(Submitted October 27, 2001)
I once read that there was a theory that a black hole could be
connected to a white hole. Does that the theory have any validity?
Also, if that theory is valid, that does that mean anything that falls
into a black hole is ejected from a white hole? And where will this
matter be ejected into? Another galaxy or another universe (if that
exists)? Also, are black holes connected with hyperspace?
Thank you for your question. It is mathematically possible, in the case
of rotating black holes, for there to be a black hole and white hole
connected by a wormhole. It is questionable whether such objects
could form in actuality and, if they did form, whether they would be
stable. If they did exist, anything falling into such a black hole
would indeed be ejected from a white hole (after experiencing some
extreme physical conditions) -- possibly in a distant region of
spacetime (possible in the past or future), or even in another
universe. However, there is no observational evidence for white holes.
-- Michael Loewenstein and Amy Fredericks
for "Ask an Astrophysicist"