Tiny black holes may be exploding stars across the Milky Way

Posted by jandrewrogers 1 day ago

https://iopscience.iop.org/article/10.3847/1538-4357/ae6db7

Comments

Comment by sgt101 15 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...

Comment by antognini 14 hours 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.

Comment by Schlagbohrer 15 hours ago

3-Body-Problem once again vindicated as the scariest possible explanation for the Fermi Paradox

Comment by 9dev 15 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.

Comment by Schlagbohrer 15 hours 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.

Comment by Vvector 9 hours ago

https://www.noahpinion.blog/p/the-dark-forest-hypothesis-is-...

Comment by xenophonf 3 hours ago

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

Comment by graemep 14 hours ago

What flaws? Do they apply to variants such as Greg Bear's and related ideas such as berserkers?

Comment by pavel_lishin 13 hours ago

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.)

Comment by graemep 12 hours ago

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.

Comment by cyberax 6 hours ago

"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.

Comment by idontwantthis 6 hours ago

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.

Comment by cyberax 6 hours ago

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.

Comment by EA-3167 8 hours ago

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.

Comment by bpodgursky 14 hours ago

Why would physicists have anything useful to say about this theory?

Comment by 59percentmore 14 hours ago

Because environment makes culture and physics are the environment at relativistic speeds and cosmic distances.

Comment by criddell 15 hours ago

Did you intend to say dark forest hypothesis?

Comment by istjohn 14 hours ago

According to physicist Sean Carroll, "hypothesis" and "theory" are interchangeable as the words are used by practicing scientists.

Comment by rigrassm 13 hours 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.

Comment by criddell 13 hours ago

Isn't Planck's hypothesis really a theory? Isn't string theory really a hypothesis?

Comment by marcosdumay 7 hours ago

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

Comment by Schlagbohrer 15 hours ago

Yes!

Comment by etangent 14 hours ago

suspecting that star explosions are caused by nefarious super-intelligences is just Greek mythology with more steps.

Comment by andrewflnr 14 hours ago

In what way? This is discussing, as far as anyone knows, an entirely natural phenomenon.

Comment by echelon 15 hours 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".

Comment by andrewflnr 14 hours 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.

Comment by ButlerianJihad 13 hours 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/

Comment by echelon 14 hours ago

You don't know any of that.

We are primitive apes. We are all uniformly dumb.

Comment by andrewflnr 14 hours 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.

Comment by echelon 13 hours 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.

Comment by andrewflnr 13 hours 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.

Comment by strogonoff 7 hours ago

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.

Comment by andrewflnr 4 hours ago

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.

Comment by alansaber 14 hours 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.

Comment by SoftTalker 13 hours 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.

Comment by WarmWash 14 hours ago

Every year the IQ needed to destroy the world drops by 1 point.

Comment by cousinbryce 15 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?

Comment by jandrewrogers 13 hours 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.

Comment by Tuna-Fish 13 hours ago

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.

Comment by shagie 13 hours ago

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/10.1103/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

Comment by SoftTalker 13 hours ago

Wouldn't low-mass primordial black holes have evaporated by now?

Comment by jfengel 10 hours ago

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.

Comment by pavel_lishin 15 hours ago

For the latter, you mught enjoy Greg Egan's "Perihelion Summer".

Comment by antognini 14 hours 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.

Comment by temp0826 13 hours 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 :/

Comment by pavel_lishin 13 hours ago

I think at the energy scales we're talking about, everything involved would basically act like a fluid.

Comment by xyzzy_plugh 9 hours ago

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.

Comment by ButlerianJihad 15 hours ago

[flagged]

Comment by Quinner 15 hours ago

Perhaps you meant to read the https://news.ycombinator.com/newsguidelines.html about comments being kind, not snarky, and substantive.

Comment by 15 hours ago

Comment by mmmBacon 2 hours ago

Sounds like PMH, if they exist, are essentially the Universe’s ultimate cannonball.

Comment by thisisauserid 15 hours ago

The "Great Filter" answer to the Fermi Paradox.

Comment by stronglikedan 15 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.

Comment by choboswaggings 15 hours 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.

Comment by ttul 14 hours 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.

Comment by shagie 13 hours 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.

Comment by YetAnotherNick 13 hours 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

Comment by cyberax 12 hours ago

Not really? They would likely pass through Earth completely invisibly.

Comment by ungovernableCat 14 hours 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.

Comment by shagie 13 hours ago

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:

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...

Comment by 13 hours ago

Comment by boesboes 15 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..

Comment by ck2 13 hours 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

Comment by aklemm 15 hours ago

And yet no one does a thing about it.

Comment by PowerElectronix 14 hours ago

Be the change you want to see in the world. Go out there and start swatting away nanoscopic black holes.

Comment by CookieCrisp 14 hours ago

What would you like done?

Comment by empath75 15 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.

Comment by Zigurd 15 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.

Comment by OneDeuxTriSeiGo 15 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...

Comment by alansaber 14 hours ago

Concern for celestial events is a bit like one of your gut bacterium being concerned with your work schedule

Comment by trollbridge 15 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.

Comment by ben_w 15 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.

Comment by trollbridge 14 hours 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.)

Comment by 14u2c 14 hours ago

5AU seems incredibly close. That's inside the orbit of jupiter. How would it not destabilize the entire system?

Comment by mynegation 15 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.

Comment by ben_w 15 hours 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.

Comment by kbelder 14 hours 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.

Comment by bell-cot 14 hours 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.

Comment by kbelder 6 hours ago

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.

Comment by ben_w 13 hours 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".

Comment by bell-cot 13 hours 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.