There Is No Word A Poem by Tony Hoagland www.poetryfoundation.org what I already am thinking about is my gratitude for language— how it will stretch just so much and no farther; how there are some holes it will not cover up; how it will move, if not inside, then around the circumference of almost anything— how, over the years, it has given me back all the hours and days, all the plodding love and faith, all the misunderstandings and secrets I have willingly poured into it. languagewords
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