ago

    Somewhat related: let’s say you’re moving at 80% the speed of light away from earth. Then you turn on a flashlight and point it away from earth.

    • How fast is the light emitted moving relative to you?
    • How fast is it moving relative to earth?
      • ripcord@lemmy.world
        link
        fedilink
        arrow-up
        2
        ·
        6 months ago

        OK, so after 1 hour:

        • How much further away are you from earth?
        • How much further away from you is the light?
        • How much further away from earth is the light?
        • Jojo, Lady of the West@lemmy.blahaj.zone
          link
          fedilink
          arrow-up
          2
          ·
          6 months ago

          It depends. The light is definitely moving at c, no matter who checks and from everyone’s perspective, but as a consequence of that the answers to those other questions change depending on how you measure. The coordinate system (technically the “reference frame”) you choose changes the answer. Even more, time isn’t the same for each frame, so you even have to specify for whom it has been 1 hour.