Why light-emitting diodes are replacing light bulbs

If a time traveler from a hundred years ago were to visit a hometoday, much of the technology would be completely alien. Thetelevision, cordless phone and computer would probably leave himflabbergasted.

But on seeing a light bulb, he might say, "Ah! Here's something Irecognize. A few of those grace my home, too."

If the visitor returned in 15 years, Thomas Edison's bright ideamight be missing. The likely replacement: light-emitting diodes, orLEDs.

LED lamps were unthinkable until the technology cleared a majorhurdle just a dozen years ago. Since then, LEDs have evolved quickly,and are being adapted for many uses, including pool illumination andreading …