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.

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.

Childhood depression tends to be more common in inner cities, being most frequently related to serious social deprivation, bullying, domestic violence, wartime experience and famine. It is, for example, a serious problem among children who are traumatised refugees.

It is important that legislation keeps pace with scientific progress.

That Britain today is a liberal society is largely because of the philosophy and outlook of the Anglican Church, which did so much to shape our core values in the past few centuries.

I don't much like being a public figure, because so often how people appear is not how they really are, and I think one of the issues about our society is that we make judgments about people on the basis of very flimsy evidence.

Surgeons always underestimate the pain and disability involved in what they do to people.