Really exotic methods of propulsion . . . will have to be devised to get there. How it will be done, I do not know. Whether it will be done, I am not quite certain. But I would bet it can be done.

Society's emissions of carbon dioxide may or may not turn out to have something significant to do with global warming-the jury is still out.

If not for me, the H-bomb would have been developed in Russia first. In the U.S., we'd now be speaking Russian.

There's no system foolproof enough to defeat a sufficiently great fool.

When Columbus took off, the purpose was to improve trade relations with China. That problem has not been solved to this very day, but just look at the by-products.

Knowing he [Bob Serber] was going to the [first atom bomb] test, I asked him how he planned to deal with the danger of rattlesnakes. He said, 'I'll take along a bottle of whiskey.' … I ended by asking, 'What would you do about those possibilities [of what unknown phenomena might cause a nuclear explosion to propagate in the atmosphere]?' Bob replied, 'Take a second bottle of whiskey.'

Physics without mathematics is meaningless.