The quest for artificial light dates back to when man first learned to control fire. Even the Greeks experimented with static electricity. Ask just about anyone about the inventor of the light bulb and they will most likely name Thomas Edison. However, many other people researched and experimented with electric lighting before him. Back in 1710, British scientist Francis Hauksbee used static electricity to produce a glow in a hollow glass globe exhausted of its air. In 1802, a British chemist called Humphry Davy had figured out how to create an incandescent light source by using a piece of platinum. Unfortunately, his light was dull and only lasted a short time, which was not very useful at all. Michael Faraday, working in Britain, and American, Joseph Henry, independently discovered the principle of electromagnetic induction in 1831, leading to the development of the dynamo as a source of electric power.

Moving forward to 1835, James Bowman Lindsay, an inventor from Scotland, developed an electric light that was much brighter and it could last a longer time too. However, he still found that it had some problems and became too involved with other projects to fine-tune his light. Over the next several decades, many others experimented with platinum coils, carbon filaments, and other devices, but none of them could make a product perfect or affordable enough to mass produce. By 1850, Joseph Swan, an English chemist, found a way to make a bulb with a vacuum pump so that the glass did not become blackened. During the 1870s, a man named Charles Francis Brush continued where Humphry Davy left off and tried to find a way to improve on his electric light invention. He created the Brush Electric Company during 1880.

Around the same time, Thomas Edison had been doing plenty of research to create an incandescent light that could be mass produced in a practical way. Before this, several people and buildings were already using light bulbs developed by Joseph Swan. Later, Edison merged with Swan's company. As he continued his search for a lighting system, he re-built the dynamo to reach 90 percent efficiency (previously 50 percent was optimum), which produced 110 volts, higher than the voltage used by other inventors. During 1879, Edison began experiments on a variety of carbonized filaments and along the way, Lewis Howard Latimer joined Edison. They found that gases were being given off by the filaments during operation, destroying the vacuum in the bulb, and shortening the duration the filament would remain illuminated. So they created a carbon filament that allowed light bulbs to last much longer. In a demonstration on October 19, 1879 Edison turned on the current and his lamp began to glow. It continued glowing for 40 hours. Other inventors were still producing lamps that glowed for only a few minutes. The date usually given as the time of invention of this first lamp was October 21, when the test was completed. Public announcement of the invention appeared on December 21, 1879 on the front page of the New York Herald. A public demonstration was held at Edison's Menlo Park, N.J. laboratory on New Year's Eve.

How it Works

Light bulbs contain a filament, or a metal coil, inside the glass bulb. Electricity is passed through wires into the bulb. In this way, it causes the filament to heat up. When this coil is very hot, it glows and produces light. The glass of the bulb is very important for two reasons. It prevents the filament from setting fire to any surrounding objects, and it also prevents air from reaching the coil. If air comes in contact with a hot filament, it could produce fire and burn out right away.

Energy Efficient Light Bulbs

Incandescent light bulbs actually use quite a lot of energy in order to produce light. When we use a lot of energy, we increase pollution and greenhouse gases which harm the environment. To address this problem, some manufacturers and researchers came up with the solution of using compact fluorescent lights. Instead of using a filament, the spiral bulb is filled with a gas. Almost as soon as it comes in contact with electricity, it lights up. In this way, CFLs use less energy and also last a lot longer than incandescent light bulbs.

References

• Thomas Edison – Learn about Thomas Edison's life and inventions.
• Edison's Invention – Find out who worked alongside Edison to help with his inventions.
• Using an article from pa.msu.edu – This quick explanation covers incandescent and fluorescent bulbs.
• Light Bulb Comparison – Watch a demonstration that shows how efficient different light bulbs are.
• Types of Bulbs – Which of these bulbs do you think is best to use?
• Using CFLs – See how using a CFL bulb can make a difference to our planet.
• Using CFLs video from nationalgeographic.com – See how using a CFL bulb can make a difference to our planet.
• Incandescent Lights – Find out all about incandescent bulbs from its history to facts and inventor.
• Humphry Davy – Read a brief biography about Humphry Davy and his experiments with artificial light sources.
• Charles Francis Brush – Explore Brush's background and his work with electric light.