Why is the sunset red?

The sunset appears red because the sunlight obliquely enters the atmosphere at sunset, and the path through the atmosphere is significantly longer than at noon. During this process, blue and purple light with shorter wavelengths are dispersed in various directions due to strong scattering by air molecules, making it almost impossible to directly reach the observer's eyes along the original direction; Red and orange light with longer wavelengths are less affected by scattering, have stronger penetration, and can pass through thick atmospheres to reach the ground. Therefore, the direct sunlight we see and the clouds illuminated by it appear reddish orange. The process of sunlight scattering was simulated in the pipeline: white light enters the pipeline and scatters in the transparent gel liquid, mainly scattering blue light near the light source, making the liquid appear blue; The farther away from the light source, the weaker the blue light, leaving behind longer wavelength red orange light, so the liquid at the far end appears orange red.

The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.

The sunset appears red because the sunlight obliquely enters the atmosphere at sunset, and the path through the atmosphere is significantly longer than at noon. During this process, blue and purple light with shorter wavelengths are dispersed in various directions due to strong scattering by air molecules, making it almost impossible to directly reach the observer's eyes along the original direction; Red and orange light with longer wavelengths are less affected by scattering, have stronger penetration, and can pass through thick atmospheres to reach the ground. Therefore, the direct sunlight we see and the clouds illuminated by it appear reddish orange.