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Tiny black holes may be exploding stars across the Milky Way

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Re: Tiny black holes may be exploding stars across the Milky Way

#51

Post by andrewflnr »

echelon wrote: post #47
andrewflnr wrote: post #46

Earlier quoted context omitted.

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…

You don't know any of that. We are primitive apes. We are all uniformly dumb.

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.

Re: Tiny black holes may be exploding stars across the Milky Way

#53

Post by ben_w »

bell-cot wrote: post #41
kbelder wrote: post #31

Earlier quoted context omitted.

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.

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.

> 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".

Re: Tiny black holes may be exploding stars across the Milky Way

#54

Post by jandrewrogers »

cousinbryce wrote: post #5

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?

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.

Re: Tiny black holes may be exploding stars across the Milky Way

#55

Post by YetAnotherNick »

ttul wrote: post #36
choboswaggings wrote: post #26

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.

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.

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

Re: Tiny black holes may be exploding stars across the Milky Way

#56

Post by echelon »

andrewflnr wrote: post #51
echelon wrote: post #47

Earlier quoted context omitted.

You don't know any of that. We are primitive apes. We are all uniformly dumb.

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.

> 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.

Re: Tiny black holes may be exploding stars across the Milky Way

#57

Post by rigrassm »

istjohn wrote: post #45
criddell wrote: post #13

Earlier quoted context omitted.

Did you intend to say dark forest hypothesis ?

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

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.

Re: Tiny black holes may be exploding stars across the Milky Way

#58

Post by [deleted] »

ungovernableCat wrote: post #43
choboswaggings wrote: post #26

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.

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.

[deleted]

Re: Tiny black holes may be exploding stars across the Milky Way

#59

Post by temp0826 »

cousinbryce wrote: post #5

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?

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 :/

Re: Tiny black holes may be exploding stars across the Milky Way

#60

Post by bell-cot »

ben_w wrote: post #53
bell-cot wrote: post #41

Earlier quoted context omitted.

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.

> 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".

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.

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