Which Technological Invention Changed the World?

Scientists like Jared Diamond argue that human history is essentially the story of technology. Our technological advancements are what propelled us from caves to cities, from gaslight to nuclear reactors, and from horseback to orbit. But with each advance comes a potential dark side: deadlier warfare, toxic pollution,… » 7/21/08 1:04pm 7/21/08 1:04pm