Karl Pearson introduced the term "Random Walk". He was interested in describing the spatial/temporal evolutions of mosquito populations invading cleared jungle regions. He found it too complex to model deterministically, so he conceptualized a simple random model.
Pearson posed his problem in Nature (27 July 1905):
A man starts from a point 0 and walks l yards in a straight line; he then turns through any angle whatever and walks another l yards in a second straight line. He repeats this process n times. I require the probability that after n of these stretches he is at a distance between r and r 'r from his starting point.
"A drunk man will find his way home, but a drunk bird may get lost forever"
randomWalks
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