I’m asking this because there is a scifi book I’m reading, and in the book there’s a scene where someone is communicating with a person in a spacecraft moving at lightspeed. I know their ability to communicate would probably not be possible, but let’s just put that aside for a second. Hypothetically, if you could communicate with someone moving lightspeed, would the time dilation make it so that they would appear to be moving and speaking very slowly relative to you?

  • WoodScientist@lemmy.worldEnglish
    6·
    22 天前

    Yes. Distant galaxies that are moving away from us at relativistic speeds exhibit measurable time dilation in their inner workings.

    How would you even measure time dilation in a distant galaxy? Consider standard candles like 1a supernova, which explode with near uniform power. These supernova can be observed from intergalactic distances. Gather data and record the times for various supernova explosions. You’ll find that the same types of explosions take longer in more distant galacies, and that the extra time is exactly what relativity predicts.

    • a_gee_dizzle@lemmy.cadeleted by creatorOPEnglish
      1·
      22 天前

      You’ll find that the same types of explosions take longer in more distant galacies, and that the extra time is exactly what relativity predicts.

      That’s incredibly cool. From a point of view of a being near that supernova, would we be moving a lot faster?

      • tburkhol@lemmy.worldEnglish
        2·
        22 天前

        From the point of view being near the distant supernova, we are moving away from them at relativistic speed, so as much slower as they appear to us, we should appear that much slower to them.

          • frongt@lemmy.zipEnglish
            21·
            22 天前

            It’s just two objects moving apart. If I drive my car away from yours, it looks exactly the same as if you had driven away from me (once you delete all the frames of reference like the ground, because there is no ground in space). The other person gets smaller at the same rate.

            Have you ever been in a car or train where you couldn’t see the ground, only another car or train next to you? And you see the other vehicle moving, but you can’t tell if it’s actually them or you moving? Same thing. It’s all relative.

            • a_gee_dizzle@lemmy.cadeleted by creatorOPEnglish
              1·
              22 天前

              I’m just confused as to how we could both experience time dilation at the same time. Isn’t our time only dilated in relation to each other? So if both our times were dilated there would be no relative difference and it would look like our clocks were in sync, no?