by Goodwin » Tue Sep 17, 2019 3:17 pm
Thank You Chris Peterson! For pointing out that it's a diffraction effect, called Rayleigh scattering, that gives different (& small) diffraction angles for different particle sizes as well as for different wavelengths, and not refraction through water droplets or ice crystals as in rainbows, etc. that gives the same (& larger) angle for a given wavelength, independent of particle size. Rayleigh scattering also accounts for the sky being blue and sunsets red.
A more difficult question is why a guy who used to make a living doing diffraction of X-rays didn't immediately think of that....
Thank You Chris Peterson! For pointing out that it's a diffraction effect, called Rayleigh scattering, that gives different (& small) diffraction angles for different particle sizes as well as for different wavelengths, and not refraction through water droplets or ice crystals as in rainbows, etc. that gives the same (& larger) angle for a given wavelength, independent of particle size. Rayleigh scattering also accounts for the sky being blue and sunsets red.
A more difficult question is why a guy who used to make a living doing diffraction of X-rays didn't immediately think of that....