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Posted by jandrewrogers 2 days ago

Tiny black holes may be exploding stars across the Milky Way(www.sciencedaily.com)
https://iopscience.iop.org/article/10.3847/1538-4357/ae6db7
96 points | 98 commentspage 2
empath75 1 day 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 1 day 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 1 day 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 day ago|||
Concern for celestial events is a bit like one of your gut bacterium being concerned with your work schedule
vkazanov 1 day ago||
These little guys often do get a hammering on fridays...
trollbridge 1 day 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 1 day 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 day 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 day ago||||
5AU seems incredibly close. That's inside the orbit of jupiter. How would it not destabilize the entire system?
mynegation 1 day 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 day 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 day 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 day 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.
kbelder 1 day 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.
ben_w 1 day 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 1 day 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.

cindyllm 1 day ago||
[dead]
98codes 1 day ago|||
> extremely unlikely

But never zero.

brabel 1 day ago||
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gigatexal 22 hours ago||
No no no ... they're Monoliths from 2001: A Space Odessy, remember when he became one and would go from star to star blowing them up for fun?
BedVibe_Studios 1 day ago||
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raiyanr 1 day ago|
when will sun be exploaded?
Y-bar 1 day ago|
More than eight minutes ago. At least.