Zipf’s Law
I’d heard of Zipf’s Law before, but was still astonished when a friend sent me this New York Times article about some of the things it applies to. The parts of it that really got me:
[T]he largest city is always about twice as big as the second largest, and three times as big as the third largest, and so on. In other words, the population of a city is, to a good approximation, inversely proportional to its rank. Why this should be true, no one knows.
—“Guest Column: Math and the City”, Steven Strogatz, The New York Times, 19 May 2009