I've been very interested in this topic for a long time, but I found this article to be difficult to read. "planetary" vs "planetarity" confused me, for example

I've been very interested in this topic for a long time, but I found this article to be difficult to read. "planetary" vs "planetarity" confused me, for example. Can anyone here recommend related articles on planet-scale intelligence? Have you read any of the author's books? "The Stack" sounds interesting.