There is a useful test of how hard something is to make: look at what people did before they had it.
Before metal needles, sewing was done with points made…
There is a tool so ordinary that almost nobody has considered how it works, and the answer turns out to be more particular than expected.
The obvious model is a…
Every surface in a home collects the same grey film, and it is a record of everything that has been shed, tracked in or blown through recently. Here are fifteen…
Almost every visible feature of a transmission line is a solution to one of two problems: keeping the electricity in the wire, and keeping the wire in the air. Here…
A stair is a compromise between space and effort, and the dimensions that make one comfortable are older than any regulation that now enforces them. Here are fifteen.
1. Every…
The air around you is holding water you cannot see, and the amount it can hold depends almost entirely on temperature. Cool it enough and the water has to go…