Night

Night or nighttime is the period of time between the sunset and the sunrise when the Sun is below the horizon. This occurs after dusk. The opposite of night is day (or "daytime" to distinguish it from "day" as used for a 24-hour period). The start and end points of time of a night vary based on factors such as season, latitude, longitude and timezone.

At any given time, one side of the planet Earth is bathed in light from the Sun (the daytime) and the other side of the Earth is in the shadow caused by the Earth blocking the light of the sun. This shadow is what we call the darkness of night. Natural illumination is still provided by a combination of moonlight, planetary light, starlight, diffuse zodiacal light, gegenschein, and airglow. In some circumstances, bioluminescence, aurorae and lightning can provide some illumination. The glow provided by artificial illumination is sometimes referred to as light pollution because it can interfere with observational astronomy and ecosystems.

Read more about Night:  Duration and Geography, On Other Celestial Bodies, Impact On Life

Famous quotes containing the word night:

    This will last out a night in Russia
    When nights are longest there.
    William Shakespeare (1564–1616)

    Because of something told under the famished horn
    Of the hunter’s moon, that hung between the night and the day,
    To dream of women whose beauty was folded in dismay,
    Even in an old story, is a burden not to be borne.
    William Butler Yeats (1865–1939)

    The old priest Peter Gilligan
    Was weary night and day;
    For half his flock were in their beds,
    Or under green sods lay.
    William Butler Yeats (1865–1939)