A model is such a fascinating toy that you fall in love with your creation.

We do not know how much of the environmental change is due to human activities and how much [is due] to long-term natural processes over which we have no control.

For a physicist mathematics is not just a tool by means of which phenomena can be calculated, it is the main source of concepts and principles by means of which new theories can be created.

Aviation is the branch of engineering that is least forgiving of mistakes.

I don't know, but I think it's quite possible that the more science you teach kids in school the more it turns them off, so I don't know. I mean you never can tell which way it will go.

Do not imagine that you have to know everything before you can do anything. My own best work was done when I was most ignorant.

I think that the artificial-intelligence people are making a lot of noise recently, claiming that artificial intelligence is making huge progress and we're going to be outstripped by the machines.