Paul Davies

Astonishingly, in spite of decades of research, there is no agreed theory of cancer, no explanation for why, inside almost all healthy cells, there lurks a highly efficient cancer subroutine that can be activated by a variety of agents - radiation, chemicals, inflammation and infection.

A permanent base on Mars would have a number of advantages beyond being a bonanza for planetary science and geology. If, as some evidence suggests, exotic micro-organisms have arisen independently of terrestrial life, studying them could revolutionise biology, medicine and biotechnology.

I don't think of people as black or white. It's a question of are they photogenic or not? I don't think anyone says, 'Let's book her. She's black.' I think they say, 'Let's book her. She's good.' We've come that far.