English chemist Humphry Davy developed the first incandescent light in 1802, followed by the first practical electric arc light in 1806.
The lamps produce significant ultraviolet output, they require ventilation when used indoors, and due to their intensity they need protection from direct sight. Invented by Humphry Davy around 1805, the carbon arc was the first practical electric light.
English chemist Humphry Davy developed the first incandescent light in 1802, followed by the first practical electric arc light in 1806.
By the 1870s, Davy's arc lamp had been successfully commercialized, and was used to light many public spaces.
It was used commercially beginning in the 1870s for large building and street lighting until it was superseded in the early 20th century by the incandescent light.
Efforts by Joseph Swan and Thomas Edison led to commercial incandescent light bulbs becoming widely available in the 1880s, and by the early twentieth century these had completely replaced arc lamps. The energy efficiency of electric lighting has increased radically since the first demonstration of arc lamps and the incandescent light bulb of the 19th century.
Low-pressure sodium lights are favoured for public lighting by astronomers, since the light pollution that they generate can be easily filtered, contrary to broadband or continuous spectra. ===Incandescent light bulb=== The modern incandescent light bulb, with a coiled filament of tungsten, and commercialized in the 1920s, developed from the carbon filament lamp introduced about 1880. Less than 3% of the input energy is converted into usable light.
Low-pressure sodium lights are favoured for public lighting by astronomers, since the light pollution that they generate can be easily filtered, contrary to broadband or continuous spectra. ===Incandescent light bulb=== The modern incandescent light bulb, with a coiled filament of tungsten, and commercialized in the 1920s, developed from the carbon filament lamp introduced about 1880. Less than 3% of the input energy is converted into usable light.
The United States Environmental Protection Agency recommends that fluorescent lamps be segregated from general waste for recycling or safe disposal, and some jurisdictions require recycling of them. ===LED lamp=== The solid-state light-emitting diode (LED) has been popular as an indicator light in consumer electronics and professional audio gear since the 1970s.
In the 2000s, efficacy and output have risen to the point where LEDs are now being used in lighting applications such as car headlights and brake lights, in flashlights and bicycle lights, as well as in decorative applications, such as holiday lighting.
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