Reflections: Cool vibes, hot wax

This photo is a seldom seen application of schlieren imaging. It is a vibration pattern on the surface of a layer of molten paraffin wax in a shallow circular Pyrex vessel. The photo was taken with a color reflection schlieren setup where surface irregularities cause the light in the schlieren beam to be deflected by the changes in surface slope of the liquid. The "knife edge" filter array consisted of red, green, and blue filters.