The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a principal source of vitamin D3 and a mutagen.
Researchers may record sunlight using a sunshine recorder, pyranometer, or pyrheliometer.
Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun.
A photon starting at the centre of the Sun and changing direction every time it encounters a charged particle would take between 10,000 and 170,000 years to get to the surface.
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