The coastline paradox is the dependence of a country's measured coastline length on the length of the ruler used. First considered by L. F. Richardson
(1881-1953), it is sometimes known as the Richardson effect (Mandelbrot 1983, p. 28).
A shorter ruler measures more of the sinuosity of bays
and inlets than a larger one, so the estimated length continues to increase as the
ruler length decreases.
In fact, a coastline is an example of a fractal, and plotting the length of the ruler versus the measured length
of the coastline on a log-log plot gives a straight line, the slope of which is the
fractal dimension of the coastline (and will
be a number between 1 and 2).
