Transforming a fluorescent glare into a guiding light

A professor at the Massachusetts Institute of Technology has figured out a way to transform fluorescent tube fixtures in the ceilings of airports, museums, offices and factories into inexpensive data transmitters.

Pass under one of these revamped fluorescent lights and it may send out a message that flashes on your handheld computer screen saying: "Turn left at the next corridor for Gate A. There is a cash machine just as you reach the intersection."

To create fluorescent tubes that can communicate, Dr Steven Leeb, has modified ordinary fluorescent fixtures so that they beam data as well as illumination. Dr Leeb, who teaches circuit design and other subjects at MIT, does this by changing one component in the fixture to produce fluctuations in the light that can be read as a digital signal.

These fluctuations, imperceptible to the eye, are easily detected by light sensors that pick up the signals and pass them to processors and software that produce voice, music or text messages. The lights may be linked to create inexpensive data networks.