World Science Festival co-founder Brian Greene and Alan Alda discuss this year’s World Science Festival and the 100th anniversary of Einstein’s General Theory of Relativity. Greene will present two festival events: “Light Falls,” a retelling of the dramatic journey that resulted in one of the deepest scientific insights of all time, and “Reality Since Einstein,” about the legacy of Einstein’s theory. Alda will present "What Is Sleep?” in which audiences will watch the brain activity of a wired-up person sleeping offstage, and learn what happens during different phases, including REM sleep, when most vivid dreams occur. 

You can find a complete lineup of the 2015 World Science Festival events here.