12 comments

  • sgt101 2 hours ago
    Could this kind of trigger effect the standard candle application of Type 1a's? For example, if a black hole triggers a type 1a and that perturbs the type 1a light curve in some way (possibly because less mass could be consumed in the explosion than you would get if one was triggered by mass accretion) and the rate of triggering of this kind changed over time as the universe aged and somehow the population of primordial black holes changed, or the distributions of white dwarf candidates and pbhs changed...
    • antognini 1 hour ago
      They did some modeling in a previous paper of how this would impact Ia supernovae and it depends on whether the supernova is driven by Kelvin-Helmholtz instabilities or not. In the case that it is, this would only trigger Ia supernovae for white dwarfs which are already very close to the Chandrasekhar mass. In this case the standard candles would be pretty much the same.

      In the case that KH instabilities are weaker they claim that you can get supernovae at masses farther from the Chandrasekhar limit. This could plausibly have more of an impact on Ias as standard candles. (Though perhaps less than you might think becauseit would also likely have an effect on the shape of the light curve, and Ias are normalized based on their light curve shape.)

      All that said, even if this process does occur, I doubt the rates would be high enough for it to be a substantial fraction of observed Ias.

  • cousinbryce 2 hours ago
    Anyone have guesses about how a transiting primordial black hole would effect a Sun like star? Paper is about tidal forces inducing supernova in white dwarfs. For that matter how might it effect sea tides?
    • jandrewrogers 49 minutes ago
      Most likely minimal? The mass is low.

      I am, however, reminded that the orbit of the asteroid Juno (~250km diameter) permanently changed in 1839 without an obvious cause.

    • pavel_lishin 2 hours ago
      For the latter, you mught enjoy Greg Egan's "Perihelion Summer".
    • temp0826 28 minutes ago
      Picturing the crust of the earth being pulled off like an orange peel. But maybe seen too much scifi so it's probably a lot more boring :/
      • pavel_lishin 1 minute ago
        I think at the energy scales we're talking about, everything involved would basically act like a fluid.
    • antognini 1 hour ago
      We have constraints that primordial black holes must be less than the size of a large asteroid. They would be gravitationally insignificant to the Earth unless they actually passed through it.

      I also don't think it would really be detectable in the Sun. Perhaps there would be some transient astroseismology signature.

    • ButlerianJihad 2 hours ago
      fnord
  • Schlagbohrer 2 hours ago
    3-Body-Problem once again vindicated as the scariest possible explanation for the Fermi Paradox
    • 9dev 2 hours ago
      Many physicists have pointed out several flaws in the dark forest theory, which makes for a great read but doesn’t really carry over to the real universe 1:1.
      • Schlagbohrer 1 hour ago
        Can you point me to more info on that or just tell me? I am curious about reasons to be more optimistic than that book lays out. I would much prefer the Carl Sagan view of the Cosmos as one where it simply makes no physical nor cultural sense at all to be aggressive toward other stellar civilizations.
      • graemep 1 hour ago
        What flaws? Do they apply to variants such as Greg Bear's and related ideas such as berserkers?
      • bpodgursky 1 hour ago
        Why would physicists have anything useful to say about this theory?
        • 59percentmore 1 hour ago
          Because environment makes culture and physics are the environment at relativistic speeds and cosmic distances.
    • criddell 2 hours ago
      Did you intend to say dark forest hypothesis?
      • istjohn 1 hour ago
        According to physicist Sean Carroll, "hypothesis" and "theory" are interchangeable as the words are used by practicing scientists.
        • rigrassm 34 minutes ago
          I love Sean Carroll (Something Deeply Hidden and From Eternity to Here are the root of my fascination with physics and endless pondering of the nature of time) but I have to disagree with his take on this.

          Hypothesis - a proposed explanation for something (such as a phenomenon of unknown cause) that is tentatively assumed in order to test whether it agrees with facts that are known or can be determined.

          Theory - a scientifically acceptable or plausible general principle or body of principles based on data and offered to explain phenomena

          Just because those outside of scientific fields use them interchangeably doesn't change the fact that they carry different meanings in scientific contexts.

          • criddell 26 minutes ago
            Isn't Planck's hypothesis really a theory? Isn't string theory really a hypothesis?
      • Schlagbohrer 1 hour ago
        Yes!
    • etangent 57 minutes ago
      suspecting that star explosions are caused by nefarious super-intelligences is just Greek mythology with more steps.
    • andrewflnr 1 hour ago
      In what way? This is discussing, as far as anyone knows, an entirely natural phenomenon.
    • echelon 1 hour ago
      I think a fragile world hypothesis is more interesting and scary.

