Researchers use super-cool goo to dramatically slow speed of light

This part of the maze houses an 'optical molasses' substance discovered a few years ago RELATED VIDEO CNN's Bill Delaney reports on the breakthrough from Cambridge, Massachusetts Windows Media 28K 80K

February 19, 1999
Web posted at: 8:13 p.m. EST (0113 GMT)

BOSTON (CNN) -- The time-honored phrase "faster than the speed of light" might have to be reworked, thanks to the work of a Danish physicist.

By shooting a laser beam of light through a super-cooled glob of a kind of optical molasses, Lene Vestergaard Hau and her team at the Rowland Institute for Science in Cambridge, Massachusetts, were able to slow the speed of light down to just 38 miles per hour -- not even fast enough for the slow lane of a freeway.

By contrast, the normal speed of light in a vacuum is about 186,000 miles per second -- 20 million times as fast.

"I would probably not call it God-like, but I would probably say ... we are tampering with nature in a very peculiar, very bizarre way," Hau says.

Hau points to an intricate maze of mirrors, part of the slowing process

The research, conducted at the Rowland Institute and Harvard University, was reported in Thursday's issue of the journal Nature.

The substance that slows the light, called Bose-Einstein condensate, is a microscopic glob of atoms slowed to almost absolute zero -- 459.67 degrees below zero Fahrenheit, the lowest temperature theoretically possible.

Researchers believe that it may be possible to slow the speed of light even further, by a factor of 1,000.

"A human could move faster than that" says Stanford University's Steve Harris, who participated in the project. "But a human couldn't move through a Bose-Einstein condensate, I'll tell you that."

Researchers believe learning how to slow light could eventually have a number of practical applications -- improving computers and communications devices, making television displays and laser light shows more vivid and creating better night-vision goggles.

Correspondent Bill Delaney and The Associated Press contributed to this report.

Note: Pages will open in a new browser window

External sites are not endorsed by CNN Interactive.