Physicists Learn to Turn Back Time

According to the Second Law of Thermodynamics, any isolated system tends to grow more disorderly over time—the fundamental reason the mess in your sink only gets worse if you don't wash the dishes. But Denis Evans, a physicist at the Australian National University, has found that the second law can sometimes be forced to run backward. To physicists, this is a discovery equivalent to finding that the dishes washed themselves while you waited. Evans and his colleagues searched for flaws in the second law by adding fine latex beads, each less than a millionth of an inch wide, to a water-filled cell big enough to fit on a microscopic stage. The researchers shook the cell in a precise rhythm and used a laser beam to track the progress of a single bead within the chamber. They found that when they observed the bead for periods of no more than a ...