The glow of grime Of course this 'sheen of antiquity' of which we hear so much is in fact the glow of grime. In both Chinese and Japanese the words denoting this glow describe a polish that comes of being touched over and over again, a sheen produced by the oils that naturally permeate an object over long years of handling—which is to say grime. If indeed 'elegance is frigid', it can as well be described as filthy. Jun'ichirō Tanizaki & Thomas J. Harper, In Praise of Shadows timeaestheticsfilthflaws
Caustic (optics) Caustics made by the surface of water. In optics, a caustic is the envelope of light rays reflected or refracted by a curved surface or object, or the projection of that envelope of rays on another surface. The caustic is a curve or surface to which each of the light rays is tangent, defining a boundary of an envelope of rays as a curve of concentrated light. Wikipedia en.wikipedia.org Architectural CausticsCaustic Engineering caustics