Sit back and think about the last time you saw a square shaped well. Can you remember? Probably not, because wells are pretty much always round in shape. Humans seem to really like their edges because… well, look around: the room you’re sitting in right now is probably rectangular. That building across the street? Rectangular.
If we asked you to grab a pencil and draw either a perfect circle or a rectangle, what would you draw? Chances are you’ll pick a rectangle, simply because they’re way easier to draw.
So it’s clear. Humans prefer rectangular structures because they’re just convenient to construct. But then what’s up with wells? Why are they (almost always) round?
The physics behind the shape of wells is not as deep (pun intended) as you might think!
How are wells made?
In the past, well diggers would suspend themselves by a board that was attached to a rope attached to a tripod above the hole. To make this hole, they spun around on the rope, digging until their arms reached a certain distance. Once the digging was done, they’d usually build a stone wall inside, above the bedrock layer. This formed two arches, compressing the stones equally.
Modern wells, similarly, are dug with drills and the rotation of the drills make the holes circular. Once the well is dug, it is lined with pipes to create the same arch as the stone walls inside old wells.
However, that isn’t the only reason wells are circular in shape.
Circular wells have stronger walls!
The well has to be strong on the inside. Any structure with edges will have weak spots towards the middle. Squares and rectangles are strong at the corners, but the pressure of the earth surrounding the well would make the walls cave in. The water also exerts pressure on the wall of the well.
And this is the physics behind why the wells you see are always circular in shape!