Black hole singularity is a surface not a point

(arxiv.org)

34 points | by raattgift 1 hour ago

10 comments

  • Groxx 0 minutes ago
    [delayed]
  • Certhas 51 minutes ago
    As is nicely visualised by it's Penrose Diagram, e.g.

    https://jila.colorado.edu/~ajsh/insidebh/penrose_schw.gif

  • sigmoid10 54 minutes ago
    Should be pointed out that this is a critique of common popsci journalism tropes and not a fancy new research result. Anyone who has taken a graduate level class in General Relativity would have been able to tell you the same.
    • kwoff 34 minutes ago
      Or read Susskind's "The Theoretical Minimum: General Relativity". For a non-spinning blackhole at least, not only is the singularity not a point, it is a surface in time, not space (as the book explains, the space and time coordinates switch places as you cross the event horizon).
    • huflungdung 51 minutes ago
      [dead]
  • dekdrop 27 minutes ago
    How does one descr blackhole to a non-physicist without losing much accuracy? I just it of a very-dense-object.
    • crooked-v 24 minutes ago
      The problem there is that not even the physicists completely agree on the details, because we know black holes definitely exist, but every explanation breaks one rule or another that should apply from different disciplines. It's part of why they get so much ongoing attention.
      • lazide 21 minutes ago
        Black holes are essentially where our knowledge of spacetime breaks, and we can’t even see into it. It’s hard to really concretely know much about it directly.
    • icepush 26 minutes ago
      A one-way door in space.
  • Eridanus2 50 minutes ago
    Contains 08 rendered frames of a free falling observer's view while crossing the event horizon. This is not reddit, but plz someone animate it :}
  • ck2 46 minutes ago
    what's really going to blow your mind is

    while you probably assumed or knew spinning black holes move space around them

    spinning black holes also move TIME around them

    * https://www.science.org/doi/10.1126/sciadv.ady9068

    so in theory a spinning black hole that's been around for billions of years has a time drag around it in a path that is billions of years old

    (no we can't navigate it because yes that would be time travel to the past and violates causality)

    black holes are just so weird with every new detail even more weird

    oddly more interesting to me to try to grasp neutron stars (densest objects before black holes and are still visible, our entire solar system in a neutron star would be only 10km 6.2miles across)

    • srean 15 minutes ago
      Consider the magnetar.

      https://en.wikipedia.org/wiki/Magnetar

      "A magnetar's 10^10 tesla field, by contrast, has an energy density of 4.0×1025 J/m3, with an E/c2 mass density more than 10,000 times that of lead."

  • 542458 34 minutes ago
    [dead]
  • helf 44 minutes ago
    [dead]
  • jamesforestwest 43 minutes ago
    Interesting work. The idea that the singularity is a surface rather than a point was unexpected to me even though it seems to follow logically from the theory of relativity. I wonder how this reconciles with quantum gravity. If the singularity is truly a two-dimensional surface, perhaps it's related to Hawking radiation and the thermodynamics of black holes?