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.

There are grounds for cautious optimism that we may now be near the end ofthe search for the ultimate laws of nature.

In real time, the universe has a beginning and an end at singularities that form a boundary to space-time and at which the laws of science break down.

One cannot really argue with a mathematical theorem.

There are too many accidents that can befall life on a single planet.

It is all right to make mistakes; nothing is perfect because with perfection, we would not exist.

I think the next century will be the century of complexity.