The Scintillation of Stars

THE observational evidence provided in the letters which have appeared under this heading in Nature of April 29 and earlier suggests to a meteorologist that scintillation may be associated with waves at an interface between two currents of air. It is rather unlikely to be associated with turbulence because in a turbulent (that is, well-mixed) atmosphere the light from the star from one moment to another, passing, as it does, through thousands of random eddies, would be most unlikely to vary appreciably or in any systematic manner.