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?
Theodor H. Nelson, “As We Will Think." Proceedings of Online 72 Conference, Bruanel University, Uxbridge, England, 1972
What if the exact same information could live and breathe in multiple places? For example, if your company’s process for requesting time off changes, you’d probably have to find all the pages that mention the policy and manually update each of them.
Synced Blocks changes that. Instead of going through and updating the process to request time off in every page it’s referenced, turning it into a Synced Block allows you to update it once and have those changes reflected everywhere. Even though it’s a simple idea, it opens up many possibilities for how information can be structured and shared.