Martin Rees is Astronomer Royal, and has been Master of Trinity College and Director of the Institute of Astronomy at Cambridge University. As a member of the UK's House of Lords and former President of the Royal Society, he is much involved in international science and issues of technological risk. His books include Our Cosmic Habitat (Princeton), Just Six Numbers, and Our Final Hour (published in the UK as Our Final Century). He lives in Cambridge, UK. Twitter @LordMartinRees