• leftzero@lemmy.dbzer0.com
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    6 days ago

    graph function singularities exist as physical features in our world

    Do they, though…?

    As I (mis?)understand it, as a massive star begins to collapse, getting denser and denser, the gravitational gradient gets steeper and steeper… and time (from the perspective of an outside observer) gets slower and slower… to the point that, from our point of view, the full collapse (or maybe even any collapse below the Schwarzschild radius?) hasn’t happened yet, and won’t happen until the extremely distant future, beyond the end of the universe…

    So, in that sense, from the point of view of “our world”, no singularities (except possibly the big bang) would ever exist (yet), all of them being censored not only by event horizons, but by being shoved into the perpetually far future, beyond time itself…

    And, speaking about event horizons, isn’t the whole “light isn’t fast enough to escape” concept a misinterpretation of sorts…? As I (again mis?)understand it, it’s not a matter of speed, but of geometry… The way space-time is twisted in such a gravitational gradient, once you get past the event horizon there are no longer any directions pointing towards the outside.

    Which is another from of cosmic censorship (or a different effect or interpretation of the above), preventing anything inside the event horizon from causally interacting with the outside universe…

    So, if these singularities are hidden beyond sight, causally, visually, and geometrically isolated from the rest of the universe, and perpetually shoved into the far future… can they really be said to exist in our world…?

    (Of course there’s always the big bang, but we can’t really observe that one, only its effects, and it’s not necessarily exactly what the original post was talking about anyway…)

  • MissJinx@lemmy.world
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    6 days ago

    thinking about the universe is already traumatizing

    Where does it end? How are we floating? What if we fall? Where does it come from?

    I don’t think about that a lot so it doesn’t give me anxiety

  • MudMan@fedia.io
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    8 days ago

    I’m not an astrophysicist, but that ends up being the weird perception thing about them, right? Mostly they’re like a star of the same mass, and then a few will get really big and be at the center of a galaxy, but the perception is that of a natural disaster.

    Big ball of plasma in the center of the solar system that will definitely eventually explode and wipe out anything left alive on any surrounding planet? NBD. An object of the same mass but it’s smaller so it doesn’t shine? People picture it as being more immediately violent for some reason because the “light can’t escape” thing sounds so wild.

    • daniskarma@lemmy.dbzer0.com
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      6 days ago

      They are like stars in the sense of orbital mechanics.

      But a star can be completely understood by the laws of physics we know. While a black hole breaks our understanding and we have no idea what’s going on in there.

      It’s the fear of the unknown.

    • brucethemoose@lemmy.world
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      6 days ago

      Pop sci-fi seems to be fond of intermediate-mass black holes (EG Interstellar, Star Trek StrangeNew Worlds), and for something kinda the size of a star, they are “scary.”

      In other instances (like in TV Foundation), a close orbit to the accretion disk is a source of suspense.

      And then there’s the “stealth” aspect. Stellar-mass ones and below are very small and (potentially) quiet for something with the mass of a star, eg easy to stumble upon.

      And in some very advanced universes (eg the online Orion’s Arm), even with “hard” sci fi, swimming through a star’s nuclear plasma is totally doable. But a black hole is an impossible boundry of physics, and an particularly extreme object useful for astroengineering.

    • Fermion@feddit.nl
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      7 days ago

      Yeah, black holes in media where they are depicted as a giant space vacuum cleaner is a big pet peave of mine. Unless you get really close, nothing is remarkable about the orbital mechanics of a black hole. The equivalent mass star would have burned you up at a much further distance than the gravity starts to become noticeably wonky.

      It’s a shame that writers focus so much on the gravity and neglect accretion disks and astrophysical jets which do extend large distances and are visually stunning as well.

    • emergencyfood@sh.itjust.works
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      7 days ago

      Big ball of plasma in the center of the solar system that will definitely eventually explode and wipe out anything left alive on any surrounding planet?

      The sun isn’t heavy enough to go supernova. (Unless it has a companion, but there’s no evidence of one so far.)

      • MudMan@fedia.io
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        7 days ago

        It will still expand and shed enough stuff to effectively blanch whatever part of the solar system it doesn’t actually engulf, though.

        It doesn’t even have to go supernova to kill everything, which is kind of the point.

  • LibertyLizard@slrpnk.net
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    8 days ago

    My understanding is that the singularity is not proven to exist and many physicists believe it is an artifact of our incorrect understanding of the physics involved.

  • radix@lemmy.world
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    8 days ago

    Teachers: You can’t divide by zero.
    Nature: Hey guys, check this shit out.

    • pressanykeynow@lemmy.world
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      7 days ago

      There are math models where dividing by zero makes sense. It’s just that those models don’t suit our world for now.