Imagine an infinite line and a spinner[1] a short distance away from it. Spin the spinner, wait for it to stop, and then mark the point on the line that the spi

Imagine an infinite line and a spinner[1] a short distance away from it. Spin the spinner, wait for it to stop, and then mark the point on the line that the spinner is point directly at (or away from). Repeat lots of times. The resulting points have a Cauchy distribution. If you tried to figure out where the spinner was along the line by taking the arithmetic mean of the points, you would fail miserably. Taking the median is much more likely to give you a good answer. That was still a somewhat contrived example to demonstrate the point, but if you replace the spinner's pointing with photons, you realize that a Cauchy distribution describes the intensity of light shining on a flat surface from a point light source[2]. [1] That is, one of these things: http://www.ontrack-media.net/math8/m8m5l1image13.jpg http://www.ontrack-media.net/math8/m8m5l1image13.jpg [2] http://stats.stackexchange.com/a/36037/5736 http://stats.stackexchange.com/a/36037/5736