Hawking: alternative versions of history occur

The Independent of London carries Stephen Hawking's speech in Spain on alternative views of history occurring in the universe. I found it fascinating, but in an another plane of history I probably skipped it to hang out at the beach:

What does it mean to say that the universe has many alternative histories? Which is the real history of the universe? To answer such profound philosophical questions, I think one must adopt the positivist approach of Karl Popper and others. in this, a theory is just a mathematical model to describe the observations. It has no claim to reality, whatever that may be. Two very different models may describe the same observations. Both theories are equally valid, and neither can be said to be more real than the other. The results are disappointing for those who hoped that the ultimate theory would predict everyday physics. We live in the anthropically allowed region in which life is possible, but I think we might have chosen a better location.

Even someone as smart as the Lucasian Professor of Mathematics at Cambridge University finds the universe mysterious.