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Electric light

technology Maturity 7-9 Vital Level 3 Next article →

An electric light is an electrical device that produces light from electricity. It is the most common way humans create artificial lighting today. Most lamps feature a base made of metal, ceramic, glass, or plastic. This base secures the lamp into the socket of a light fixture. Connections to these sockets often use a screw-thread base or two metal pins. Other designs use metal caps or a bayonet mount to stay in place.

Lamp symbol
Lamp symbol

There are three main categories of electric lights used in modern technology. The first type is the incandescent lamp. These produce light by heating a filament until it becomes white-hot from an electric current. The second type is the gas-discharge lamp. These create light through an electric arc passing through a gas, such as in fluorescent lamps. The third type is the LED lamp. These use a semiconductor to produce light as electrons flow across a band gap.

LEDfilamentLightBulbE27
LEDfilamentLightBulbE27

Incandescent lamps work by using a coiled tungsten filament inside a glass chamber. This chamber is either a vacuum or filled with an inert gas like argon. When electricity flows, the tungsten glows and emits a continuous spectrum of light. However, these bulbs are highly inefficient. Only 2% to 5% of the energy consumed is turned into visible light. The remaining 95% of the energy is lost as heat.

Hagley, St John the Baptist - interior, Mason memorial
Hagley, St John the Baptist - interior, Mason memorial

Gas-discharge lamps offer a more efficient alternative. Fluorescent lamps consist of a glass tube containing mercury vapor or argon under low pressure. Electricity flowing through the tube causes these gases to release ultraviolet energy. The inside of the tube is coated with phosphors. These phosphors emit visible light when they are struck by ultraviolet photons. These systems are much more efficient than incandescent bulbs. They typically use only one-quarter to one-third the power for the same amount of light.

Leuchtstofflampen-chtaube050409
Leuchtstofflampen-chtaube050409

LED technology has changed lighting significantly since its early stages. The first practical LED arrived in 1962, but it could only display deep red colors. It was not efficient enough for general lighting at that time. In 1994, Shuji Nakamura demonstrated the first high-brightness blue LED. This discovery allowed for the creation of the first white LED. Scientists achieved this by using a phosphor coating to convert blue light into lower frequencies. Today, LEDs are used in everything from car headlights to holiday lights.

PILA 9290013873
PILA 9290013873

The history of electric light involves many important inventors and discoveries. In 1799, Alessandro Volta created the voltaic pile, which was the first electric battery. In 1806, Humphry Davy gave a practical demonstration of an arc light. Earlier, in 1840, Warren de la Rue created a bulb using a platinum coil in a vacuum. While efficient, the high cost of platinum made it impractical for everyone to use. In the late 1870s, Joseph Swan and Thomas Edison independently developed functional incandescent lamps. Their rivalry eventually led to a merger called the Edison and Swan Electric Light Company.

Arc lamp-arc 1 PNr°0029
Arc lamp-arc 1 PNr°0029

Further improvements continued throughout the 20th century. In 1912, William D. Coolidge patented the tungsten filament, which became a long-standing standard. In 1934, a team led by George E. Inman built a prototype fluorescent lamp at General Electric. This required intense experimentation with gas pressures and cathode construction. In 2009, Philips introduced the first LED lamps designed to replace standard 60 W screw-in bulbs. This helped drive a global phase-out of inefficient incandescent bulbs. In the United States, electricity usage decreased for five straight years by 2019 due to these changes.

Xenon short arc 1
Xenon short arc 1
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🖼️ Images & Media (10)
File:Lamp symbol.svg
Lamp symbol.svg
File:Lamp symbol, old.svg
Lamp symbol, old.svg
File:This room is equipped with Edison electric light.jpg
This room is equipped with Edison...
File:Hagley, St John the Baptist - interior, Mason memorial.jpg
Hagley, St John the Baptist - interior,...
File:Leuchtstofflampen-chtaube050409.jpg
Leuchtstofflampen-chtaube050409.jpg
File:PILA 9290013873.JPG
PILA 9290013873.JPG
File:Arc lamp-arc 1 PNr°0029.jpg
Arc lamp-arc 1 PNr°0029.jpg
File:Xenon short arc 1.jpg
Xenon short arc 1.jpg
File:Microscope MercuryArcBulb Detail.jpg
Microscope MercuryArcBulb Detail.jpg
File:LEDfilamentLightBulbE27.jpg
LEDfilamentLightBulbE27.jpg
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