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?
Design means something even broader now. Sometime around World War II, it came to mean making things that “solve problems.” With the influence of mid-century global social movements and the rise of digital technology, it began to mean making things that are “human-centered.” And as of recently, design doesn’t have to involve making things at all. It can just mean a way of thinking.
Of all these developments, the idea of design as a broadly applicable way of thinking—the idea of “design thinking”—may end up being the most influential…At Stanford’s d.school, as cofounder Robert Sutton has said, “design thinking” is often treated “more like a religion than a set of practices for sparking creativity.”