[HN Gopher] Tiny black holes may be exploding stars across the M...
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Tiny black holes may be exploding stars across the Milky Way
https://iopscience.iop.org/article/10.3847/1538-4357/ae6db7
Author : jandrewrogers
Score : 84 points
Date : 2026-08-05 15:57 UTC (1 days ago)
(HTM) web link (www.sciencedaily.com)
(TXT) w3m dump (www.sciencedaily.com)
| empath75 wrote:
| 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.
| trollbridge wrote:
| 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 wrote:
| 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.
| mynegation wrote:
| 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 wrote:
| 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 180deg.
|
| 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 wrote:
| 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 wrote:
| 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 wrote:
| > 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 wrote:
| 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.
| kbelder wrote:
| Yeah, I'm sure you're right. I was looking purely at
| orbital mechanics and gravity, but I think a four-
| stellar-mass black hole would certainly have other
| harmful environmental effects that would be felt at that
| range.
| trollbridge wrote:
| Destabilise 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 wrote:
| 5AU seems incredibly close. That's inside the orbit of
| jupiter. How would it not destabilize the entire system?
| 98codes wrote:
| > extremely unlikely
|
| But never zero.
| Zigurd wrote:
| 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 wrote:
| 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 wrote:
| Concern for celestial events is a bit like one of your gut
| bacterium being concerned with your work schedule
| vkazanov wrote:
| These little guys often do get a hammering on fridays...
| thisisauserid wrote:
| The "Great Filter" answer to the Fermi Paradox.
| stronglikedan wrote:
| 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.
| cousinbryce wrote:
| 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?
| pavel_lishin wrote:
| For the latter, you mught enjoy Greg Egan's "Perihelion
| Summer".
| antognini wrote:
| 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.
| jandrewrogers wrote:
| 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.
| shagie wrote:
| How to spot tiny black holes that might pass through the
| solar system -
| https://www.sciencenews.org/article/primordial-black-
| holes-s...
|
| And the referenced papers:
|
| Probing primordial black holes and dark matter clumps in the
| Solar System with gravimeter and Global Navigation Satellite
| Systems networks - https://journals.aps.org/prd/abstract/10.1
| 103/PhysRevD.110.0...
|
| Close encounters of the primordial kind: A new observable for
| primordial black holes as dark matter - https://journals.aps.
| org/prd/abstract/10.1103/PhysRevD.110.0...
|
| And the PBS Spacetime: How Many Black Holes Are In The Solar
| System? - https://youtu.be/wh75ubECL8I
| SoftTalker wrote:
| Wouldn't low-mass primordial black holes have evaporated by
| now?
| jfengel wrote:
| Depends on what "low mass" means. An earth-mass black hole
| lasts 10^50 years. A black hole the mass of Mount Everest
| lasts 10^21 years.
|
| Black holes on the order of metric tons would have
| evaporated by now. But primordial black holes can come in
| any size, and there is a vast range of them that will exist
| much longer than the universe has already existed.
| Tuna-Fish wrote:
| Note that the orbital perturbation of Juno in 1839 was of
| rather low magnitude, and could have been caused by an
| asteroid as small as ~1km diameter. Based on current models,
| there are potentially more than a million rocks that big in
| the belt still undiscovered.
| temp0826 wrote:
| 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 wrote:
| I think at the energy scales we're talking about, everything
| involved would basically act like a fluid.
| xyzzy_plugh wrote:
| This is correct, the Earth is effectively a ball of water,
| and would get blended/smeared/sheared like if you toss
| water across a yard out of a cup.
| boesboes wrote:
| 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..
| sgt101 wrote:
| 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 wrote:
| 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.
| Schlagbohrer wrote:
| 3-Body-Problem once again vindicated as the scariest possible
| explanation for the Fermi Paradox
| criddell wrote:
| Did you intend to say _dark forest hypothesis_?
| Schlagbohrer wrote:
| Yes!
| istjohn wrote:
| According to physicist Sean Carroll, "hypothesis" and
| "theory" are interchangeable as the words are used by
| practicing scientists.
| rigrassm wrote:
| 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 wrote:
| Isn't Planck's hypothesis really a theory? Isn't string
| theory really a hypothesis?
| marcosdumay wrote:
| It seems to relate much more to the size of the proposal
| than to its confidence.
|
| Even more because the confidence changes all the time, but
| people do go around renaming well known ideas
| 9dev wrote:
| 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 wrote:
| 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.
| Vvector wrote:
| https://www.noahpinion.blog/p/the-dark-forest-hypothesis-
| is-...
| xenophonf wrote:
| That link is paywalled.
|
| This might be a better one.
|
| https://medium.com/predict/why-the-dark-forest-theory-is-
| pro...
|
| This video is pretty good.
|
| https://www.youtube.com/watch?v=X0SvgT9Lc2M
|
| This post attempts a formal refutation.
|
| https://www.pgmusings.ca/journal/dfh
| graemep wrote:
| What flaws? Do they apply to variants such as Greg Bear's and
| related ideas such as berserkers?
| pavel_lishin wrote:
| Do Forge of God/Anvil of the Stars differ significantly
| from pretty bog-standard dark forest scenarios?
