I have received an unwelcome sign of my maturing 50+ness. The first hair of many has sprouted from my left ear. I can now look forward to the day when my ears are hairier than my goatee... Sigh.

Speaking of visual feedback loops, I'm reminded of my college days, having fun aiming a video camera (before the days of even personal video recorders, when there were even still vacuum tubes here and there still in use) at a monitor, and watching the "trippy" infinite regression image that resulted.