Danny McAndless was our Physics teacher when I was at the grammar school in the 1960’s.  He’d been someone’s Physics teacher at the grammar school since the 1860’s.

In one of the lessons he tried to explain to a bunch of bored 15 year-olds how the whereabouts of apparently random particles could be determined on the basis of probability by Brownian Motion.

Now I’m in my 70’s I wish I’d paid more attention than I did.  It would have come in handy trying to second-guess the haphazard meanderings of old gits on the cycle paths I peddle around.