|
| I don't remember any other of his books that might apply,
| but I haven't read all of them. (I probably should. What I
| have read was great.)
| graemep wrote:
| its a few years since I read Liu Cixin's books and even
| longer since I read Greg Bear's, but the technology was
| very different, and it was not as uniformly hostile. The
| primary technology used to destroy civilisations in
| Bear's books was self-replicating machines, and there was
| an advanced civilisation that tries to defend or rescue
| those attacked, and punish the aggressors - so its a bit
| less bleak.
| cyberax wrote:
| "Dark forest" doesn't work from a game-theoretical
| standpoint. It assumes that it's cheap to destroy entire
| planets and solar systems. Yet no-one seems to be
| colonizing other systems.
|
| The optimal strategy in this case is to expand as quickly
| as possible, before others can grab or destroy resources.
| idontwantthis wrote:
| I think one idea is that there aren't very many habitable
| planets. The Trisolarians are coming to Earth because
| it's their only option, not because they want to destroy
| humanity.
| cyberax wrote:
| Then it's even weirder. Detecting planets around stars is
| trivial, yet nobody is running to get that prime real
| estate?
|
| Still makes no sense.
| bpodgursky wrote:
| Why would physicists have anything useful to say about this
| theory?
| 59percentmore wrote:
| Because environment makes culture and physics are the
| environment at relativistic speeds and cosmic distances.
| Schlagbohrer wrote:
| Culture at some level grows out of biology and physics,
| it's downstream of those things. The material basis of a
| civilization will have a tremendous long term impact on its
| culture.
| EA-3167 wrote:
| There are loads of issues with it as hard sci-fi, but the
| bigger issue is that it's meant as a political allegory far
| more than it's meant to be hard sci-fi. Where I think it
| shines to some extent in the latter case is its ability to
| explore scale and build intuition about the vast scales
| involved in space.
|
| Otherwise though? Sophons destroy the entire premise of the
| "Dark Forest"! Still as I said the series is far more
| concerned with overt allegories (West vs East, Collectivism
| vs Individualism, etc), and more covert allegories that
| allegedly criticize the CCP's way of doing things.
|
| I don't read Mandarin, but I suspect the ability to do so and
| the high context nature of the language, helps a lot in
| getting that across.
| echelon wrote:
| 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".
| alansaber wrote:
| 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.
| WarmWash wrote:
| Every year the IQ needed to destroy the world drops by 1
| point.
| SoftTalker wrote:
| 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.
| andrewflnr wrote:
| 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.
| echelon wrote:
| You don't know any of that.
|
| We are primitive apes. We are all uniformly dumb.
| andrewflnr wrote:
| 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 wrote:
| > 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 wrote:
| > > 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.
| strogonoff wrote:
| All we can say is that the universe has been consistent
| so far, during the brief time we observed a small part of
| it given the instruments we have.
|
| We update our model(s) so that it keeps being consistent
| and predictable to us (that's human nature), but no model
| can be probably correct and complete.
| andrewflnr wrote:
| You are not grappling with the full consequences of the
| universe being inconsistent. If the universe is
| inconsistent, science is dead. Why the fuck on HN of all
| places do I need to defend the idea that science is
| possible? Back to philosophy class, all of you.
| ButlerianJihad wrote:
| 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/
| andrewflnr wrote:
| In what way? This is discussing, as far as anyone knows, an
| entirely natural phenomenon.
| etangent wrote:
| suspecting that star explosions are caused by nefarious super-
| intelligences is just Greek mythology with more steps.
| raiyanr wrote:
| when will sun be exploaded?
| Y-bar wrote:
| More than eight minutes ago. At least.
| aklemm wrote:
| And yet no one does a thing about it.
| CookieCrisp wrote:
| What would you like done?
| PowerElectronix wrote:
| Be the change you want to see in the world. Go out there and
| start swatting away nanoscopic black holes.
| choboswaggings wrote:
| 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 wrote:
| 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.
| YetAnotherNick wrote:
| 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
| shagie wrote:
| 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.
| cyberax wrote:
| Not really? They would likely pass through Earth completely
| invisibly.
| ungovernableCat wrote:
| 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.
| shagie wrote:
| Not quite so undetectable... in theory.
|
| PBS Spacetime - How Many Black Holes Are In The Solar System?
| https://youtu.be/wh75ubECL8I
|
| And then How to spot tiny black holes that might pass through
| the solar system -
| https://www.sciencenews.org/article/primordial-black-
| holes-s...
|
| That references two papers:
|
| Probing primordial black holes and dark matter clumps in the
| Solar System with gravimeter and Global Navigation Satellite
| Systems networks - https://journals.aps.org/prd/abstract/10.1
| 103/PhysRevD.110.0...
|
| Close encounters of the primordial kind: A new observable for
| primordial black holes as dark matter - https://journals.aps.
| org/prd/abstract/10.1103/PhysRevD.110.0...
| brabel wrote:
| [flagged]
| ck2 wrote:
| 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
| mmmBacon wrote:
| Sounds like PMH, if they exist, are essentially the Universe's
| ultimate cannonball.
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