Everything difficult about a watch comes from being small, portable and attached to somebody. The timekeeping principles are the same as a clock; the conditions are entirely different. Here are…
The shaft is not holding the canopy up. A sliding collar pushes struts outward, those push the ribs out, and the fabric between them is stretched tight - which is…
There is a widespread mental model of a kite that treats the string as a leash, restraining something that would otherwise escape.
That model produces a specific prediction: cut the…
There is a useful question to ask about any everyday object: what did people do before it, and did they think they had a problem?
For most tools the answer…
Everything is built around a solid form, and everything afterwards is a set of conflicting requirements settled in a particular way. Here are fifteen decisions inside any pair.
1. It…
There is a small category of objects that are fully explained by one diagram, and this is one of them.
A vacuum flask is a container inside another container, with…