Physicist who slowed the speed of light to speak

Lene Vestergaard Hau, a Danish physicist who stunned the global scientific community by slowing the speed of light in a Harvard University research laboratory, will discuss her work at 8 p.m. Thursday, Jan. 13, in Room 204, Carnegie Science, Bates College. The public is invited to attend without charge.

Light normally travels through a vacuum at about 186,000 miles per second. Hau and her team of physicists at Harvard’s Rowland Institute for Science slowed the speed of light to 38 miles per hour by shooting a laser through an extremely cold gas of sodium atoms, as reported in the February 1999 issue of Nature.

“We have really created an optical medium with crazy, bizarre properties,” said Hau of the Bose-Einstein condensate, the sodium gas cooled to nearly 459.67 degrees Fahrenheit below zero. “It works like optical molasses to slow the light.”

If the space between the sun and the Earth were composed of the Bose Einstein condensate, it would take a ray of sunlight 300 years to reach Earth rather than a little more than eight minutes, according to Hau.

While slow-speed light is now confined to the realm of laboratory research, Hau believes future practical applications include improved communications technology, television displays and night-vision devices.