Rory wrote to me about the asymmetry beer-wine and the choices made for parties: “Once you have ten percent or more women at a party, you cannot serve only beer. But most men will drink wine. So you only need one set of glasses if you serve only wine — the universal donor, to use the language of blood groups.”
The method of analysis employed here is called renormalization group, a powerful apparatus in mathematical physics that allows us to see how things scale up (or down). Let us examine it next –without mathematics.