How many colors does sunlight have?

Through the prism, we can see that sunlight has seven colors, which are red, orange, yellow, green, cyan, blue and purple. This is visible light.

The time of sunlight exposure can be recorded by camera, all-sky radiometer or heliometer. It takes 8.3 minutes for sunlight to reach the earth from the sun.

The spectral range of surface illumination depends on the influence of the atmosphere on the height of the sun. The dusk around sunrise and sunset depends on the blue spectral components dominated by atmospheric scattering, while red light dominates the color of sunrise and sunset. These effects are obvious in natural light photography, where the illumination is sunlight through the atmospheric medium in principle.

Extended data:

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The brightness efficiency of direct sunlight is about 93 lumens per watt, including infrared, visible and ultraviolet rays. Bright sunlight provides illumination on the earth's surface of about per square meter 100000 lumens or 100000 lux. Sunlight is the key factor of photosynthesis and is very important to life on earth.

The solar radiation spectrum of the sun is very close to that of a blackbody with a temperature of 5,800 K. About half of the electromagnetic spectrum is in the short-wave range of visible light, the other half is in the near infrared region, and there are some ultraviolet rays in the spectrum. When ultraviolet rays are not absorbed by the atmosphere or other protective coatings, it may lead to sunburn or self-regulation changes of human skin pigments.

References:

Baidu Encyclopedia-Sunshine-Composition