This is a little book of profound questions (only questions!)—unknowns that address the secrets of our world, our civilization, the meaning of life. Here are the deepest riddles that have fascinated, obsessed, and haunted the greatest thinkers of our time, including Nobel laureates, cosmologists, philosophers, economists, prize-winning novelists, religious scholars, and more than 250 leading scientists, artists, and theorists. In The Last Unknowns, John Brockman, publisher of Edge.org, asks "a mind-blowing gathering of innovative thinkers" (Booklist): "What is ‘The Last Question,’ your last question, the question for which you will be remembered?"