There is a fact about the past that is difficult to hold onto because it contradicts something we do daily without thinking.
For most of human history, almost nobody had…
There is a widely held picture of how concrete works, and almost every part of it is inverted.
The picture is that wet concrete is a thick paste which dries…
The starting point is a discrepancy. Atomic bonds are extremely strong and the materials made of them are not, by a factor of ten or more - and everything below…
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 single fact that organises the subject is that magnetism is produced by moving electric charge, and every electron is both moving and carrying an intrinsic property that behaves like…
The useful distinction is between materials that store energy in their shape and materials that store it in their disorder. A spring does the first and rubber does the second,…