Yes i think it is even quite sensible to consider the possiblity of this universe being contained by a giant blackhole.
This universe(as it is known) is generally considered to be expanding (excentric movement), whereas a blackhole
ultimately is a concentric movement.

A universe only has to be smaller than what is around it, and there is no doubt more than one way for a universe to exist. The universe we exist in could just be a flash, and we think it is taking billions of years, because we don't have anything but what is in this dimension to compare...Yet

Fzzzzzzzzzzzzzzzzzzzzzz pop!

My head's just exploded!!!

The universe we exist in could just be a flasht

a very coherent flash at that but nonetheless yes just a bleep.
For myself i understand it(the duration of the flash) as a sinuswaveform within a larger sinuswaveform hence i find the use of the word multiverse far more accurate then universe.