**Beyond Newton, Part 12.**

*Note: this is about mathematics. It is not intended to tax you in the way school demanded of you.*

We’re taught at school about the ratio of the diameter of a circle to its circumference. Roll a plate on its side and having marked a point on its perimeter, the length it travels by the time it reaches that point again is around 3.14; actually it’s a fraction more. But with a dinner plate of 30cms diameter the difference would be a little over half a millimetre. Not enough for any serious schoolchild to worry about. “A little over three” would suffice here.