• GreyEyedGhost@lemmy.ca
    link
    fedilink
    arrow-up
    0
    ·
    6 months ago

    So all you need is a perfect charging system. We don’t have those, and physics doesn’t allow for them. This would be no different than the laser example I gave, and this only makes sense after you have a second Dyson swarm.

    • FooBarrington@lemmy.world
      link
      fedilink
      arrow-up
      0
      ·
      6 months ago

      Why perfect? As long as the efficiency is high enough, you wouldn’t see the sphere itself as very bright, it would be quite dim. Do we know any hard, physical limitations for this, like we do for speed?

      • Blóðbók@slrpnk.net
        link
        fedilink
        arrow-up
        0
        ·
        6 months ago

        A partial answer to your question is that there’s a minimum amount of heat necessarily radiated when doing computation, given by the Landauer principle.

        Furthermore, I also do not think that we will detect dyson spheres, because if a civilisation wishes to hide, they won’t radiate heat uncontrollably by extracting all possible energy, but rather send that energy elsewhere, for example by dumping it into a black hole. But I could be wrong and such a civilisation might care more about energy than remaining undiscovered.

        • FooBarrington@lemmy.world
          link
          fedilink
          arrow-up
          0
          ·
          6 months ago

          A partial answer to your question is that there’s a minimum amount of heat necessarily radiated when doing computation, given by the Landauer principle.

          It’s not a given that Landauer’s principle is an absolute threshold - the Wikipedia article describes challenges, and there are attempts like Reversible Computing which can potentially work around it.

          Furthermore, I also do not think that we will detect dyson spheres, because if a civilisation wishes to hide, they won’t radiate heat uncontrollably by extracting all possible energy, but rather send that energy elsewhere, for example by dumping it into a black hole. But I could be wrong and such a civilisation might care more about energy than remaining undiscovered.

          Fully agree that such an advanced civilization will most likely want to hide, and stop any infrared radiation to the largest part.

          • Blóðbók@slrpnk.net
            link
            fedilink
            arrow-up
            0
            ·
            6 months ago

            Reversible computing can not work around it because one simply can not extract information without irreversibly affecting the system. This is a fundamental constraint due to how, in quantum mechanics, once an observer entangles themselves with a system they can never unentangle themselves. I believe that from that single fact one can derive the impossibility of reversible existence.

            • FooBarrington@lemmy.world
              link
              fedilink
              arrow-up
              0
              arrow-down
              1
              ·
              6 months ago

              Better go tell the theoretical computer scientists who waste their time writing papers on the topic! Could save them a lot of trouble if they had just asked you.