A hundred years ago, the electric telegraph made possible-indeed, inevitable-the United States of America. The communications satellite will make equally inevitable a United Nations of Earth; let us hope that the transition period will not be equally bloody.

Anything that is theoretically possible will be achieved in practice, no matter what the technical difficulties are, if it is desired greatly enough.

Sometimes a decision has to be made by a single individual, who has the authority to enforce it. That's why you need a captain. You can't run a ship by a committee-at least not all the time.

I'm sure the universe is full of intelligent life. It's just been too intelligent to come here.

Many, and some of the most pressing, of our terrestrial problems can be solved only by going into space. Long before it was a vanishing commodity, the wilderness as the preservation of the world was proclaimed by Thoreau. In the new wilderness of the Solar System may lie the future preservation of mankind.

It was one thing to have guessed it, another to have had that guess confirmed beyond possibility of refutation.

A man who grows that much hair,' critics were fond of saying, 'must have a lot to hide.