There is a reason water clocks were difficult and sand timers were easy, and it comes down to a surprising difference between liquids and piles of small solid grains.
A…
There is a process going on beneath almost every lawn, field and garden that is too slow to see and large enough to reshape the ground.
Earthworms eat their way…
There is a category of everyday observation that everybody has seen and that turns out to have no settled explanation, and moths around a light are among the clearest examples.…
There is an image that makes most people wince the first time they see it: a hammer driving nails into a horse's foot.
The reaction is reasonable, and it rests…
There is a question about weathervanes that catches almost everybody out, and it concerns which way the pointer faces.
The natural assumption is that the arrow shows where the wind…
A stair is a compromise between space and effort, and the dimensions that make one comfortable are older than any regulation that now enforces them. Here are fifteen.
1. Every…