The prediction I can make with the highest confidence is that the most amazing discoveries will be the ones we are not today wise enough to foresee.

If you wish to make an apple pie from scratch, you must first invent the universe.

Ask courageous questions. Do not be satisfied with superficial answers.

Accommodation to change, the thoughtful pursuit of alternative futures are keys to the survival of civilization and perhaps of the human species.

The significance of our lives and our fragile planet is then determined only by our own wisdom and courage. We are the custodians of life's meaning. We long for a Parent to care for us, to forgive us our errors, to save us from our childish mistakes. But knowledge is preferable to ignorance. Better by far to embrace the hard truth than a reassuring fable. If we crave some cosmic purpose, then let us find ourselves a worthy goal.

This oak tree and me, we're made of the same stuff.

There are many hypotheses in science which are wrong. That’s perfectly all right: it’s the aperture to finding out what’s right. Science is a self-correcting process.