Carbon dioxide is unusual because it doesn't go through the usual three phases of matter, from solid to liquid to gas, but it goes straight from solid to gas. The volume of the gas is much greater than the volume of the solid. When a solid turns into a gas, we say it sublimes. The process is sublimation.

While nobody has identified any gene for religion, there are certainly some candidate genes that may influence human personality and confer a tendency to religious feelings. Some of the genes likely to be involved are those which control levels of different chemicals called neurotransmitters in the brain.

People think I appear on television to promote my image. That's not fair. I hate filming. I turned down 'Strictly Come Dancing.' But television is a wonderful opportunity to promote scientific ideas. 'Super Doctors' is a very thoughtful piece.

When I grew up, we didn't have a TV, and I think more families today have ambitions of getting out of their environment, such as sending their children to university.

Although religion might be useful in developing a solid moral framework - and enforcing it - we can quite easily develop moral intuitions without relying on religion.

I did not study science at school until I was 13, when I was totally turned on by a seemingly dreary old teacher who suddenly, unannounced, manufactured a huge explosion in the middle of a totally boring monologue. From then on, all of his class wanted to make explosions.

It's extraordinary to think that if you walked into a room and said you had never heard of Hamlet, you would be regarded as a Philistine. But you could walk into the same room and say, 'I don't know what a proton is,' and people would just laugh and say, 'Why should you know?'