The film is not a solid thing. It is a layer of water held between two surfaces, and everything a bubble does - its shape, its colours, its lifespan and…
There is a question about corrosion that people rarely ask and that turns out to be the whole subject.
The question is not why metals corrode. Almost all of them…
Combustion is a push. Everything in an engine exists to convert a series of pushes into smooth rotation, at speed, repeatedly, while managing the heat and friction that produces. Here…
There is a widespread assumption about roads that is understandable and backwards.
The assumption is that the hard black surface is the road, and that what lies beneath it is…
A moving bicycle with nobody on it can stay upright for a considerable distance, correcting itself when pushed. Working out why took far longer than anybody expected, and the popular…
There is a useful principle about signals that applies well beyond sound, and whistles are the clearest everyday demonstration of it.
The principle is that being heard is a matter…