Inside Out: The Possibility of White Holes and Black Holes Within Each Other

[BATMANofPHYSICS]

hypothetically speaking, are white holes inside white holes possible?
and also, are black holes inside black holes possible?

 

[jfizzix]

It may be literally impossible to test for what goes on inside the event horizon of a black hole, so there's probably no way of knowing.

But...

If there's an expert in General Relativity willing to comment, an alternative question would be, in the Schwarzschild metric, can spherical shells of negative mass (or some other such thing) within the event horizon of one black hole, make the local curvature flat enough that you can meaningfully talk about a second event horizon further down?

Maybe one way of thinking about it would be to say whether such a shell would allow you to arrest your descent if you had a relativistic orbital velocity?

I know very little about General relativity, so I can't comment beyond that.

 

[phinds]

I have read it here several times that when black holes merge, the result is just a bigger black hole. there is no way to form a black hole inside a black hole.

White holes are generally considered to be a mathematical oddity with no physical reality.

 

[jfizzix]

Indeed, negative mass is a mathematical oddity.