Researchers look into advantages of the light-emitting diode

• "We are looking at lighting systems that provide more than lighting," he says.
• Most people know them as being quite small, like the lights that form numbers on digital clocks or blink on answering machines.
• But recent technological advances have made them much more powerful, able to illuminate swimming pools and serve as traffic signals, for example.
• LEDs offer energy savings when compared to standard lighting, but Schubert is more excited about some other properties.
• And that, Schubert says, opens the door to using lights for electronic communication as well as illumination.
• * brake lights that tell a closely following car to stop, even if the driver doesn't notice.
• * room lights that transmit messages to devices worn by only certain people, like particular doctors or nurses in a hospital, rather than speakers that spew announcements for everybody to hear.
• "I think we're looking at maybe a time frame of the next five to 20 years," he said.
• Meanwhile, his Rensselaer colleague Mariana Figueiro believes that lighting in offices and schools could be improved to help people stay healthy and productive, by acting on their internal body clocks.
• "Light isn't just for vision any more," says Figueiro, program director at Rensselaer's Lighting Research Center and head of a committee on light and human health for the Illuminating Engineering Society of North America.
• The 24-hour internal body clock is best known for governing cycles of alertness and sleep, and for producing jet lag when people travel across time zones.
• "We're pretty much blue-sky detectors" whose clocks count on bright days and dark nights, said Figueiro.
• To counter that, architects and lighting engineers might someday take body clocks into account when they design lighting schemes, she said.