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Goethe said, "Someday perhaps the inner light will shine forth from us, and then we'll need no other light."

The brilliant German polymath's beer stein probably was half-full when he made that observation, but that day, regretfully, is no where in sight, not even in the imagination of a Faustian deal. So we'll still need to rely on natural light and the light that we create.

In 1802 Sir Humphry Davy created the first incandescent light by passing current through a thin strip of platinum. It was not, however, bright enough nor did it last long enough to be practical, but it was the first in a long line of efforts that ended with Thomas Edison's creation of the first practical incandescent lamp 77 years later. Since then we've seen fluorescent bulbs, neon bulbs and others. The latest rage is the light-emitting diode. LEDs are making inroads both indoors and outdoors, where, instead of just overpowering ambient light, it actually recycles it.

One spur is the European directive to eliminate hazardous substances, which pushes CCFLs out of the picture because of mercury content. Most experts agree that LEDs are the next best solution.

Other reasons? There is no exposure to voltage with LEDs. CCFLs strike at the start can exceed 1,200 volts AC and typically 600-800 AC run voltage. LEDs can drop to benign voltage of 20 volts DC. They eliminate arc-over conditions, which is important for medical applications where they have to be concerned with arcing or leakage that could harm the caregiver or patient. LEDs have perfected switching time at 100 nanoseconds, compared to 5 milliseconds for CCFLs.