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.

Short stories are my favorite art form. A good one is compact and complete, a telling little slice of life, capturing a moment in time that - for the character - defines her, changes her, is the tipping point for all that will follow.

The popular mythology of creative genius depends on beloved stereotypes of the artist in youth and old age: the misunderstood upstart who forces us to see the world afresh; and the revered sage who shows us depths of insight attainable only through a lifetime of hard-won experience.