3 ms·

I thought black holes typically have accretion disk.

• zaarn 8y ago
  Only when active and sucking in matter. If a black hole has been travelling without eating for long enough the accretion disk can disappear. If a black hole is large enough it won't form an accretion disk either as it swallows stars whole.
  • hvidgaard 8y ago
    That is actually scary. When you travel in interstellar space, you can only travel in directions where you can see light at all times.
    • leonroy 8y ago
      Which actually becomes a problem in the far future when stars have moved further away from each other in an ever expanding universe and their light output becomes increasingly dim to a space faring traveller...
      • hvidgaard 8y ago
        When I think about it, maybe it isn't a problem after all. I would think that you can measure gravity and see black holes before you hit them.
        • zaarn 8y ago
          Measuring gravity is hard. What you can do is measure gravity at both ends of your ship and if they differ by a lot you're currently being shredded apart by a blackhole.
          • hvidgaard 8y ago
            I'm sure that we'll have that figured out once we can manage interstellar travel.
  • Retric 8y ago
    You can still detect the bent light around it from other stars. They would be significantly more obvious than planets, and you would actually reflect a tiny fraction of radar as it gets bent around the thing.