The conversion of sound to signal was solved early and has changed comparatively little in principle. Connecting any telephone to any other took a century of engineering. Here are fourteen…
There is a small category of technologies where the modern industrial version does exactly what the original did, only faster, and paper is the clearest example.
Most processes have been…
The useful question at any market is who it exists to serve, because the answer determines the hour it operates, its position in a town and whether you are a…
The principle is simple: spoilage organisms need water, and removing it stops them. Everything interesting about drying is what else happens while the water is leaving. Here are sixteen.
1.…
There is an old puzzle about a ship whose planks are replaced one at a time until none of the original timber remains, and the question of whether it is…
There is a category of historical evidence that is systematically misleading in a way nobody notices, and early photographs are the clearest case.
A photograph feels like direct evidence. It…