The uncertainty relation does not refer to the past; if the velocity of the electron is at first known and the position then exactly measured, the position for times previous to the measurement may be calculated.

If the lecture is good, then everything is too smooth. That's the same in music: if the performance is too good, you really don't enjoy it, because it just goes by, and you can never penetrate into the heart of it. Sometimes a poor performance is better for enjoyment, because you can look at those things that were wrong and analyze them.

This proving of such and such I found to be almost like cheating. You start somewhere, and then you go into a dark tunnel, and then you come out at another place. You find that you have proved what you wanted to prove, but in the tunnel, you don't see anything.

There is a great difference between discoveries and inventions. With discoveries, one can always be skeptical, and many surprises can take place. In the case of inventions, surprises can really only occur for people who have not had anything to do with it.

Don't tell me peace has broken out.

I follow the teachings of Major General Smedley Darlington Butler, United States Marine Corps. He won two Congressional Medals of Honor, and he wrote the highly controversial antiwar book 'War is a Racket.'

If what I've been told is true - and I believe it is, General David Petraeus, a commander with soldiers deployed in two theaters of war, has had multiple meetings with Dick Cheney, the former vice-president of the United States, to discuss Petraeus's candidacy for the Republican nomination for the presidency.

In our quest for peace, we should constantly ask ourselves what we should do to create conditions in which peace can prosper.