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What would happen if a small black hole fell into a star?

All of the answers here deal with the black hole eating matter as if nothing else happens in the process. This is plain wrong. Black holes (well, it is the space neighboring them) are the brightest ...
fraxinus's user avatar
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5 votes

What would happen if a small black hole fell into a star?

The existing answers haven't really addressed your point 2, so I'll cover that here. The possibly-surprising thing is that it's basically impossible to shoot a black hole at a star such that it won't ...
N. Virgo's user avatar
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11 votes

What would happen if a small black hole fell into a star?

@AndersSandberg's answer surprised me so I wanted to poke around some more, to see what could a determined attacker achieve. So here's what would happen if we put a BH in orbit inside a star so that ...
Filip Sondej's user avatar
31 votes
Accepted

What would happen if a small black hole fell into a star?

How much matter can a small black hole absorb? This determines the answer to your questions. A simple approximation is that moving black holes absorb everything they pass through out to a radius $kR_S$...
Anders Sandberg's user avatar
11 votes
Accepted

Could an hypothetical hidden black hole companion to the sun be revealed by proper motion data?

A black hole at a distance of 10,000 AU (comparable to the separation of Proxima from Alpha Centauri) could mean that the sun was in an orbit lasting longer than 200,000 years. So in two hundred years,...
James K's user avatar
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3 votes

How could lithium burning take place in a quasi-star?

If present, lithium is burned at lower temperatures than hydrogen (protium), although at higher temperatures than deuterium. See Why does lithium fuse at lower temperatures than hydrogen? The ...
ProfRob's user avatar
  • 146k
-1 votes

Can a small black hole orbit a large star?

It's already there. M33 X-7 blackhole orbits its companion star in 3.5 days.
Voltage Source's user avatar
3 votes

The consequences and the mechanisms of a shift of the Earth away from the sun

Your idea of a planetary-mass black hole is on track. The real challenge here is that the black hole only gets one chance to change the orbit as it passes through the solar system. It would definitely ...
Mark Foskey's user avatar
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0 votes

Why do we not call black holes black stars or dark stars?

In theory, if you could observe the gravitational collapse of a star, you'd see it accelerating away from you regardless of what direction you observed it from. Just as if it fell into a hole. This is ...
John Doty's user avatar
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0 votes

Is there a maximum size for a black hole?

I believe there’s a limit on the size of a blackhole. Since the universe is expanding at a rate of approximately 70km/s/megaparsec then that implies that if you had a blackhole that was about 14 ...
Matt Williams's user avatar
7 votes

Why do we not call black holes black stars or dark stars?

The hypothetical object where gravity is so strong that even light cannot escape was indeed first called "dark star". It was first named as such by John Michell in the 1700s. See Wiki. Note ...
Allure's user avatar
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-2 votes

Would gravitational waves be subject to external gravitational perturbations?

This question is difficult to answer. If GW behave like "normal" waves, obstacles in the inner Fresnel zone are the main nuisance. The diameter of possible objects should be larger than $\...
9herbert9's user avatar
2 votes

How can Kerr black holes have a 'speed limit' to how fast they can spin?

As an addendum to @Anders Sandberg's excellent answer: The maximum limit on the spin is a consequence of two (not fully proven) conjectures that each imply the existence of this limit individually. ...
TimRias's user avatar
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6 votes

How can Kerr black holes have a 'speed limit' to how fast they can spin?

Yes, general relativity does not contain anything preventing spacetime from expanding or moving superluminally (e.g. "warp drive spacetimes"): normally other constraints (e.g. the lack of ...
Anders Sandberg's user avatar
1 vote

How can Kerr black holes have a 'speed limit' to how fast they can spin?

Spin too fast and you have a "naked" singularity Basically, yeah, that's exactly what's limiting the rotational speed of a black hole. Rotating black holes, also known as Kerr black holes, ...
Furious Arcturus's user avatar
0 votes
Accepted

Can black holes even exist [if mass cannot be retained near the collapse threshold]?

I have been made aware of the aforementioned 'missing important information' by way of a helpful video I was referred to earlier. As I now understand, it is not the strength of atomic structures (...
hamstar's user avatar
  • 103
6 votes

Can black holes even exist [if mass cannot be retained near the collapse threshold]?

A different way of looking at the issue: what properties would matter need to have to avoid imploding into a black hole if enough matter was gathered in a static sphere? The key thing about black ...
Anders Sandberg's user avatar
4 votes

Can black holes even exist [if mass cannot be retained near the collapse threshold]?

Gravity doesn't care at such extreme conditions. Yeah, I am definitely not joking. Friction, nuclear fission and whatever forces are there in the core of a massive dying star have no chance against ...
Furious Arcturus's user avatar

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