How Does A Light Bulb Work
Nathan M.
2012








Incandescent light bulbs work with a filament. The electricity comes in through the input at the bottom. The electricity is then carried through wires to the filament, a thin coiled piece of tungsten. The electricity goes through the filament so fast that it can’t all fit. The access energy turns into heat. This heat heats up the tungsten and causes it to glow. The reason that the filament doesn't melt is because tungsten is an extremely heat resistant metal. The tungsten can withstand up to 4,500 Fahrenheit. The filament glows because metal has a property that causes it to glow when it gets very hot. The light travels to our eyes and we see it. There was a problem though, the filaments slowly disintegrated and covered the glass in black particles. So now the bulbs are filled with an inert gas such as argon to bounce the particles right back at the filament.
light bulb 1.jpg
Figure 1 incandescent light bulb




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Figure 2 diagram of bulbs

Florescent
Florescent bulbs don’t use filaments; they use argon and mercury gasses. Electricity is pumped in from wires into the glass tube. The electricity flows through the tube and excites the argon gas. The gas turns into an ion. The mercury then collides with the ion and creates a glowing plasma. The plasma gives off ultraviolet light which is invisible to the human eye. The ultraviolet light hits the coating of phosphorous dust on the inside of the tube. The dust glows when exited so it glows and creates visible light. A special type of florescent light is used to make neon signs.
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Figure 3 florescent

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Figure 4 compact florescent


Thomas Edison
Thomas Alva Edison was born February 11, 1847 and died October 18, 1931. He was the famous inventor of the incandescent light bulb. He was inspired to invent the light bulb when thought of the idea of artificial light, a light not naturally emitted. He tried for years to figure out how to create the light and then it hit him, electricity! Once he had a basic design he searched for the right filament to do the job, but everything he tried seemed to catch fire or melt. In 1879 he got it! A piece of cotton thread burned for thirteen and a half hours. It let out a solitary glow that lit up areas in a flash! From then on the incandescent light bulb is still the most popular artificial light.
Glossary
Florescent: visible light created using heat
Incandescent: visible light created without using heat
Inert gas: Gasses with the element of helium in the periodic table
Phosphorescent: Something that emits light




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