Ersatz Physics: a tribute to Jessica Hagy's Indexed and the humor of Demetri Martin.
Suggestions are welcome.
Another explanation - this refers to the lack of hiring of new faculty. Average age increases by 1 year every year coz they haven't hired anyone new and no one's retiring. Some countries have mandatory retirement. Personally, I don't mind having the geezers still around, but I wish we could get rid of the ones who just come in to nap and read the paper.