Light leaves every point of a subject in all directions. A lens collects some of that and reconverges it, and the entire craft is built on the properties and failures…
There is a useful exercise in considering how recently an ordinary thing became ordinary, and fire on demand is the most striking example available.
Fire itself is extremely old. Reliable…
Almost everything about how a book feels - whether it stays open, how it turns, how heavy it is for its size - was decided during manufacture rather than design.…
Every sound in a room reaches you twice - directly, and then repeatedly as reflections from every surface. What a room sounds like is almost entirely a question of how…
The whole subject is pressure rather than force. The same push applied through a smaller area produces a higher pressure, and a cutting edge exists to make that area as…
The fundamental constraint is that ink is either present or absent. Everything printers have done for a century and a half is a way of simulating tones that the process…