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Light scattering by small particles by H. C. van de Hulst

Light scattering by small particles H. C. van de Hulst ebook
Publisher: Dover Publications
Page: 480
ISBN: 0486642283, 9780486642284
Format: djvu

The scattered light is detected and translated into a particle size by mathematical calculations (either Mie or Fraunhofer). Space doesn't appear blue because there are not enough If you consider the wavelength dependence of scattering for medium-sized particles, you find that for a narrow wavelength range the dependence reverses for a bit. €�We can use this technique of light scattering to detect single airborne fibers that are far too small to be seen with the naked eye,” he says. Light rays can change direction when they encounter small particles, a phenomenon called scattering. This sort of scattering – when the scatterer is considerably smaller than the wavelength of the light – is usually called “Rayleigh scattering”, after the 19th century British physicist Lord Rayleigh. If you smash a clear ice cube, the pile of small pieces appears brighter and whiter than the whole cube. The pattern “is a bit like a thumbprint for the particle,” says Kaye, sometimes making it possible to identify a particle's shape, size, structure, and orientation by looking at the scattered light. If you are not using the right calculation method and correct parameters, this might lead to large over- or underestimation, especially of the presence of small particles! Aerosol particles are much larger than molecules in the air, however, and they scatter red light more strongly, which washes out the blue light scattered by smaller molecules and makes the sky brighter and whiter. The consequences might be severe—for The incident laser light interacts with the particle leading to absorption and scattering.