Visiting a parallel universe

So far, I have only discussed intra-universe wormholes which
would connect two distant points in our own universe. But
Wheeler’s quantum wormholes might also connect us with a
parallel universe. These are referred to by Hawking as baby
universes since they would be like bubbles which form and grow
out of the quantum foam in our Universe and connect to ours via
a wormhole like an umbilical cord. Such a baby universe might
itself then start to expand within higher dimensional hyperspace
and, if the wormhole connection is broken, be forever separated
from ours. In fact, if this is true then our own universe might itself
have popped out of the quantum foam of yet an earlier universe.
Thus, in the same way that we would inflate an intra-universe
wormhole up from the quantum level, we can also think of inflating such an inter-universe wormhole that connects us with
a neighbouring universe. If it turns out that we live in a closed
universe, then one can imagine a distant future in which the
Universe is collapsing towards a Big Crunch. If humans are still
around at that time they will want to be able to escape the crush
of the final singularity by jumping through a wormhole into a
younger universe which had the same properties as our own.