From HomoExcelsior

AKA Poisson Distribution, Poisson process

Named for S. D. Poisson, French mathematician d. 1840: Poisson was hired by the Prussian army to examine the alarming number of fatalities suffered by officers after being kicked by their horses. Poisson discovered a process where random independent events occuring through time are not likely to be evenly distibuted; in fact, the time between successive events follows what is called an exponential distribution, the most likely value of which is zero (or arbitrarily close to zero).

This means you're more likely to find rare events occuring rapidly one after another, and then nothing on the timeline for a long while, and then another clump, and so on.

This process may be in operation if we start to see a few more planes falling from the sky.

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