In science it is not enough to think of an important problem on which to work. It is also necessary to know the means which could be used to investigate the problem.

I'm all in favor of the democratic principle that one idiot is as good as one genius, but I draw the line when someone takes the next step and concludes that two idiots are better than one genius.

Don't lie if you don't have to.

We turned the switch, saw the flashes, watched for ten minutes, then switched everything off and went home. That night I knew the world was headed for sorrow.

A great power imposes the obligation of exercising restraint, and we did not live up to this obligation. I think this affected many of the scientists in a subtle sense, and it diminished their desire to continue to work on the bomb.

I am thinking of keeping a diary, not with the intend to publish it, merely to record the facts for the information of God, in case God does not know my version of the facts.

If the thickness is larger than the critical value I can produce an explosion.