Zap: "One thing I've always wondered is that our universe is just one out of many thriving inside one gigantic 'superuniverse'."

There have been speculations about this. One example: suppose black hole singularities can start new big bang universes in sets of dimensions separate from ours--some of these universes would be governed by physics which also allow black hole singularities to form, and these would seed new universes ad infinitum. If we could tally this array of universes from some impossible extra-dimensional viewpoint, we might find no sign of an ultimate beginning, no prospect of an end.

Others have speculated that the inflationary epoch has only collapsed in our particular region of the big bang universe--a region which, however, might still be larger than 10¹⁰ times our current visible horizon--and in other regions the collapse of inflation may have resulted in certain different physical constants. The physical universe we know may be one bubble in a larger, more diverse multiverse; in fact, depending on the details of the collapse of the false vacuum, some have speculated that inflation will, in a larger sense, never end; and we find ourselves in one of a near-infinite number of bubbles of "plain vanilla" vacuum in which the false vacuum has collapsed but there are more such bubble-universes coming into existence all the time in the exponentially-expanding super-universe.

This is speculation, though, and possibly something that beings operating inside a coherent region of spacetime with set physical laws can never possibly test.