Today is ‘Tell an Old Joke Day’.

It is also the day we commemorate the death of Sir James Chadwick (20 Oct 1891 – 24 Jul 1974), who was awarded the 1935 Nobel Prize for Physics for the discovery of the neutron.

So I guess my old joke for this special day kind of selects itself…

A neutron walks into a bar and orders a whisky.
The bartender pours him a stiff one.
“How much do I owe you?”, the neutron asks.
“For you?” replies the bartender, “no charge!”