The Earth would only have to move a few million kilometers sunward-or starward-for the delicate balance of climate to be destroyed. The Antarctic icecap would melt and flood all low-lying land; or the oceans would freeze and the whole world would be locked in eternal winter. Just a nudge in either direction would be enough.

As three laws were good enough for Newton, I have modestly decided to stop there.

There is no reason to assume that the universe has the slightest interest in intelligence—or even in life. Both may be random accidental by-products of its operations like the beautiful patterns on a butterfly's wings. The insect would fly just as well without them.

Finding intelligent life would encourage people and also of course the opportunity of learning a tremendous amount, but this is a danger. We might be so overwhelmed with knowledge and information, that we might be depressed or even become suicidal - because what's the point if they're thousands of years ahead of us? Why should we bother? - or become the ultimate couch potatoes.

Until we get rid of religion, we won't be able to conduct the search for God.

Death focuses the mind on the things that really matter: why are we here, and what should we do?

Few artists thrive in solitude and nothing is more stimulating than the conflict of minds with similar interests.