Most of the intelligence out there must be artificial intelligence. We keep looking for critters like us living on a planet like ours, where in fact the majority of the intelligence out there is not biological. That would be my argument.

In archaeology, context is the basis of many discoveries that are imputed to the deliberate workings of intelligence. If I find a rock chipped in such a way as to give it a sharp edge, and the discovery is made in a cave, I am seduced into ascribing this to tool use by distant, fetid and furry ancestors.

Our brains are continuing to evolve, and perhaps a few tens of thousands of years from now, our descendants will walk around with five pound brains, allowing them insights that we can't imagine.

While it may be disappointing, I have to confess to people who ask for my insights on the meaning of it all that astronomy doesn't provide any clearly useful data on matters of sin and souls.

We must get beyond textbooks, go out into the bypaths... and tell the world the glories of our journey.

For a long time, our only mode of travel was an Econoline van. Eleven of us, with nine sleeping in the back on two mattresses.

It is in the compelling zest of high adventure and of victory, and in creative action, that man finds his supreme joys.

Death by plane crash scares me. I travel a lot, and when you hit turbulence, and post 9/11, that's in the back of my mind a bit.