The Ph.D. system was designed for a job in academics. And it works really well if you really want to be an academic, and the system actually works quite well. So for people who have the gift and like to go spend their lives as scholars, it's fine. But the trouble is that it's become a kind of a meal ticket - you can't get a job if you don't have a Ph.D.

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

I think it's a big mistake to decide too soon what you're going to do with your life.

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

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.

Plasma seems to have the kinds of properties one would like for life. It's somewhat like liquid water--unpredictable and thus able to behave in an enormously complex fashion. It could probably carry as much information as DNA does. It has at least the potential for organizing itself in interesting ways.

There are two different ways of looking at the universe; and it's the same universe with two different windows. The science window gives you a view of the world, and the religion window gives you a totally different view. You can't look at both of them at the same time, but they're both true.