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pinguin_skipper t1_j6sujzt wrote

Physics: could something escape a black hole if that object would somehow reach a speed higher than current limit(c)? Or it is a nature of a black hole that nothing can escape, no matter the speed?

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HonoraryCanadian t1_j6tjdiu wrote

IANAP, but the way I heard it explained is that a black hole bends space-time so much that a straight line curves back into itself as a circle. Thus light fails to escape not because it lacks enough speed, but because there is no straight line it can follow that exits the black hole.

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turgidNtremulous t1_j6ts7cp wrote

Yeah, inside the event horizon, no matter which direction you look, you are looking at the singularity (whatever that looks like, which no one knows). That has always tripped me out.

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rayschoon t1_j6wv4vu wrote

Imagine you’re standing on a globe and on the other side there’s a point (the singularity). Every direction you walk is towards the singularity. It’s kinda like that but with another dimension

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An_Average_Player t1_j6tfkma wrote

Theoretically, maybe? The biggest problem with that is that you can't physically get faster than that, even theoretically

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Varsect t1_j6u2v30 wrote

That's not possible theoretically either. The geometry of black holes makes it that the speed needed to escape is basically ∞. All pathways simply lead inside. There is no “theoretically.”

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cygx t1_j6ugvjm wrote

There is a 'theoretically': Tachyons would be able to cross event horizons.

Of course, we have no reason to believe that tachyons exist (and good reasons to believe why they don't), but if you're not careful, they may pop up in numerical simulations (that whole photon velocity being a null vector thing is a bit fragile if you do not take steps to enforce it algorithmically).

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mfb- t1_j6vn9tk wrote

To reach a speed faster than light relativity needs to be wrong. Asking what relativity predicts in situations where it doesn't apply is meaningless. You could ask the question in a completely different framework, e.g. in Newtonian physics (where motion faster than light is possible), but then you don't have black holes any more so you run into the same problem of the question having no answer.

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rayschoon t1_j6wv92u wrote

In Newtonian physics as long as you have a constant force you can accelerate forever, right?

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EnchantedCatto t1_j6u0w7g wrote

Its not really due to a speed requirement, but the curvature of spacetime. Black holes bend spacetime so much that any path sort of wraps around back to the singularity.

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zarro110 t1_j6tlfay wrote

Our current understanding would technically allow something that goes faster than the speed of light to get out of the event horizon, as that exists due to the speed of light. However a lot of things will be broken in physics if such an object exists and we don't think they do.

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Varsect t1_j6u2m0n wrote

No. The geometry of black holes is curved that every direction leads to the singularity. Unless that speed was ∞, no.

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