A topic we should talk about was shaping up in my brain. Then, this morning, I read Paul Krugman's review [link] of Robert Gordon's new book. I saw that Gordon already did much of the work for my new topic. Gordon presents good evidence that between 1870 and 1970 there were super improvements in living standards not seen before nor since.
He says that this was the result of several "great inventions" and lists: electricity, urban sanitation, chemicals and pharmaceuticals, the internal combustion engine, modern communication. All of these depend on electromagnetism. The giant leap in communication came at the beginning of his period with the Atlantic submarine telegraph cable.
The internal combustion engine needs an electromagnetic generator for the sparks causing the combustion. Urban sanitation needs electric pumps to raise water above tall buildings. It hurts my brain to try to imagine chemical and pharmaceutical industries relying on steam engines rather than electrimagnetic pumps.