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?
Once you’ve had a taste of effortless updates, it’s awfully hard to back to manual everything.
So they didn’t.
And neither did thousands of their peers. It just simply wasn’t worth it. The inertia was too strong.
The old web, the cool web, the weird web, the hand-organized web… died.
And the damn reverse chronology bias — once called into creation, it hungers eternally — sought its next victim. Myspace. Facebook. Twitter. Instagram. Pinterest, of all things. Today these social publishing tools are beginning to buck reverse chronological sort; they’re introducing algorithm sort, to surface content not by time posted but by popularity, or expected interactions, based on individual and group history. There is even less control than ever before.
There are no more quirky homepages.
There are no more amateur research librarians.
All thanks to a quirky bit of software produced to alleviate the pain of a tiny subset of a very small audience.