Death of the Universe

The death of the universe could rival its birth in explosive drama if a puzzling form of energy continues to accelerate the expansion of space-time. Since the 1920s astronomers have thought the expansion was slowing down, but recent observations of distant stars reveal that the stretching of space is actually speeding up. If it picks up even more, the universe could be headed for a "big rip." An artist's conception of this scenario—one of many possible fates—shows how, some 20 billion years from now, unchecked expansion could tear matter apart, from galaxies all the way down to atoms.