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 useful question at any reservoir is why the wall is where it is, because that position was chosen for reasons of geology and geometry that determined everything else. Here…
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…
The conversion of sound to signal was solved early and has changed comparatively little in principle. Connecting any telephone to any other took a century of engineering. Here are fourteen…
The idea that fixes everything else is that suction does not pull. Removing air from a tube lets the surrounding atmospheric pressure push liquid up into it, and the atmosphere…
The single idea that makes all of this make sense is that cold is not a thing being added but heat being taken away and put somewhere else. Everything below…