The remarkable position in which we find ourselves is that we don't actually know what we actually know.

The human diet consists of just nine plants: corn, rice, wheat, potatoes, cassava, sorghum, millet, beans, barley, rye and oats.

Because we humans are big and clever enough to produce and utilize antibiotics and disinfectants, it is easy to convince ourselves that we have banished bacteria to the fringes of existence. Don't you believe it. Bacteria may not build cities or have interesting social lives, but they will be here when the Sun explodes. This is their planet, and we are on it only because they allow us to be.

In three minutes, 98 percent of all the matter there is or will ever be has been produced. We have a universe

It is a slightly arresting notion that if you were to pick yourself apart with tweezers, one atom at a time, you would produce a mound of fine atomic dust, none of which had ever been alive but all of which had once been you.

America is a great disappointment to me. As I said in one of my books, other societies create civilisations; we build shopping malls.

When you tell an Iowan a joke, you can see a kind of race going on between his brain and his expression.