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.

I'm a traditional Jew with an orthodox background, and it informs much of my approach to science. Of course I think it's very important that if you have those sorts of backgrounds you don't impose them on other people as a clinician, of course.

We can't any longer have the conventional understanding of genetics which everybody peddles because it is increasingly obvious that epigenetics - actually things which influence the genome's function - are much more important than we realised.

I used to work for the World Health Organisation in poor countries all over the world - Bangladesh, Korea, the Philippines and India. You learn a whole range of things about how other people are living and try to connect with them to gain an understanding of where they're coming from.

I think it's important for scientists to be a bit less arrogant, a bit more humble, recognising we are capable of making mistakes and being fallacious - which is increasingly serious in a society where our work may have unpredictable consequences.

Animal rights activists talk about cruelty and torture, some backing their assertions by publishing out-of-date photographs of "experiments" banned long ago. This is a misrepresentation. The work we do is performed with compassion, care, humanity and humility. I have never seen an animal suffer pain.

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.