He's not dead, he's resting
How Round Is Your Circle?
As everyone knows, a point is that which has no part, a line is a breadthless length, and it is possible to cut a sphere up into a finite number of pieces, move them around and put them back together again to get two spheres identical in every way to the original sphere.
Unfortunately, in reality, points have a size, lines have a width, spheres aren’t spheres and they can’t be cut up into infinitely complicated pieces. How Round Is Your Circle, Where Engineering and Mathematics Meet by John Bryant and Chris Sangwin is an attempt by engineers to convince mathematicians that caring about real world issues can be interesting.
The book covers various practical issues, such as:
- How to draw a straight line, and how to make a ruler
- How to test how circular a circle is
- How to measure area
In the process, it discusses all kinds of cunning gadgetry used in the olden days before digital computers and mass production, from steam engine linkages and pistons to slide rules and draughting devices. It also covers various physical demonstrations of geometric problems, and illustrates what happens when physical inaccuracies are ignored:
It’s certainly an interesting read, although I would have preferred more emphasis on the tools and gadgets used than on demonstrations of things they can be used to make. The maths isn’t particularly heavy, and shouldn’t put too many people off. Similarly, there’s nothing on the engineering side that would be inaccessible to anyone with no engineering background.