Rayleighsäteily

Rayleighsäteily is a term that refers to elastic scattering of electromagnetic radiation by particles much smaller than the wavelength of the radiation. This phenomenon is named after the British physicist Lord Rayleigh. It is responsible for the blue color of the sky and the red color of sunsets. When sunlight enters Earth's atmosphere, the gas molecules, primarily nitrogen and oxygen, scatter the shorter, blue wavelengths of light more effectively than the longer, red wavelengths. This preferential scattering of blue light makes the sky appear blue to our eyes. During sunrise and sunset, sunlight travels through a greater thickness of the atmosphere. This longer path causes most of the blue light to be scattered away, allowing the longer, red and orange wavelengths to reach our eyes directly, resulting in colorful sunsets. Rayleigh scattering also plays a role in the polarization of skylight. The intensity of Rayleigh scattered light is inversely proportional to the fourth power of the wavelength, meaning shorter wavelengths are scattered much more strongly than longer ones. This principle is fundamental in understanding atmospheric optics and has applications in various fields, including remote sensing and astrophysics.