• OrganicMustard@lemmy.world
    link
    fedilink
    English
    arrow-up
    2
    ·
    10 hours ago

    Black holes don’t need to be dense. A black hole the size of the orbit of Jupiter would be less dense than water.

    Black holes radiate energy like a black body with a temperature that increases fast the smaller they are. Small black holes radiate all their energy really quickly.

    • Creat@discuss.tchncs.de
      link
      fedilink
      English
      arrow-up
      3
      ·
      10 hours ago

      That’s not what I was saying. What I was saying is that if they are light in mass (kilos, tons) they need to be dense. Didn’t wanna write a book just for that one point, and it already got long-ish anyway.

    • four@lemmy.zip
      link
      fedilink
      English
      arrow-up
      2
      ·
      9 hours ago

      Don’t you mean the event horizon of the black hole? The actual matter of a black hole is in an infinitely small point, right?

      • OrganicMustard@lemmy.world
        link
        fedilink
        English
        arrow-up
        3
        ·
        5 hours ago

        The horizon is what defines the black hole. From the outside the mass distribution is not defined, as there isn’t any experiment you can do that tells you about the internal structure. If you let a mass fall into a black hole you won’t see it cross the horizon, just get asymptotically closer to it.

      • chunes@lemmy.world
        link
        fedilink
        English
        arrow-up
        1
        ·
        9 hours ago

        Very very small but not infinitely so. That would violate the Heisenberg uncertainty principle of quantum mechanics.