Physicist, Institute for Advanced Study; author of Disturbing The Universe; From Eros To Gaia.

"The best questions were asked long ago. For example, Fermi's question, 'Where are they?', and Blake's question, 'How do you know but ev'ry bird that cuts the airy way is an immense world of delight, clos'd by your senses five?' My question is, 'What goes on inside the head of a baby?' "