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Could white holes actually exist? (www.space.com)

submitted 2 years ago by readbeanicecream@kbin.social to c/space@kbin.social

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White holes are mathematically possible, according to general relativity. But does that mean they're actually out there?

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[–] exscape@kbin.social 4 points 2 years ago (10 children)

I'm also no authority, but I strongly disagree that "it follows" that the stuff must be coming out.
We know that stuff enters black holes, and we know that they gain mass when it does. We think they shrink in mass over extreme periods of time, but other than that, I'm fairly sure we've never seen a black hole lose mass.

So if the mass comes out in a white hole, why does the black hole retain its mass?
I haven't read the book but I can't imagine he says, without strongly stating that it's very speculative, that such a thing could happen.

[–] sparseMatrix@kbin.social 1 points 2 years ago (9 children)

@exscape

@readbeanicecream

By definition, a manifold has a place where things go in, and other things come out. So yes, it does in fact logically follow. If its a manifold, then it logically follows that what goes in comes out.

You're saying we know a bunch of stuff I'm not certain we know.

My understanding is that by definition, the singularity has infinite mass and infinite gravity, so there is no way it can gain mass; because infinity + 1 = infinity. It's the very nature of infinities. You can have a number of infinities, but manipulating them arithmetically always yields infinity. 2 x infinity = infinity. 3 / infinity = infinity.

Like zero, it is more identity than number. 0 = nothing, infinity = everything.

So if you hope to have me follow your narrative, you're going to address this assertion concerning increasing the mass of black holes first.

[–] FfaerieOxide@kbin.social 1 points 2 years ago (1 children)

the singularity has infinite mass and infinite gravity, so there is no way it can gain mass; because infinity + 1 = infinity. It's the very nature of infinities. You can have a number of infinities, but manipulating them arithmetically always yields infinity. 2 x infinity = infinity. 3 / infinity = infinity.

Can't infinities be different sizes, though?

[–] sparseMatrix@kbin.social 1 points 2 years ago

@FfaerieOxide

@readbeanicecream @exscape

Thank you for linking that! I knew I had read that they could be, but I couldn't recall where. It might not have been Scientific American, but that'll do XD

While clearly they can be, infinity == infinity is still true, If I recall.

Also, I've got some simple problems with that crate analogy, Scientific American or not; any crate with an infinite number of anything inside it cannot be emptied, it's in the very definition of infinite. Consequently, neither crate will ever empty and the pairing will be an infinite pairing of apples and oranges.

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