The nightly news and conventional wisdom tell us that things are bad and getting worse. Yet despite dire predictions, scientists see many good things on the horizon. John Brockman, publisher of Edge (www.edge.org), the influential online salon, recently asked more than 150 high-powered scientific thinkers to answer a vital question for our frequently pessimistic times: "What are you optimistic about?" Spanning a wide range of topics-from string theory to education, from population growth to medicine, and even from global warming to the end of world-What Are You Optimistic About? is an impressive array of what world-class minds (including Nobel Laureates, Pulitzer Prize winners, New York Times bestselling authors, and Harvard professors, among others) have weighed in to offer carefully considered optimistic visions of tomorrow. Their provocative and controversial ideas may rouse skepticism, but they might possibly change our perceptions of humanity's future.