On the research program behind the pinball machine, or the more dignified name it went by, “Random Mechanical Cascade.” Here, described is Francis Galton’s “Law of the Frequency of Error,” a recurring pattern behind an early demonstration:
For reasons that are a little tricky to explain, a great deal of the stuff in the universe can be characterized using this curve. For example: if I measure the length of Manhattan many times using a ruler, I will come up with a mess of slightly different values; plotted, they will distribute themselves in one of these normal curves (with the odds being that my best answer will lie at the mean). Similarly, if I make everyone in Manhattan take an IQ test, their results, too, will fall out in a normal distribution. Ditto a host of other traits of this population, and, moreover, of all the other populations on the island, from the roaches to the seagulls.