There are many of us thinking of one version of parallel universe theory or another. If it's all a lot of nonsense, then it's a lot of wasted effort going into this far-out idea. But if this idea is correct, it is a fantastic upheaval in our understanding.

We do not know whether there are extra dimensions or multiverse. Let's go forward with the possible ideas that come out of the mathematics. It's hard for us to imagine a universe that would have no time at all.

In essence, we string theorists have been trying to work out the score of the universe, the harmonies of the universe, the mathematical vibrations that the strings would play. So musical metaphors have been with us in science since the beginning.

Science is the process that takes us from confusion to understanding.

The revelation we've come to is that we can trust our memories of a past with lower, not higher, entropy only if the big bang - the process, event, or happening that brought the universe into existence - started off the universe in an extraordinarily special, highly ordered state of low entropy.

Sometimes attaining the deepest familiarity with a question is our best substitute for actually having the answer.

I'd say many features of string theory don't mesh with what we observe in everyday life.