Every spring is an intersection between water moving underground and a surface that happens to be in the way. The rock decides where, and everything else follows. Here are fourteen.…
The whole subject is fluid control. Too little and nothing appears; too much and it blots; and the difference between the two is a matter of fractions of a drop.…
Source: Wikipedia
There is a grim regularity to the history of libraries. They accumulate for generations, they hold material that exists nowhere else, and then something happens to them — and…
Source: Wikipedia
Archaeology usually has the opposite problem to this one. Objects survive and their purpose is unclear because nothing organic remains around them.
Here the object survives in extraordinary condition,…
The useful thing to understand is that a crossing point is not a convenience but a bottleneck. Every route in a region funnels toward the few places the river can…
The wheel is frequently described as the great invention. The wheel-and-axle pair is the invention; a disc that rolls is obvious, and attaching it usefully is not. Here are twelve…