No one knows for sure, not even physicists have a good idea. As yet we do not have a theory of gravity (called by physicists quantum gravity theory) that can take us beyond the Singularity state predicted by general relativity. Physicists are convinced that this state is not real, but only a sign that our theory has broken down, so until physicists can fashion a reliable and experimentally-verifiable theory of quantum gravity, we cannot make any firm predictions. However, some physicists including Stephen Hawking believe that matter entering a black hole in our universe, will emerge as matter spewed forth from a so-called white hole in another universe. The mathematics seem to say this, but there are many difficulties in interpreting such theories without knowing whether they are accurate representations of our physical world.

An intriguing idea has recently been proposed by physicist Lee Smolin. He says that it is very difficult for a universe to create black holes (such as by stellar evolution) unless the universe has just the right physical laws and constants of nature tuned properly. Such universes will be able to replicate themselves very efficiently, and numerously, by the Hawking process. Each black hole formed in a 'proper' universe will spawn a new universe with similar physical conditions. If true...but impossible to prove...universes like ours, over enough time, will become the commonplace cosmos, which also means that universes with living systems may become very common!

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