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.

You ask: what is the meaning or purpose of life? I can only answer with another question: do you think we are wise enough to read God's mind?

The greatest unsolved mysteries are the mysteries of our existence as conscious beings in a small corner of a vast universe.

If you want to have a program for moving out into the universe, you have to think in centuries not in decades.

A good scientist is a person with original ideas. A good engineer is a person who makes a design that works with as few original ideas as possible. There are no prima donnas in engineering.

Technology must be guided and driven by ethics if it is to do more than provide new toys for the rich.

The idea that global warming is the most important problem facing the world is total nonsense and is doing a lot of harm.

Unfortunately the global warming hysteria, as I see it, is driven by politics more than by science.

In the end it is how you fight, as much as why you fight, that makes your cause good or bad.

So long as you have courage and a sense of humor, it is never too late to start life afresh.

Technology is a gift of God. After the gift of life it is perhaps the greatest of God's gifts. It is the mother of civilizations, of arts and of sciences.

Diamonds are formed in pressure

Earning happiness means doing good and working, not speculating and being lazy. Laziness may look inviting, but only work gives you true satisfaction.

Stop putting off today madam

Аs I've mentioned many times, sitting through graduation ceremonies is one of life's drearier milestones.

I like to think that each book I start is a completely new departure But I’ve learned that whatever you do, readers will have no difficulty assimilating it into what you’ve done before.

"You are fairly smart," I said after a while. "You are fairly good at compliments," he answered.

A lot of scientists act on their beliefs and so do things that look crazy to the rest of us.

My daughter loves horses. My other daughter loves soccer.

It’s hard to look in charge when you’re hunched over like Quasimodo.

I'm imperfect. There are things in time that will bother me, but I don't dwell on them. It's another thing to dwell on it your whole day and let it bother you.