Markov

 Starting off this post with a photo of Russian mathematician Andrey Markov(1856- 1922)

for the very simple reason that he was rather good-looking.

His area of interest was stochastic processes ( ones where randomness is involved); and he

is known for Markov chains, essentially the idea that, as the Russian-language Wikipedia entry put it -

the past does not influence the future. Below, a Markov chain with probabilities attached for

each one-step alternative:

                                                           *     *     *

Nothing terribly surprising in this model. Starting on a 50/50 chance of rainor sun, each

run prints out a plausible sequence...

                                                            *     *     *

The second model introduces a bit of a twist: it is the probability of sun followed by rain

that is given! A camera captures whether emploees are entering the building with an umbrella.

I ran number 2 a number of times, and the results are always the same.