The lightbulb is a commodity that many of us probably take for granted. Like many useful inventions, it has undergone numerous stages of development and incarnations. Here is a brief biography of the lightbulb—the story of its early years over a century ago and its more recent phases of evolution.
Initial Attempts at Electrical Lighting
In the early 1800s, the voltaic pile was invented in Italy. It was one of the first means of generating continuous electricity and is now considered an early battery. Alessandro Volta was its developer and used layers of zinc, copper, cardboard, and salt water to conduct electricity through a copper wire (below).
The copper wire glowed as a result. Soon thereafter, Humphrey Davy combined voltaic piles with charcoal electrodes and Live Science reports that this “invention was known as an electric arc lamp, named for the bright arc of light emitted between its two carbon rods.” In 1835 the first ongoing electric light was produced in Britain with incandescent (emitting light as a result of being heated) bulbs and inventors around the world set about competing to improve the filaments, bulbs, costs, and efficiency. The filament is the part that glows when an electrical current is passed through it, and the bulb, it was discovered, produced differing amounts of light when it was empty or full of gas.
Incandescent Bulbs
The incandescent lightbulb was patented in 1879 and 1880 by Thomas Edison (below).
William Sawyer, Albon Man, and Joseph Swan also held similar patents in the U.S. and England. Edison and these contemporaries resolved patent infringement disputes by joining to become General Electric (Edison with Sawyer and Man of the U.S.) and Ediswan (Edison and Swan in England). Edison and his team’s improvements on the bulb included trying out carbon, then platinum, then bamboo made superior filaments, and efficiently sucking the air of the lightbulb. The screw-in system that Edison developed is still used in the majority of lighting sockets today. Also, he was a central developer of the NYC Pearl Street Power Station, a groundbreaking electrical power utility plant with electric meters available for each customer.
At the beginning of the 20th century, European inventors took center stage in filament experimentation and refinement. In Austria, Carl Auer van Welsbach created the first successful lamp with a metal filament by using osmium for the filament. Tantalum filament lamps came next, from Otto Feuerlien and Werner von Bolton of Germany. Three different tungsten filament lamps came out in 1904 and offered heightened efficiency and light output. American History explains that William Coolidge, “[at] GE’s research lab…developed a process to make bendable (“ductile”) tungsten wire, and in 1910 GE began selling lamps made with this filament.” In 1913, it was discovered by Irving Langmuir that the insertion of nitrogen into a bulb could double the lightbulb’s efficiency.
Fluorescent Lightbulbs
Fluorescent lightbulbs, or bulbs that run on the low-pressure discharge of mercury vapor, evolved from the invention of early discharge lamps in Germany. Heinrich Geissler and Julius Plücker created light in the first discharge lamp by passing electricity through a tube with almost no air in it. This model was tried out in variations by both Edison and his peer and competitor, Nikola Tesla, as well as Peter Cooper Hewitt. Hewitt ran the electrical current through mercury vapor and controlled the flow of the electricity with a ballast. This produced a not very useful bluish-green lighting source. Neon tubes covered by phosphors which could emit visible, white light were made in the 1920s and 1930s. These were first popularly used in the U.S. Army and Navy before becoming more standard in the 1950s. In the 1970s, Edward Hammer of GE realized it was possible to bend the fluorescent tube until it formed the spiral shape with which we are now familiar in the compact fluorescent light (CFL).
The first CFLs were expensive, inconsistent, and hard to fit into fixtures built for incandescent bulbs. These issues have now been largely resolved, and CFLs are cheap, high-performing, and can last many times longer than their incandescent ancestors.
LED Bulbs
LED stands for light-emitting diode. Google Dictionary explains that “a diode is a semiconductor device with two terminals, typically allowing the flow of current in one direction only.” The light in an LED bulb is a result of electroluminescence (light arising in response to an electrical current) in a semiconductor material, such as silicon or germanium, and is known as solid-state lighting because it does not rely on electrical filaments or gas. Colored diodes (red, yellow, green and blue) came first in the 1970s and were used for technical and indicator lighting purposes. In the 1990s, blue diodes were coated with phosphor and so white LEDs were born.
Like their predecessors, their efficiency and cost improved over time and Energystar states that compared to incandescent and compact fluorescent lighting, “when designed well, LED lighting can be more efficient, durable, versatile, and longer lasting.” The U.S. Department of Energy reported in 2014 that, “several manufacturers released ENERGY STAR®-qualified bulbs surpassing 100 lumens [(units of light emitted per second)] per watt,” versus outdated traditional incandescent bulbs, which reached 13 to 18 lumens per watt.
But, as this brief looks at the life of lightbulbs comes to an end, it’s worth noting that, as of December 29, of 2016, an incandescent bulb at Fire Station 6 in Livermore, California is still holding its own as the longest burning lightbulb in history. It’s now in its 115th year of illumination, receives tons of tourist attention, and you can bathe in its magical light at the town of Livermore’s online bulb cam site.
–Julia Travers