Sunlight
hideSunlight, in the broad sense, is the total spectrum of the electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the atmosphere, and the solar radiation is obvious as daylight when the Sun is above the horizon. Near the poles in summer, the days are longer and the nights are shorter or non-existent. In the winter at the poles the nights are longer and for some periods of time, sunlight may not occur at all. When the direct radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and heat. Radiant heat directly produced by the radiation of the sun is different from the increase in atmospheric temperature due to the radiative heating of the atmosphere by the sun's radiation. Sunlight may be recorded using a sunshine recorder, pyranometer or pyrheliometer. Sunlight takes about 8.3 minutes to reach the Earth. The World Meteorological Organization defines sunshine as direct irradiance from the Sun measured on the ground of at least 120 watts per square metre.
Direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux, which includes infrared, visible, and ultra-violet light. Bright sunlight provides luminance of approximately 100,000 candela per square meter at the Earth's surface.
Sunlight is a key factor in photosynthesis, a process crucially important for life on Earth.
For more information about Sunlight, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with sunlight
Scientists grow solar cell components in tobacco plants
Nanotechnology / Bio & Medicine
Jan 29, 2010 |
4.5 / 5 (30) |
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(PhysOrg.com) -- Over billions of years, plants have evolved very efficient sunlight-collecting systems. Now, scientists are trying to harness the finely tuned systems in tobacco plants in order to use them ...
Bigger corn plants bully smaller neighbors in no-till fields
Jan 25, 2010 |
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It might not look like there's much going on in those roadside corn fields, but a Purdue University researcher has shown that corn plants are in a fierce battle with each other for resources.
Green sea slug makes chlorophyll like a plant
Jan 12, 2010 |
4.8 / 5 (44) |
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(PhysOrg.com) -- Scientists from the University of South Florida in Tampa have found a green sea slug is able to synthesize chlorophyll like a plant, which makes it the first animal known to be capable of ...
Largest solar panel plant in US rises in Fla.
Oct 24, 2009 |
3.9 / 5 (23) |
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(AP) -- Greg Bove steps into his pickup truck and drives down a sandy path to where the future of Florida's renewable energy plans begin: Acres of open land filled with solar panels that will soon power thousands ...
Color-changing roof tiles absorb heat in winter, reflect it in summer
Oct 08, 2009 |
4.6 / 5 (19) |
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(PhysOrg.com) -- Anyone who has ever stepped barefoot onto blacktop pavement on a hot sunny day knows the phenomenon very well: Black surfaces absorb the sun's heat very efficiently, producing a toe-scorching ...
Catastrophic Darkness: How Life Survives an Asteroid Impact
Space & Earth / Space Exploration
Sep 10, 2009 |
4.5 / 5 (6) |
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A dinosaur-killing asteroid may have wiped out much of life on Earth 65 million years ago, but now scientists have discovered how smaller organisms might have survived in the darkness following such a catastrophic ...
MSU scientists to design optics for new solar mission
Space & Earth / Space Exploration
Aug 31, 2009 |
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Montana State University scientists are involved in a new space mission to figure out how energy is transferred through the sun's atmosphere.
43 percent: New solar power world record
Aug 27, 2009 |
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(PhysOrg.com) -- Australian and US solar cell researchers have achieved the highest efficiency for solar power, setting a new world record of 43 per cent of sunlight converted into electricity.
Under a cloud -- darkness linked to 'brain drain' in depressed people
Medicine & Health / Psychology & Psychiatry
Jul 28, 2009 |
5 / 5 (4) |
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A lack of sunlight is associated with reduced cognitive function among depressed people. Researchers writing in BioMed Central's open access journal Environmental Health used weather data from NASA satellites to measure sunlig ...
MSU scientists to design optics for new solar mission
Space & Earth / Space Exploration
Jul 24, 2009 |
5 / 5 (1) |
1
(PhysOrg.com) -- Montana State University scientists are involved in a new space mission to figure out how energy is transferred through the sun's atmosphere.
NTT DOCOMO Develops Solar-powered Handset
Electronics / Consumer & Gadgets
Jul 15, 2009 |
1 / 5 (1) |
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NTT DOCOMO, Japan's largest mobile operator, announced today its development of the SOLAR HYBRID (docomo STYLE series SH-08A), a solar-powered, waterproof mobile phone that will go on sale in Japan from September.
Vitamin D deficiency is widespead and on the increase
Jun 30, 2009 |
3.6 / 5 (5) |
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A new report issued by the International Osteoporosis Foundation (IOF) and published in the scientific journal Osteoporosis International, shows that populations across the globe are suffering from the impact of low levels ...
Sunlight Trap Could Lead to New Generation of Solar Devices
Jun 11, 2009 |
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In the Greek legend of Dionysius' ear, Dionysius made a cave shaped like an ellipse in order to hear the words whispered by a prisoner in one of the foci of the cave. Some science museums today feature a similar ...
Lettuce gets a healthy suntan
May 18, 2009 |
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Salad dressing aside, a pile of spinach has more nutritional value than a wedge of iceberg lettuce. That's because darker colors in leafy vegetables are often signs of antioxidants that are thought to have a variety of health ...
Anti-aging cosmetic reduced wrinkles in clinical trial
Apr 28, 2009 |
4 / 5 (1) |
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Scientists testing a cosmetic anti-ageing product sold on the high street have shown it can clinically reduce wrinkles and improve the appearance of skin damaged by everyday exposure to sunlight.
