A new sensor for light, heat and touch

Inspired by the behaviour of natural skin, researchers at the Laboratory of Organic Electronics, Linkoping University, have developed a sensor that will be suitable for use with electronic skin. It can measure changes in ...

CLASP-2: Investigating the magnetic solar chromosphere

Four years ago, an international team (USA, Japan and Europe) carried out an unprecedented suborbital space experiment called CLASP-1, motivated by theoretical investigations carried out at the IAC by Javier Trujillo Bueno ...

2-D material has space vehicle applications

A new study from The Australian National University (ANU) has found a number of 2-D materials can not only withstand being sent into space, but potentially thrive in the harsh conditions.

Mining the moon

If you were transported to the Moon this very instant, you would surely and rapidly die. That's because there's no atmosphere, the surface temperature varies from a roasting 130 degrees Celsius (266 F) to a bone-chilling ...

Power stations driven by light

Green plants, algae and some bacteria use sunlight to convert energy. The pigments in chlorophyll absorb electromagnetic radiation, which induces chemical reactions in electrons. These reactions take place in the nucleus ...

China moon rover 'Jade Rabbit' wakes from 'nap'

China's lunar rover got back to work on the far side of the moon Thursday after waking from a five-day hibernation, its official social media page announced.

Health checkups for alpine lakes

The best tool for assessing the health of mountain lakes comes in a very small package. According to new research by University of Alberta biologists, alpine species of zooplankton are excellent bioindicators of lake health. ...

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Sunlight, 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.

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