Electric light

An electric light, lamp, or light bulb is an electrical device that produces light from electricity. It is the most common form of artificial lighting. These lights usually have a base made of ceramic, metal, glass, or plastic that fits into the socket of a light fixture. The connection to the socket can be made in different ways, such as a screw-thread base or a bayonet mount.

There are three main types of electric lights. Incandescent lamps work by heating a filament white-hot with electric current. Gas-discharge lamps, like fluorescent lamps, create light through an electric arc in a gas. LED lamps produce light when electrons move across a band gap in a semiconductor.

The energy efficiency of electric lighting has improved a lot since the first lights were made in the 19th century. Today, there are many kinds and sizes of modern electric light sources for different uses. Most electric lights are powered by electricity made in big power stations, but they can also run on mobile generators or batteries. Battery-powered lights, such as flashlights or electric lanterns, are often used when other lights are not available, like during power outages or when traveling.

History

Before electric lighting became common in the early 20th century, people used candles, gas lights, oil lamps, and fires. In 1799–1800, Alessandro Volta created the voltaic pile, the first electric battery. This led to early experiments with electric lights, such as the first persistent electric arc developed by Vasily Vladimirovich Petrov in 1802.

Later inventors improved electric lighting. In 1840, Warren de la Rue created an early electric light bulb using a platinum coil. In the late 1870s and 1880s, Joseph Swan in the UK and Thomas Edison in the US developed practical incandescent lamps. By the early 20th century, these had replaced earlier arc lamps. Further improvements included the tungsten filament and the first neon lights. The first practical LED arrived in 1962, with high-brightness blue LED demonstrated in 1994, leading to the development of white LEDs for general lighting.

Types

Main article: Incandescent light bulb

Incandescent light bulbs have a thin coil of tungsten inside a glass bulb, either empty or filled with a special gas. When electricity flows through the tungsten, it heats up and glows, making light. However, these bulbs are not very energy-efficient, as most of the electricity is used to create heat instead of light. Because of this, many places are replacing them with more efficient options like LED bulbs.

Main article: Halogen lamp

Halogen lamps are smaller and brighter than regular incandescent bulbs. They use special glass and gases to produce more light with less energy. They also last longer and keep their brightness better over time.

Main article: Fluorescent lamp

Fluorescent lamps are long, thin tubes that use a small amount of mercury and gas to create light. When electricity passes through the tube, it causes the gas to glow, and a special coating on the inside turns that glow into visible light. These lamps are much more energy-efficient than incandescent bulbs but contain mercury, so they need to be disposed of properly.

Main article: LED lamp

LED, or light-emitting diode, lights are very energy-efficient and can last a long time. They have been used in small devices for years and are now used in many bigger lighting applications. LEDs can turn on and off instantly and don’t produce much heat.

Main article: Arc lamp

Carbon arc lamps were one of the first electric lights. They use two carbon rods that create a bright arc of light when they are brought close together and then pulled apart. These lamps were used for street lighting and other bright applications before being replaced by more modern lights.

Main article: Gas-discharge lamp

Discharge lamps, like neon signs, use gas inside a glass tube to create light. Different gases produce different colors. These lamps are very efficient and are often used for street lighting and other large-scale lighting needs. Some types, like low-pressure sodium lamps, produce a strong orange light that is useful for areas where reducing light pollution is important.

Characteristics

Many light bulbs come in standard shapes and sizes, making it easy to choose the right one for different uses. For example, common bulbs might be labeled "A19" for their shape and "E26" for the type of base they have, which helps you match the bulb to the right light socket.

When comparing light bulbs, important factors include how much light they produce (measured in lumens), how much energy they use (measured in watts), and the color of the light they give off (measured in kelvins). The lifespan of a bulb is often listed as the number of hours it can work before it starts to dim or stop working altogether. Some bulbs may last much longer or shorter than the listed lifespan, depending on how they are made and used.

Uses

Electric lamps are not just for lighting; they have many other uses too. For example, they can help plants grow indoors as grow lights, especially in places without natural sunlight like hydroponics systems or for aquatic plants.

They are also used in special ways to help people. Some lamps give off heat and are used in baby incubators or in restaurants. Others are used to help treat health problems like skin conditions or low mood during dark winters.

Cultural symbolism

In Western culture, a lightbulb—especially when it appears lit above someone's head—symbolizes a sudden idea or inspiration.

A styled light bulb is also used as the logo of the Turkish AK Party.