As a child, I wanted to know how things worked and to control them. With a friend, I built a number of complicated models that I could control.

If you understand the universe, you control it, in a way.

I am just a child who has never grown up. I still keep asking these 'how' and 'why' questions. Occasionally, I find an answer.

There could be shadow galaxies, shadow stars, and even shadow people.

When we understand string theory, we will know how the universe began. It won't have much effect on how we live, but it is important to understand where we come from and what we can expect to find as we explore.

For years, my early work with Roger Penrose seemed to be a disaster for science. It showed that the universe must have begun with a singularity, if Einstein's general theory of relativity is correct. That appeared to indicate that science could not predict how the universe would begin.