Black Hole Questions

[HeeHomeboyMokey]

from what I have seen, this has not been asked yet (looked over the page a few times and checked relevant threads with the Black Hole Feats in Fiction tag)

if an object behaves and looks like a black hole in a fiction but is not referred to as one, would it be considered a black hole regardless?

also, I've noticed E = mc^2 used to be used for black hole creation calcs, but it isn't in every case. Is that just a dated standard or am I missing something? Is it because the black hole is below five solar masses maybe? (Which is what would legitimately create a black hole irl iirc)

Both are sort of relevant to a thread i have going on, but more so the first question is the important one.

 

[HeeHomeboyMokey]

Bump

 

[Reppuzan]

To answer your first question, it would need to display most of the properties of a black hole for it to be considered one. So an event horizon that light can't escape e.t.c.

 

[CNBA3]

Would stretching matter in a spaghettification like fashion be one? Or described as an infinite gravity well?

 

[Reppuzan]

@CNBA3

Yes to both of those things.

 

[HeeHomeboyMokey]

Would anyone know the reason behind the second one then? Are calcs that used to use E=mc^2 for black hole creation then obsolete, or is there something I am missing?

 

[Reppuzan]

@Nekroz

I'm not exactly a math person, so I don't know the exact reasoning why it isn't used anymore, but I believe it was because E=mc^2 was used under the basis of "Mass requires energy and thus creating a black hole out of nothing requires the use of a proportional amount of energy". But since most black holes are not created that way in fiction, the use of E=mc^2 was discontinued.

 

[HeeHomeboyMokey]

That makes sense, thank you