Shedding Light on the History of the Light Bulb and Its Bright Future
Reading by candlelight may seem romantic, but it's tough on the eyes, and an errant breeze leaves everyone in the dark. Imagine having to light up an oil-soaked torch for a little extra, portable light outside. Thank goodness we have the light bulb, and thank goodness we've been getting better at making it. From glowing strips of charcoal to light emitting diodes (LEDs), we've come a long way.
First Light: The Dim Beginning
It was a dark and stormy--well, it was certainly a dark night, but that would soon change. The year was 1809, and an English scientist by the name of Humphry Davy was about to make the world a brighter place. He had come up with a rudimentary battery to which he attached some wires. In between these wires he affixed two pieces of charcoal, which--we can only assume--surprised him when they began to glow. Thus the light bulb was conceived, or at least electric arc, the phenomenon that made the charcoal glow for Davy, was discovered.
It wasn't until 1820 that Warren De la Rue attempted to produce the first incandescent light bulb. Enclosing a platinum coil inside of an evacuated tube, he ran a current through and there was light. The longevity had improved greatly from Davy's carbon strips, but the cost of platinum was prohibitive.
Success! A Little More Light on the Subject
With so many scientists around the globe working to produce a practical light bulb, it was only a matter of time before somebody got it right. In 1879, this happened--twice. Thomas Alva Edison and Wilson Swan had independent breakthroughs. Both designs were based on a carbon fiber filament, which was derived from cotton. Though a huge step in the right direction, this bulb lasted a scant 13.5 hours. Edison redoubled his efforts to create a longer-lasting light, and only one year later, he developed a bamboo-derived filament that could last for over one thousand hours.
More developments came, though years later. Karl Auer used an osmium filament in 1898. In 1903, Siemens and Halske, a German engineering team, used tantalum. Both theirs and Auer's developments improved light bulb burn time.
1906 through 1910 saw the development of ductile tungsten and then its use in a light bulb. Thanks to the efforts of William Coolidge and the General Electric Company, this became the practical, long burning solution that would light our way for most of the twentieth century. Some improvements were made to prevent the tungsten from burning up and coating the inside of bulb with soot. The gases that were added to stop the soot, argon and nitrogen, were also found to carry heat away from the filament, making it last even longer.
Seeing Things in a Different Light
When all of this excited about incandescent lighting was going around, circa 1857, a French physicist by the name of Alexandre E. Becquerel was putting his time into fluorescence and phosphorescence. He experimented with various tubes and coatings, but never quite had success.
A German physicist, Julius Plucker, and a glassblower, Heinrich Geissler, got together in the mid 1800s to further Becquerel's work. They found that passing a current through a glass tube containing tiny amounts of a gas made light. Much like the French forerunner, they did not have much success. There were, of course, many others attempting to produce practical vapor lamps, but they too failed.
Without all of their work, though, Peter Cooper Hewitt wouldn't have been able to produce the world's first mercury vapor lamp in 1901. This lamp was the predecessor to the fluorescent lights we have today, which use electricity to excite mercury vapor, creating luminescence.
Beginning to See the Light: A Brighter Future Emerges
Electroluminescence, discovered by Englishman Henry J. Round in 1907, doesn't just sound cool; it's the guiding principle behind light emitting diodes (LEDs). The first LED was created independently of Henry J. Round by a Russian scientist named Oleg Vladimirovich Losev in the mid 1920s. No practical use came about for decades, though.
In 1955, Rubin Braunstein observed that simple diodes using gallium antimonide (GaSb), gallium arsenide (GaAs), indium phosphide (InP), and silicon-germanium (SiGe) all produced infrared light. It was in 1961 that the first infrared LED was patented by Bob Biard and Gary Pittman; it used GaAs.
All of this intensely scientific research culminated in the 1962 with Nick Holonyak Jr. inventing the first visible-spectrum LED. He earned the title, Father of the Light-Emitting Diode, for this one. It wasn't until 1976 that a high-brightness, high-efficiency LED was invented by T.P. Pearsall. Despite the prohibitive price at the time, Hewlett Packard used red LEDs in their early handheld calculators' alphanumeric displays.
Since the birth of practical LEDs in the 1960s, their efficiency and light output have increased exponentially, doubling about every 36 months. Organic LEDs (OLEDs) are now being used to make the thinnest, highest-definition displays ever created, and they are only one of the many LED innovations.
LEDs Light the Way
LED light bulbs have become extremely efficient, now boasting an 80 to 90 percent power savings over the archaic-seeming incandescent bulb, while producing similar brightness. Not only that, but LED light bulbs can last longer than 100,000 hours, which is more than eleven and a half years of constant burn.
Their versatility is staggering. Used by hikers in ultra-light, ultra-bright headlamps; car manufacturers as stylish, highly functional lights; and engineers in state-of-art fiber-optic technology, these little light bulbs can do pretty much anything. They can even replace nearly every other light bulb already in use, from your home to your local stadium.
Another advantage, LED lights are environmentally friendly and not just for their power sipping ways. The push towards compact fluorescent bulbs has put mercury in homes across the nation. LED light bulbs last longer, light instantly, run silently, replace a wider array of other bulbs (including halogen lamps), are more durable because of their solid-state design, and don't contain toxic elements.
The next time a light goes out in your home, consider replacing it with an LED light bulb. It could be your brightest idea yet.
Sources
About.com, The History of Fluorescent Lights
Enchanted Learning, The Invention of the Light Bulb: Davy, Swan and Edison
IN-VSEE, The History of the Light Bulb
Nanophotonics, The Life and Times of the LED--a 100-year History
