The Sound Laser

Lasers have become ubiquitous: they read the prices of our groceries, play our compact discs, and even clean our clogged arteries. Now, thanks to a group of French physicists, the world has its first saser- -a device that amplifies sound the way lasers amplify light. The saser isn’t of much use yet, but one day the researchers hope to turn it into the world’s most sensitive listening device.