The best proof that there's intelligent life in the universe is that it hasn't come here.

No utopia can ever give satisfaction to everyone, all the time. As their material conditions improve, men raise their sights and become discontented with power and possessions that once would have seemed beyond their wildest dreams. And even when the external world has granted all it can, there still remain the searchings of the mind and the longings of the heart.

If children have interests, then education happens.

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.

All explorers are seeking something they have lost. It is seldom that they find it, and more seldom still that the attainment brings them greater happiness than the quest.

Astronomy, as nothing else can do, teaches men humility.

The one fact about the future of which we can be certain is that it will be utterly fantastic.