• Canis_76@feddit.nl
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    1 year ago

    I remember when I used to believe that nothing escaped a black hole past the event horizon. I remember when I used to think a black hole was an actual hole. I sure hope Santa isn’t late this year. There are some things still with believing in.

    • rbesfe@lemmy.ca
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      1 year ago

      You’re still right about that first part. It’s a poorly written headline, all of the matter being ejected hasn’t passed the event horizon

      • Natanael@slrpnk.net
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        1 year ago

        There’s the hard event horizon and then there’s multiple radii past it with different effects on orbits (such as the photon orbit radius, stable circular orbit radius, etc) and if you’re very close you’re also dealing with “weaker” horizons like a radius where most light gets redshifted past visibility even if mass can still escape if it’s fast enough.

        https://profoundphysics.com/black-hole-orbits/

    • FooBarrington@lemmy.world
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      1 year ago

      I remember when I used to believe that nothing escaped a black hole past the event horizon.

      I mean, nothing does, so why did you change your beliefs?

  • subignition@kbin.social
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    1 year ago

    I wonder if it’s going to turn out to be analogous to throwing a ball into a cylinder, where some of the matter enters at a precise trajectory that basically causes it to bounce back out? Assuming nothing is actually exiting from the event horizon, maybe there’s some sort of stratification of the elements within the accretion disk? Or maybe there are oddly hyper-stable orbits, why they’re lasting years, and it’s analogous to the way a coin can take a very long time to settle when falling on its side.

    It seems less likely that there’s a mechanism by which something can actually cross the event horizon from inside, but who knows, new physics might be out there to have something to say about it.

    Edit: I’d be REALLY curious to know whether the time interval of the delay is correlated with the half-life of any radioactive elements that would be present in the devoured star.

    • SocialMediaRefugee@lemmy.world
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      1 year ago

      The consumed star is no longer a gravitationally bound object, it is torn apart by tidal forces. She says the disk is supposedly unstable and half should disperse within hours and the rest within a month or so, so this delay is odd.

      There is no way to return across the event horizon. You’d have to go faster than light and all timelines lead to the singularity inside the EH.

      There is no such massive reservoir of unstable isotopes in stars and even if there was it wouldn’t all decay in a single event.

    • WetBeardHairs@lemmy.ml
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      1 year ago

      My guess is the event horizon has always been viewed as this perfectly spherical (or oblate spherical) construct - I bet it is much more messy than that. I bet the event horizon moves around and the movement allows for materials to be ejected.

  • webghost0101@sopuli.xyz
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    1 year ago

    I am probably looking to deep into this but a recent kurtzgesagt claimed that once you get to the event horizon time and space switch into eachother. Your no getting sucked into the center. But your falling into the future.

    Sm coming back out years later doesn’t sound like a contradiction to that,

    • wahming@monyet.cc
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      1 year ago

      According to the discoverer, this has nothing to do with the event horizon.

          • webghost0101@sopuli.xyz
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            1 year ago

            The first sentence of the body text in the article:

            “Up to half of the black holes that devour stars “burp up” their stellar remains years later.”

            I recognize that its not an entire sun being sucked in at once and that the black holes presence alone destroys the sun but the parts that are left. Radiation and what not should still be attracted to the black hole and assumingly orbit around its gravity before gething devoured.

            It cant burp something out that was never inside. Or maybe it does but those implications are even more bizar. If it was just “burping out” the surrounding star stuff it wouldn’t be called a burp but “pushed it away again.

            How else am i to interpret this?

            • wahming@monyet.cc
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              1 year ago

              Maybe don’t read too much into the word choice of a non-technical article, and trust the actual astronomer discoverer talking about it?

              • webghost0101@sopuli.xyz
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                1 year ago

                The top comment stating who discovered it was there yet when i made my initial comment where i was upfront that i may be looking to deep with my limited knowledge.

                While i recognize that the discussion here has evolved with more nuance and smarter opinions you cant blame me for sticking with the original conversation which is the posted article. After all i am just respond to the replies i get i am not going to re-read the entire thread every time.

                I also recognize that the first person to reply did say “According to the discoverer, this has nothing to do with the event horizon.”

                But there was no source and i just read it as the “horizon has nothing to do with the burp” that doesn’t mean the twisted physics inside it do not.

        • jpeps@lemmy.world
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          1 year ago

          You’re correct, but so is the person above. These stars are not (entirely) crossing the event horizon. Lots of material is left orbiting around the edge forming a disc. It’s this disc, the formation of it, and the ejection of material from it, that’s relevant here.

    • exponential_wizard@lemm.ee
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      1 year ago

      There’s almost nothing more contradictory to that. While within a black hole, time becomes space-like, with your future being the inevitable center. The only possible way to escape would be to go back in time.

      Well that’s assuming einsteinian physics, black holes are one of the few cases our physics stops making much sense.

      • webghost0101@sopuli.xyz
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        1 year ago

        I guess the future being at the center is what makes it confusing to me.

        In my head disappearing while being pulled towards their future and then someMaterial being burped out in the future sound like some parts arrived at a destination.

        I would assume the material being burped out has been inside while l pulled towards the future till it no longer was.