ENCORE Ever since Einstein, we've known that time doesn't barrel willy-nilly into the future. Moving clocks tick at a different rates, and by riding a fast rocket, we can slow time to a crawl. Such tricks may give you a way to see the distant future, but can you go back in time?
Discover one man's quest to build a time machine. Also learn how to put the brakes on aging by getting near a black hole.
Plus, does your entire life really pass before your eyes if you jump off the Brooklyn Bridge? Our perception of time.