What are the infrared and ultraviolet regions? What is the visible area?

The spectrum released by the sun on weekdays mainly comes from the blackbody radiation spectrum with the absolute temperature on the surface of the sun around 6000 degrees. The wavelength range of visible light is 770-390 nm, and the band of invisible light is 770- 1 1590 nm. Electromagnetic waves with different wavelengths make human eyes feel different colors. We divide wavelengths other than visible light into infrared region and ultraviolet region.

Solar radiation is mainly concentrated in the visible part (0.4 ~ 0.76 micron), infrared (>: 0.76 μ m) and ultraviolet (

770 ~ 622 nm, feeling reddish; 622 ~ 597 nm, orange; 597 ~ 577 nm, yellow; 577 ~ 492 nm, green; 492 ~ 455 nm, indigo blue; 455 ~ 390 nm, purple.

Extended data:

The sun is the most powerful, natural and stable natural radiation source. Its central temperature is 1.5 * 10 7K, and its pressure is about 10 16 Pa. The nucleation reaction from hydrogen to helium takes place inside.

The solar nucleation reaction releases enormous energy, and its total radiation power is 3.8 *10.26w, of which the part received by the earth is about1.7 *10/7w. The solar radiation can be expressed by the solar constant, which is the solar radiation illuminance measured outside the earth's atmosphere at the average distance from the sun to the earth.

Because 1900 has test data, the measured value is almost always 1350W/㎡. After correcting the absorption and scattering of the atmosphere, the surface value of the earth is about two-thirds of this value.

It is generally assumed that the radiation temperature of the sun is 5900K, and its radiation temperature decreases with the increase of wavelength. According to the theory of blackbody radiation, when the temperature of an object rises, the emitted radiation energy increases and the peak wavelength moves to the short wave direction.

The wavelength range of solar radiation covers the entire electromagnetic spectrum from X-rays to radio waves. Outside the atmosphere, the spectral distribution curves of the sun and the 5900K blackbody are similar. Affected by the absorption of various gas components in the atmosphere, the radiation energy of sunlight in some spectral regions will be greatly attenuated when it reaches the earth's surface through the atmosphere, resulting in some depressions in the spectral distribution curve.

References:

Solar spectrum? Baidu baike