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. Wind Power Without the Blades: Big Pics.