Ferminferiority

Another cartoon from xkcd here.

While the concept is amusing, I can't decide whether it's his suggested X(f) or X(d) value that more efficiently makes me feel old, damned old. (I know, I should probably ask my wife.) Mind you, Edinburgh's population density is only about a quarter of his suggested figure so perhaps they're wrong to a similar degree.......

....which doesn't make me feel quite as ancient. Still, I am 1.45 times the average age of people in Edinburgh.