Some 5 billion years from now, there will be a last perfect day on Earth... then the sun will begin to die, life will be extinguished, the oceans will boil and evaporate away.

What an astonishing thing a book is. It’s a flat object made from a tree with flexible parts on which are imprinted lots of funny dark squiggles. But one glance at it and you’re inside the mind of another person, maybe somebody dead for thousands of years. ... Books break the shackles of time. A book is proof that humans are capable of working magic.

Observation: I can't see a thing. Conclusion: Dinosaurs.

The universe is not required to be in perfect harmony with human ambition.

Science is a collaborative enterprise, spanning the generations. When it permits us to see the far side of some new horizon, we remember those who prepared the way - seeing for them also.

I think the discomfort that some people feel in going to the monkey cages at the zoo is a warning sign.

There is perhaps no better a demonstration of the folly of human conceits than this distant image of our tiny world.