      Instead of a superintelligence killing any emerging intelligence, superintelligence is so smart that it can perturb spacetime in ways that easily kill itself.

      Kind of like the idea that LLMs will give anyone with a garage the ability to create killer viruses (wild claim), a superintelligence might trivially create black holes that engulf it. If the intelligence is distributed across many agents (or nations), someone will try something stupid that kills the entire population.

      It'd be even scarier if they could accidentally collapse the supposed vacuum state. Universal annihilation at the speed of light just because you got too smart.

      Fragile world / fragile universe meets "too smart for your own good".

      • andrewflnr 1 hour ago
        Leaving aside the fact that there's no evidence superintelligence is even possible, no amount of intelligence alone will let you "trivially" create black holes. Creating black holes requires a ludicrous amount of energy. Planet-scale energy, maybe solar-scale energy. Energy is conserved. You can't just think really hard and have it. At minimum you have to already have the energy and materials to build a machine that will let you (mostly build another machine that lets you) harness that much energy.

        It's at least not something you'll do by accident.

        • ButlerianJihad 7 minutes ago
          Origami Black Hole https://m.xkcd.com/3033/

          "It Really Brings the Room Together" https://m.xkcd.com/1680/

          M87 Size Comparison https://m.xkcd.com/2135/

          Black Hole Moon https://what-if.xkcd.com/129/

        • echelon 1 hour ago
          You don't know any of that.

          We are primitive apes. We are all uniformly dumb.

          • andrewflnr 59 minutes ago
            It's inherent to the math that defines the entire concept of a black hole, or "spacetime" in general. So to the extent we can contemplate the question at all, we can be pretty confident that creating black holes is Very Hard.

            There's a lot we don't know, but the fact that the universe is consistent means it has to be consistent with what we do know already. Don't be so openminded your brain falls out.

            • echelon 41 minutes ago
              > the fact that the universe is consistent

              We don't know this either.

              We are very limited in detection. Our energies are small.

              How "standard" are standard candles and other references? Are the facts that stand as the basis for our theories even correct?

              We are too primitive to be dealing in absolutes.

              • andrewflnr 12 minutes ago
                > > the fact that the universe is consistent

                > We don't know this either.

                See this is what I'm talking about as far as being too open-minded. Consider what it would mean for the universe to be inconsistent, particularly in relation to the astronomical observations that are the basis of this conversation.

      • alansaber 1 hour ago
        Sounds logical to me. It's already remarkable that we haven't done this with fission weapons. It's not unreasonable to assume that within a century we'll have antimatter weapons. Destructive potential only goes up.
        • SoftTalker 4 minutes ago
          We could not come close to destroying the world with fission weapons. We might make things very hard for humanity, but the world and life would continue, perhaps even benefit.
        • WarmWash 1 hour ago
          Every year the IQ needed to destroy the world drops by 1 point.
  • ck2 20 minutes ago
    If I remember correctly, Stephen Hawking had to do some serious math in the 1970s to convince himself a tiny black hole was not hiding in our Sun

    I think there's a PBS Space Time on it (of course)

    adding: yup! love that show

    * https://www.youtube.com/watch?v=Q6kJaMf3Lgo

  • thisisauserid 2 hours ago
    The "Great Filter" answer to the Fermi Paradox.
    • stronglikedan 2 hours ago
      It seems like it would be the most efficient implementation of the Great Filter, since it would just look like a natural occurrence to any observers.
  • choboswaggings 1 hour ago
    Kind of chilling to think about these tiny black holes. If they have enough gravitational pull to destabilize a white dwarf, I don't want to know what they'd do to our solar system.
    • ttul 1 hour ago
      These supernova-generating black holes are atomic scale (Schwartzchild radius of 15pm to 15nm), yet they carry the momentum of a large asteroid. If one of these hit the earth, they would cause a life-ending apocalypse like the event that ended the dinosaurs. The fact that this has not happened yet is encouraging.
      • shagie 5 minutes ago
        Can one detect passage of small black hole through the Earth? - https://arxiv.org/abs/0710.3438v1

        A physics stack exchange answer about it: https://physics.stackexchange.com/a/55184

        The most relevant part:

        > The total energy created by a PBH roughly equals the energy produced by the detonation of one tonne of TNT, but this energy is the total energy it deposits along its path through the Earths diameter, not the energy it produces on impact. So don’t expect a magnificent explosion, we’d be lucky to see a spark as it hits the ground.

      • YetAnotherNick 49 minutes ago
        The drag is insufficient to stop it and it would go right through the earth without stopping. It would cause earthquake of 4 magnitude, which is barely detectable.

