Researchers now able to stop, restart light
By William J. Cromie Gazette Staff "Two years ago we slowed it down to 38 miles an hour; now we've been able to park it then bring it back up to full speed." Lene Hau isn't talking about a used motorbike, but about light – that ethereal, life-sustaining stuff that normally travels 93 million miles from the sun in about eight minutes. Less than five years ago, the speed of light was considered one of the universe's great constants. Albert Einstein theorized that light cannot travel faster than 186,282 miles per second. Hau, 41, a professor of physics at Harvard, admits that the famous genius would "probably be stunned" at the results of her experiments. "It's nifty to look into the chamber and see a clump of ultracold atoms floating there," Hau says. She and her team continued to tweak their system until they finally brought light to a complete stop. "We didn't have much contact," she notes, "just a few e-mails." Stopping cold Hau and her group then figured out a way to make it work.