Science can lift people out of poverty and cure disease. That, in turn, will reduce civil unrest.

So next time someone complains that you have made a mistake, tell him that may be a good thing. Because without imperfection, neither you nor I would exist.

The idea of 10 dimensions might sound exciting, but they would cause real problems if you forget where you parked your car.

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.

A few years ago, the city council of Monza, Italy, barred pet owners from keeping goldfish in curved bowls... saying that it is cruel to keep a fish in a bowl with curved sides because, gazing out, the fish would have a distorted view of reality. But how do we know we have the true, undistorted picture of reality?

There is a fundamental difference between religion, which is based on authority, [and] science, which is based on observation and reason. Science will win because it works.

Without imperfection, you or I would not exist.