All of a sudden, space isn't friendly. All of a sudden, it's a place where people can die. . . . Many more people are going to die. But we can't explore space if the requirement is that there be no casualties; we can't do anything if the requirement is that there be no casualties.

Saying something is 'too bad' is easy. You say you disapprove, which makes you a nice person, and then you can go about your business and not be interested anymore. It's a lot worse than 'too bad.' It's against everything decent and natural.

Working ten hour days allows you to fall behind twice as fast as you could working five hour days.

I don't expect to live forever, nor do I repine over that, but I am weak enough to want to be remembered forever. - Yet how few of those who have lived, even of those who have accomplished far more than I have, linger on in world memory for even a single century after death

Do not forget that a traitor within our ranks, known to us, can do more harm to the enemy than a loyal man can do good to us.

I figure that if God actually does exist, he is big enough to understand an honest difference of opinion.

The fundamentalists deny that evolution has taken place; they deny that the earth and the universe as a whole are more than a few thousand years old, and so on. There is ample scientific evidence that the fundamentalists are wrong in these matters, and that their notions of cosmogony have about as much basis in fact as the Tooth Fairy has.