Both of these are recent inventions that look obvious in retrospect and took a very long time to arrive, and both do something more specific than they appear to. Here…
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 common assumption about early steam power that inverts the actual mechanism, and correcting it makes the whole development sequence comprehensible.
The assumption is that steam pushes. High-pressure…
There is a piece of physics that almost everybody half-knows and that is more interesting stated precisely.
The half-known version is that things fall faster and faster. That is true…
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 —…