Making a Better Light Bulb

April 29, 2009
Making a Better Light Bulb
How many engineers does it take to make a better light bulb? We’ll find out today on Engineering Works.

The round incandescent light bulb we all know hasn’t changed much since Thomas Edison invented it 125 years ago. Thin wires, called filaments, inside the glass bulb glow when electricity zips through them. That glow gives us light to see by. But there’s a hitch. Only about a tenth of that energy gives us light. The rest just heats the bulb so we can burn our fingers. Ouch!

Fluorescent lights -- those long tubes that light offices and other commercial spaces -- appeared in 1938. Instead of filaments, fluorescent tubes are filled with a gas that glows when electricity passes through it. They’re lots more efficient.

Fluorescent lights are cool. Really. They don’t get hot, and they need just one-fourth the energy incandescent bulbs need to produce the same amount of light. And fluorescent bulbs last 10 times longer than incandescent ones. They had problems, though. They didn’t fit a lot of places regular light bulbs did. And they hummed.

Then, compact fluorescent lamps entered the picture in the 1980s. They solved a lot of the problems regular fluorescents had: they screw into regular light sockets; they’re small enough to fit most places a conventional bulb will fit; they don’t hum; and they’re as stingy with the energy they use as regular fluorescent bulbs.

Guess it’s time to turn out the lights for today.