That's one of those meaningless and unanswerable questions the mind keeps returning to endlessly, like the tongue exploring a broken tooth.

Good morning, Dr. Chandra. This is Hal. I am ready for my first lesson.

In the long run, there are no secrets. in science. The universe will not cooperate in a cover-up.

Death focuses the mind on the things that really matter: why are we here, and what should we do?

The moment when one first meets a great work of art has an impact that can never again be recaptured.

Mars is the next frontier, what the Wild West was, what America was 500 years ago. It's time to strike out anew....Mars is where the action is for the next thousand years....The characteristic of human nature, and perhaps our simian branch of the family, is curiosity and exploration. When we stop doing that, we won't be humans anymore. I've seen far more in my lifetime than I ever dreamed. Many of our problems on Earth can only be solved by space technology....The next step is in space. It's inevitable.

New ideas pass through three periods: 1) It can't be done. 2) It probably can be done, but it's not worth doing. 3) I knew it was a good idea all along!