[thedoc (OP)]

Josip Buric asked the Naked Scientists:
   Are there universes like ours? Are there more universes and do they float like bubbles in 'nothing'?
What do you think?

[jerrygg38]

   Assuming that the big bang is true, then our universe is self contained. Everything that exists as far as we are concerned is within the total gravitational field of the universe. What lies beyond our universe? There could be nothing at all. Likewise there could be billions of billions of other self contained universes. Between them could be pure nothingness with no gravitational fields. There could also be universes of an infinity of different light speeds. We might even have interconnections at higher light speeds.
   There are infinite possibilities but if we are truly self contained, we can never know.

[yor_on]

Dosen't matter, does it?

Make this one first, then the others

[evan_au]

Are there other universes like ours?

If our 4-dimensional universe (3 dimensions of space + 1 of time) is embedded in some higher-dimensional space, then there are various ways our universe could collide or interact with other universes.

There is no solid evidence for this at this time, but various physicists are looking:
- some experimental physicists have been trying to verify Newton's gravity on very small scales, as some versions of string theory suggest that gravity might "leak out" of our universe, on small scales.
- some astronomers & cosmologists are trying to investigate the "great attractor", a region that seems to have converging galaxy clusters
- String theory suggests that there might be other universes with physical constants quite unlike ours.