Nowadays if you're dependent on a grant - and 99% of them are - you can't make mistakes as you won't get another one if you do.

The apologists for space science always seem over-impressed by engineering trivia and make far too much of non-stick frying pans and perfect ball-bearings. To my mind, the outstanding spin-off from space research is not new technology. The real bonus has been that for the first time in human history we have had a chance to look at the Earth from space, and the information gained from seeing from the outside our azure-green planet in all its global beauty has given rise to a whole new set of questions and answers.

Humans are too stupid to prevent climate change from radically impacting on our lives over the coming decades.

Florida will be gone altogether, the whole damned place, in not too long.

This programme to stop nuclear by 2020 is just crazy. If there were a nuclear war, and humanity were wiped out, the Earth would breathe a sigh of relief.

One thing that being a scientist has taught me is that you can never be certain about anything. You never know the truth. You can only approach it and hope to get a bit nearer to it each time. You iterate towards the truth. You don't know it.

The big threat to the planet is people: there are too many, doing too well economically and burning too much oil.