Changes

==Origin==

==Origin==

West Frisian ''sinneljacht'', Middle Dutch ''sonnelicht'', (Dutch ''zonlicht''), Old High German ''sunnalioht'' and ''sunnûn lioht''

West Frisian ''sinneljacht'', Middle Dutch ''sonnelicht'', (Dutch ''zonlicht''), Old High German ''sunnalioht'' and ''sunnûn lioht''

*[http://en.wikipedia.org/wiki/13th_century 13th Century]

*[https://en.wikipedia.org/wiki/13th_century 13th Century]

==Definition==

==Definition==

1 : the [[light]] of the [[sun]] : sunshine  

1 : the [[light]] of the [[sun]] : sunshine  

==Description==

==Description==

'''Sunlight''', in the broad sense, is the total [[frequency]] [[spectrum]] of [[electromagnetic]] radiation given off by the [[Sun]], particularly [http://en.wikipedia.org/wiki/Infrared infrared], visible, and [http://en.wikipedia.org/wiki/Ultraviolet ultraviolet] light. On [[Earth]], sunlight is filtered through the [[Earth]]'s [[atmosphere]], and solar [[radiation]] is obvious as daylight when the Sun is above the [[horizon]].

'''Sunlight''', in the broad sense, is the total [[frequency]] [[spectrum]] of [[electromagnetic]] radiation given off by the [[Sun]], particularly [https://en.wikipedia.org/wiki/Infrared infrared], visible, and [https://en.wikipedia.org/wiki/Ultraviolet ultraviolet] light. On [[Earth]], sunlight is filtered through the [[Earth]]'s [[atmosphere]], and solar [[radiation]] is obvious as daylight when the Sun is above the [[horizon]].

When the direct solar radiation is not blocked by [[clouds]], it is experienced as sunshine, a combination of bright [[light]] and radiant [[heat]]. When it is blocked by the clouds or [[reflects]] off of other objects, it is experienced as [[diffused]] light.

When the direct solar radiation is not blocked by [[clouds]], it is experienced as sunshine, a combination of bright [[light]] and radiant [[heat]]. When it is blocked by the clouds or [[reflects]] off of other objects, it is experienced as [[diffused]] light.

The [http://en.wikipedia.org/wiki/World_Meteorological_Organization World Meteorological Organization] uses the term "sunshine duration" to mean the cumulative [[time]] during which an area receives direct irradiance from the [[Sun]] of at least 120 watts per square meter.

The [https://en.wikipedia.org/wiki/World_Meteorological_Organization World Meteorological Organization] uses the term "sunshine duration" to mean the cumulative [[time]] during which an area receives direct irradiance from the [[Sun]] of at least 120 watts per square meter.

Sunlight may be recorded using a [http://en.wikipedia.org/wiki/Sunshine_recorder sunshine recorder], [http://en.wikipedia.org/wiki/Pyranometer pyranometer] or [http://en.wikipedia.org/wiki/Pyrheliometer pyrheliometer]. Sunlight takes about 8.3 minutes to reach the Earth.

Sunlight may be recorded using a [https://en.wikipedia.org/wiki/Sunshine_recorder sunshine recorder], [https://en.wikipedia.org/wiki/Pyranometer pyranometer] or [https://en.wikipedia.org/wiki/Pyrheliometer pyrheliometer]. Sunlight takes about 8.3 minutes to reach the Earth.

On [[average]], it takes energy between 10,000 and 170,000 years to leave the [[sun]]'s interior and then be emitted from the [[surface]] as [[light]].

On [[average]], it takes energy between 10,000 and 170,000 years to leave the [[sun]]'s interior and then be emitted from the [[surface]] as [[light]].

Direct sunlight has a luminous efficacy of about 93 lumens per watt of [http://en.wikipedia.org/wiki/Radiant_flux radiant flux]. Bright sunlight provides illuminance of approximately 100,000 lux or lumens per square meter at the Earth's surface.

Direct sunlight has a luminous efficacy of about 93 lumens per watt of [https://en.wikipedia.org/wiki/Radiant_flux radiant flux]. Bright sunlight provides illuminance of approximately 100,000 lux or lumens per square meter at the Earth's surface.

Sunlight is a key factor in [http://en.wikipedia.org/wiki/Photosynthesis photosynthesis], a [[process]] vital for many living [[beings]] on [[Earth]].[http://en.wikipedia.org/wiki/Sunlight]

Sunlight is a key factor in [https://en.wikipedia.org/wiki/Photosynthesis photosynthesis], a [[process]] vital for many living [[beings]] on [[Earth]].[https://en.wikipedia.org/wiki/Sunlight]

[[Category: Physics]]

[[Category: Physics]]