sunlight wiki:
>This article deals with light emitted by the sun, for other meanings see Sunlight (disambiguation) Sunlight in the broad sense is the total spectrum of electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered by the atmosphere, and the solar radiation is obvious as daylight when the Sun is above the horizon. This is usually during the hours known as day. Near the poles in summer, sunlight also occurs during the hours known as night and in the winter at the poles sunlight may not occur at any time. 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.
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Astronomy wiki:
>This article is about the science branch. For information about the magazine, see Astronomy (magazine). Astronomy (Greek: αÏÏÏονομία = άÏÏÏον + νÏμοÏ, astronomia = astron + nomos, literally, "law of the stars") is the science of celestial objects and phenomena that originate outside Earth's atmosphere, such as stars, planets, comets, galaxies, and the cosmic background radiation. It is concerned with the formation and development of the universe, the evolution and physical and chemical properties of celestial objects and the calculation of their motions. Astronomical observations are not only relevant for astronomy as such, but provide essential information for the verification of fundamental theories in physics, such as general relativity theory. Complementary to observational astronomy, theoretical astrophysics seeks to explain astronomical phenomena.
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