Search results
Results from the WOW.Com Content Network
Midtown Manhattan during civil twilight, demonstrating blue hour. Civil twilight is the period of time for which the geometric center of the Sun is between the horizon and 6° below the horizon. [3] [4] [5] Civil twilight is the period when enough natural light remains so that artificial light in towns and cities is not needed.
Blue hour at the Old Cathedral of the Holy Name of Jesus, Bragança in Portugal. The blue hour (from French l'heure bleue; [1] [a] pronounced [lœʁ blø]) is the period of twilight (in the morning or evening, around the nautical stage) when the Sun is at a significant depth below the horizon.
The word crepuscular derives from the Latin crepusculum ("twilight"). [3] Its sense accordingly differs from diurnal and nocturnal behavior, which respectively peak during hours of daytime and night. The distinction is not absolute, because crepuscular animals may also be active on a bright moonlit night or on a dull day.
In folklore, the witching hour or devil's hour is a time of night that is associated with supernatural events, whereby witches, demons and ghosts are thought to appear and be at their most powerful. Definitions vary, and include the hour immediately after midnight and the time between 3:00 am and 4:00 am.
Civil polar twilight in Ruka, Finland at noon in December. The length of polar night varies by latitude from 24 hours just inside the polar circles to 179 days at the poles. As there are various kinds of twilight, there also exist various kinds of polar twilight that progress towards true polar night. Each kind of polar night is defined as when ...
The period of twilight is shortest at the Equator, where the equinox Sun rises due east and sets due west, at a right angle to the horizon. Each stage of twilight (civil, nautical, and astronomical) lasts only 24 minutes. From anywhere on Earth, the twilight period is shortest around the equinoxes and longest on the solstices. [citation needed]
An hour (symbol: h; [1] also abbreviated hr) is a unit of time historically reckoned as 1 ⁄ 24 of a day and defined contemporarily as exactly 3,600 seconds . There are 60 minutes in an hour, and 24 hours in a day. The hour was initially established in the ancient Near East as a variable measure of 1 ⁄ 12 of the night or daytime.
Scattered, diffuse sunlight remains in the sky after sunset and into twilight. [14] The drainage basin of the Nile River and delta at night. There are multiple ways to define twilight, the gradual transition to and from darkness when the Sun is below the horizon. [15] "Civil" twilight occurs when the Sun is between 0° and 6° below the horizon.