I came across this article on the most underrated inventions in history. It was kind of interesting to see how concrete changed the world. But the authors sometimes extrapolated a little too much. Horse collars allowed a farmer surplus which allowed an Adam Smith’s type professional stratification which destroyed the feudal system and allowed for the industrial age? I’m sure there are a few extra inventions and political events in there that allowed that sequence to progress. It’s still interesting though.

By the way, this is my first aside, a la crazymonk.