corrections to discussion about sky glow in lp page and in main sky glow page light is scattered by molecules rayleigh scattering and aerosols not refracted aerosol scattering dominates in most places in clear ir see garstang pasp the total scattering from aerosols is x that from molecules aerosol scattering has almost no wavelength dependence reducing the dominance of blue light influence below that expected from pure rayleigh scattering and the rsi of keith but the purkinje effect makes the eye more sensitive to white blue rich light when dark adapted most relevant when looking at adapted to sky glow only marginally relevant when looking at adapted to outdoor night lighting levels increasing again the dominance of white blue rich sources the bortle scale has made very little or no penetration into professional astronomy astronomers when they characterize skyglow at all still use mag arcsec bortle scale is being used by amateurs and is being investigated in some detail by us national park service as a useful scale to characterize night sky quality finally the bortle scale uses much more than just sky glow to characterize skies