: : Therefore couldn't our entire universe as we know it be trapped inside a giant black hole? Or would it be impossible to have a blackhole inside a blackhole?

: My dear boy have you ever tried to dig a hole inside the empty space of the hole? well unless : your eternal plan was to shovel air it cant be done. a hole cant become a : hole squared because it isnt a whole and I do meen whole.

Hey kahuna man, a black hole is a region of space-time which is cut off, from the space-time in which it formed. So, it is logical that in this cut off space-time region that black holes could form.

Whose to say that our universe isn't in a region of spacetime which was cut off from some other region, and that there is a singularity in the centre of our universe. This isn't so far fetched because did you know that our galaxy along with many others seem to form a river of glaxies heading to towards some 'great attracter'. It is thought that in around 75 billion years our galaxy will be part of a super super-cluster of galaxies orbiting this great attractor.

So big kahuna, open your mind a little, explore possibilities before dismissing them, because until they are proven wrong they may be right.