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clocks212 t1_j26hnaj wrote

Reply to comment by amaurea in How fast does the Milky Way spin? How far does Earth move through space in a year? by Sabre-Tooth-Monkey

I’ve searched before but never found an answer, maybe you know. Could you be close enough to merging black holes to feel/be killed by the gravitational waves without already having been killed by the black hole or its accretion disk?

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Kantrh t1_j26scg5 wrote

Possibly. According to this article https://www.forbes.com/sites/startswithabang/2020/02/15/ask-ethan-could-gravitational-waves-ever-cause-damage-on-earth.

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Onetime81 t1_j28r1du wrote

If death didn't occur until after crossing the event horizon, then this would be the best way to die, imo

As you cross you'd be able to watch the universe age and die. You'd get a conclusion to the story... Right before you cells started to unmesh themselves from your body.

Trade offs, amirite ¯⁠\⁠⁠(⁠ツ⁠)⁠⁠/⁠¯

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Theban_Prince t1_j290xqy wrote

Would you just freeze in time halfway there? Meaning even ypur brain will not be able to perceive anything.

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Onetime81 t1_j2a5z34 wrote

Depends on your perspective, naturally, with spacetime being relative and all.

From an observers pov, say comrades who couldn't catch you in time, you would freeze for forever, until you the light bouncing off you slowly redshifted out of our visual range. Which sounds awful to experience, even just watching.

On the plus side, you would allow accurate mapping of where the horizon actually is, since it's invisible, the moment you 'froze' would be the moment when you crossed over.

From you're pov its speculated that at that distance you'd essentially be outside time. And past the horizon light only goes one way, and that's in towards the black hole, which you wouldn't be facing, so you'd see all of the light from all time descending towards you. Whether that's linear, and just like a VCR on fast forward, that I can't say, and I don't know if that will or would ever be verified.

So you'd get the answers of how it all ends (heat death, big crunch, cyclical, neuvo-physics bubble, great unraveling, grey goo, thetons, who knows) but you'd never be able to share the answers... Unless each black hole IS an Einstein-Rosen Bridge.

I like to think hidden behind each horizon is a great cosmic/galactic space-truck stop full of alien yokels. That's the flavor of multiverse I want to be in :)

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TripleJeopardy3 t1_j2a52ei wrote

If that happens you should power cycle and reboot. So maybe take a nap and when you wake up your brain will work again.

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clocks212 t1_j2dyrqf wrote

Only from an outsiders perspective would you freeze. From an outsiders perspective a black hole can be thought of as “a region of space where nothing has ever happened”. From your perspective you would just fall straight through the event horizon like nothing was there until you were killed by gravitational forces or impacted whatever exists at the center of the black hole.

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StandardSudden1283 t1_j26ilsf wrote

I want to add on to this question - would the answer to the above be different if the black hole had no accretion disk?

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Lurker_IV t1_j29j0d0 wrote

If you get too close to the wrong black hole then you become its accretion disk...

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tomrlutong t1_j29gfae wrote

I did the math a while back- you have to be crazy close, like 100s of km, to a merger for the gravity waves to affect you directly. /u/StandardSudden1283 Even a 'cold' pair of BHs (no accretion disk) would kill you from tidal forces at a much greater distance.

The article/u/kanrith links to suggests the waves could cause earthquakes or something on the planet you're on, and so indirectly hurt you, but its not verry convincing.

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