Physicists demonstrate first time reversal of water waves
Thursday, August 23, 2012 - 14:30
in Physics & Chemistry
(Phys.org)—In spite of its name, the time reversal of a wave doesn't involve sending the wave back in time, but for scientists, the process is almost as compelling. After a source generates a wave, the wave propagates through a medium and is recorded at a few points in its surroundings by an optical method. Then, the wave is re-emitted in a way so that its energy focuses back at the initial source position, as though the wave were being played backwards. Because the wave precisely retraces its original path as it travels back to its source, its mathematical description is reversed in time but is otherwise exactly the same.