Sunlight

related topics
{math, energy, light}
{island, water, area}
{disease, patient, cell}
{specie, animal, plant}
{acid, form, water}
{water, park, boat}
{day, year, event}
{@card@, make, design}
{food, make, wine}
{rate, high, increase}
{ship, engine, design}
{build, building, house}
{woman, child, man}
{car, race, vehicle}
{style, bgcolor, rowspan}


Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. 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.

The 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.[1]

Sunlight may be recorded using a sunshine recorder, pyranometer or pyrheliometer. Sunlight takes about 8.3 minutes to reach the Earth.

Direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux, which includes infrared, visible, and ultraviolet light. 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 photosynthesis, a process vital for life on Earth.

Contents

Full article ▸

related documents
Natural satellite
X-ray astronomy
Sunspot
Precession
Refractive index
Parabola
Degenerate matter
Stefan–Boltzmann law
Thermodynamics
Soliton
Angular velocity
Flux
Tachyon
Wormhole
Beer-Lambert law
Muon
Sirius
Relative density
Latitude
Hyperbola
Viscometer
Gravitational redshift
Sphere
DESY
Quantum chromodynamics
Ideal gas
Equation of state
Apparent magnitude
Inductor
Pauli exclusion principle