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.
A piece of milled plexiglass acting as a projecting lens; via the Computer Graphics and Geometry Lab at the École Polytechnique Fédérale de Lausanne
New milling techniques applied to glass and plexiglass panels could be used to “create windows that are also cryptic projectors, summoning ghostly images from sunlight.”
[Pauly and Bompas] hope that the technique will be used in architectural design, to create windows that mould sunlight and throw images or patterns onto walls or floors,” which, if timed, milled, and manipulated just right, could produce a slowly animated sequence of images being projected by an otherwise empty window during different times of day.
To control the shape of a caustic pattern generated by a specular or refractive surface, we need to solve the inverse problem: how can we change the surface geometry, such that incident light is redirected to produce a desired caustic image?
Choi: I love [this contemporary banana cream pie] because sometimes new presentations create that iconic or nostalgic thing, but then they don't taste like nostalgia. But this one tastes like a banana cream pie.
Puck: So many young chefs today forget that food has to be delicious. If it's not delicious, why do it? If it's just interesting, you go once, that's it – "okay, I get it, but I don't want to go back."
Choi: I hear you chef. That's what I teach my cooks. I say, "You can do anything you want, but if you can't beat a banana cream pie, then the banana cream pie still wins." In most cases they don't. They can't beat the original.