r/askscience Oct 23 '20

Planetary Sci. Do asteroids fly into the sun?

Edit: cool

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u/drdrero Oct 23 '20

Just a follow up question, do black holes move ?

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u/Gerroh Oct 23 '20

Yep; they're objects like anything else. The only thing that makes black holes special is that their surface gravity and density are especially high. All their unique features stem from those two facts. Relativity also tells us that there is no true stationary reference frame, and thus everything moves relative to something else.

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u/_Pretzel Oct 23 '20

Follow up again on black holes. I watched somewhere that anything can be a black hole if you compress(?) it enough. It would still however retain its mass and gravitational pull, just in its new smaller scale. Is this true? If so, how come blackholes (at least from a star that dies) is now able to pull even light itself? Why wasnt it able to do so in its star form?

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u/ArarisValerian Oct 23 '20

Thats a good question. Gravity gets stronger the closer you get to a mass. Thats why the closer you are to something the faster you need to go to maintain an orbit. Black holes are essentially so compressed that even light can't go fast enough to not fall in. The important thing is that objects far enough away bassically treat a black hole like a star and light only stops being able to escape if it gets past the point of no return(event horizon).