Literary agent John Brockman challenged the array of scientists that he hosts on his website by asking: What is the most important invention of the past two thousand years?. This book provides a showcase for more than a hundred of their responses, which are as varied as the participants themselves. Gutenberg's printing press wins the most endorsements, but the neuroscientist Colin Blakemore argues for the birth-control pill, biologist Richard Dawkins nominates the spectroscope and physicist Freeman Dyson makes a case for hay! An eclectic collection of ideas from some of the foremost thinkers of our age.