Two materials are held apart in a state where one wants to give up electrons and the other wants to take them, and the separation is the entire trick. Here…
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 picture most people have of a watermill that misses the part that mattered.
The picture is a wheel turning in a river, driven by the current —…
There is a difference between materials that are gathered and materials that are extracted, and it explains why some textiles were cheap and others were not.
Wool is gathered. It…
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…
There is a category of object where the useful part is the absence rather than the substance, and netting is the clearest example.
A net is mostly nothing. The material…