Not to leave planet Earth would be like castaways on a desert island not trying to escape...Sending humans to other planets ... will shape the future of the human race in ways we don't yet understand, and may determine whether we have any future at all.

A snooze button is a poor substitute for no alarm clock at all.

The progress of the human race in understanding the universe has established a small corner of order in an increasingly disordered universe.

The universe and the Laws of Physics seem to have been specifically designed for us. If any one of about 40 physical qualities had more than slightly different values, life as we know it could not exist: Either atoms would not be stable, or they wouldn't combine into molecules, or the stars wouldn't form heavier elements, or the universe would collapse before life could develop, and so on...

Real science can be far stranger than science fiction and much more satisfying.

If human life were long enough to find the ultimate theory, everything would have been solved by previous generations. Nothing would be left to be discovered.

The world has changed far more in the past 100 years than in any other century in history. The reason is not political or economic but technological-technologies that flowed directly from advances in basic science. Clearly, no scientist better represents those advances than Albert Einstein: TIME's Person of the Century.