Suppose that we are wise enough to learn and know - and yet not wise enough to control our learning and knowledge, so that we use it to destroy ourselves? Even if that is so, knowledge remains better than ignorance. It is better to know - even if the knowledge endures only for the moment that comes before destruction - than to gain eternal life at the price of a dull and swinish lack of comprehension of a universe that swirls unseen before us in all its wonder. That was the choice of Achilles, and it is mine, too.

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.

Radiation, unlike smoking, drinking, and overeating, gives no pleasure, so the possible victims object.

Of course there are worlds. Millions of them! Every star you see has worlds, and most of those you don't see.

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.

There is an art to science, and a science in art; the two are not enemies, but different aspects of the whole.

There is as yet insufficient data for a meaningful answer.