Meaning of LIGHT in English


That portion of the electromagnetic spectrum visible to the human eye.

It ranges from the red end to the violet end of the spectrum, with wavelengths from 700 to 400 nanometres and frequencies from 4.3/n×/n10 14 to 7.5/n×/n10 14 Hz. Like all electromagnetic radiation , it travels through empty space at a speed of about 186,000 mi/sec (300,000 km/sec). In the mid-19th century, light was described by James Clerk Maxwell in terms of electromagnetic waves, but 20th-century physicists showed that it exhibits properties of particles as well; its carrier particle is the photon . Light is the basis for the sense of sight and for the perception of colour . See also optics ; wave-particle duality .


[c mediumvioletred] (as used in expressions)

light fixture

light quantum

light emitting diode

light frame construction

light year

{{link=zodiacal light">zodiacal light

Britannica English dictionary.      Английский словарь Британика.