        [1]: https://arxiv.org/pdf/1203.3806

    • ungovernableCat 1 hour ago
      PBH (if they exist) are microscopic in size. If they're real and qualify as a potential dark matter candidate they have passed our solar system many times with the only thing happening being undetectable gravitational tugs.
  • boesboes 2 hours ago
    Wouldn't Type Ia supernovas caused by blackholes have a different brightness? That could mean the entire cosmic ladder needs to be revised, maybe this could resolve the crisis in cosmology..
  • brabel 1 hour ago
    Fuck this site with its multiple ads opening up and auto playing videos.
  • aklemm 1 hour ago
    And yet no one does a thing about it.
    • PowerElectronix 1 hour ago
      Be the change you want to see in the world. Go out there and start swatting away nanoscopic black holes.
    • CookieCrisp 1 hour ago
      What would you like done?
  • empath75 2 hours ago
    This is one of those headlines where I simultaneously think "cool" and now have a new source of low-grade background anxiety about. It can have a seat next to false vacuum collapse.
    • Zigurd 2 hours ago
      Take comfort in the fact that compared to the size of the universe, the speed of light is like molasses in January. Cosmological eschatology is a very slow game, and the odds of you being alive and in the right place to be a spectator are literally astronomically small.
    • OneDeuxTriSeiGo 2 hours ago
      In that case you may enjoy “The Blue Afternoon that Lasted Forever” by Daniel Wilson.

      https://web.archive.org/web/20260310115201/https://www.willi...

    • alansaber 1 hour ago
      Concern for celestial events is a bit like one of your gut bacterium being concerned with your work schedule
    • trollbridge 2 hours ago
      The good news about black holes is that even if one transited the solar system, it would be extremely unlikely to come anywhere near earth.
      • ben_w 2 hours ago
        The bad news is that if a black hole is not primordial, the minimum mass is high enough (2-4 M_sol) that it doesn't so much "pass through our system" as "we pass through its".

        I'm not 100% confident, but rough approximation suggests that a close approach of even 5 AU even at typical interstellar velocities might have an unplesant climate impact by increasing the eccentricity of our orbit.

        • trollbridge 1 hour ago
          Déstabilise orbits - definitely, but the same would be true of a star or other celestial body.

          But our risk of getting sucked into a black hole is really tiny. (Although personally if I had a chance to enter a black hope, I would. I’m just naturally curious.)

        • 14u2c 1 hour ago
          5AU seems incredibly close. That's inside the orbit of jupiter. How would it not destabilize the entire system?
        • mynegation 2 hours ago
          Did you mean 5 AU or 5 ly? 5 AU at 2-4 M sol intuitively seems like a complete and utter havoc.
          • ben_w 1 hour ago
            We know what something with about 2 solar masses looks like at about 5 light years, because there is such a thing a bit closer: the Alpha Centauri system.

            So (and again, this is very rough approximation) I mean AU: consider the high speed of interstellar encounters so it won't be there for long, and that it takes the full pull of Sol 6 months to turn us around 180°.

            Also, yes, in general this would cause a lot of the Oort cloud to destabilise and a long period of bombardment of all the planets.

          • kbelder 1 hour ago
            At 5 AU, gravitational force would be 1/25 or 4% the strength of the sun at 1 AU. If the black hole was four solar masses, it would exert a pull about 16% as strong as the sun. Probably not enough to rip us out of orbit, but enough to seriously perturb it. I think it's at least an end-of-civilization event.

            5 AU is the perfect distance to really wreck Jupiter, though.

            • bell-cot 1 hour ago
              Not an astrophysicist, but I'm thinking 5 AU could quickly fry the Earth - because it takes very little in the way of solar comets, asteroids, and dust to build a temporary accretion disk around such a black hole. That disk might have a temperature of >1M degrees. Plus the dynamo effects of the disk's interactions with the solar magnetic field? Yeah. 5 ly sounds much safer.
              • ben_w 51 minutes ago
                > Yeah. 5 ly sounds much safer.

                Well yeah.

                I clearly could've phrased this better though: I was aiming for "here is an example distance which *is* bad", not as it appears to have been understood "here is the distance where it is *not* bad".

                • bell-cot 27 minutes ago
                  I mostly noticed your "might have an unplesant climate impact by increasing the eccentricity of our orbit", and thought that'd be the least of Earth's worries.

                  Black hole gravity is ruthless about turning nearby mass into deadly fireworks.

      • 98codes 1 hour ago
        > extremely unlikely

        But never zero.

  • BedVibe_Studios 1 hour ago
    [flagged]
  • raiyanr 1 hour ago
    when will sun be exploaded?
    • Y-bar 1 hour ago
      More than eight minutes ago. At least.