The Incandescent Light Bulb: An Illuminating Electricity Idea - Texas

Though the light bulb itself might seem unassuming, its development in the nineteenth century was one of the most important milestones on humanity's uninterrupted path to progress. Until then, the day was structured around the sun's natural cycle; work began around sun up and ended when it was too dark to continue. People illuminated their homes with the soft, flattering light of candles and then oil lamps. In fact, one of the many legends surrounding Abraham Lincoln was that he studied particularly hard at night by the light of a candle laid on its side whose wick was lit on both sides. (That's where we get the saying: a good student "burns the candle at both ends.")

The light bulb was also a "killer app" in the development of the first American electric grid. The promise of safe, steady light encouraged public and private interests to work together to lay the groundwork that would result in electrified cities. Soon, further efforts led the charge to bring electricity to rural areas. Today, virtually every home in the United States has reliable access to the electricity that makes modern American life possible. The popular appeal and necessity of the light bulb helped to bring the dream of Edison and others to reality.

None of that could happen, however, until a stable, reasonably priced light bulb hit the market. Because of its importance (and their commercial possibilities), the light bulb was developed incrementally by several scientists in several places. As Inventors & Inventions notes, the incandescent light bulb was being designed by Joseph Swan and William Sawyer. As is often the case, the credit goes to the man (or woman) who had the biggest dreams and did the best job marketing the invention. In the case of the incandescent light bulb, of course, this is Thomas Alva Edison, dubbed the Wizard of Menlo Park, the place in New Jersey where his laboratory was located.

In the development of many significant inventions, there is a significant hurdle that must be overcome. For the incandescent light bulb, this hurdle was identifying the proper filament. It was clearly understood that running electricity through certain materials would make them glow or catch flame. The problem was that some materials would glow too brightly, making them burn out too quickly, while others would not produce enough light.

Joseph Swan had many of the right ideas. He secured a patent for a light bulb whose carbon filament was encased in a glass bulb that held a partial vacuum. This was a smart way to limit combustion of the filament, to control the rate at which it burned. As anyone who has ever set a campfire knows, a flame needs a steady supply of oxygen. Swan sealed the filament inside a partial vacuum to ensure a bright glow that wouldn't consume the material too quickly.

Edison and his lab workers tried countless kinds of materials, looking for the right balance between brightness and long life. As Edison noted in his patent, "I have carbonized and used cotton and linen thread, wood splints, papers coiled in various ways, also lamp black, plumbago, and carbon in various forms, mixed with tar and rolled out into wires of various lengths and diameters."

The standard incandescent bulb has changed only slightly in the past century and it operates in largely the same manner. The compact fluorescent lamp (or CFL), more efficient than classic bulbs, is set to become the standard in American homes. Instead of using a burning filament to produce light, a CFL bulb works in a much more interesting manner. According to ENERGY STAR, "in a CFL, an electric current is driven through a tube containing argon and a small amount of mercury vapor. This generates invisible ultraviolet light that excites a fluorescent coating (called phosphor) on the inside of the tube, which then emits visible light."

Sure, a CFL uses electricity more efficiently than an incandescent bulb, but it will take a long time for people to forget the soft, amber glow of the light bulbs we all grew up with. In fact, for over 100 years, a hand-blown 4-watt light bulb made by the Shelby Electric Company has been burning in Livermore, California, lighting the way for the town's fire department. Time will tell if CFLs will inspire the same kind of affection that the little bulb has received.