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:
“What were our praise to them? They eat
Quiet’s wild heart, like daily meat;
Who when night thickens are afloat
On dappled skins in a glass boat,
Far out under a windless sky;
While over them birds of Aengus fly....”
—William Butler Yeats (1865–1939)