(No, this post is not about sex…sorry. Nor is it about electrical engineering, though it might at first give that impression.)
The often-interesting General Electric blog has an article about drones, linked to a cloud-based AI platform, which are used to inspect power lines and detect incipient problems–for example, vegetation which is threatening to encroach on the lines and short them out, or a transformer with a tendency to overheat. The article mentions a 2003 event in which an encounter between an overgrown tree branch and a sagging power line resulted in a wide-area blackout that affected 50 million people.
The inspection drone sounds like a very useful and productivity-improving tool: obviously, inspecting thousands of miles of power lines is nontrivial job. But the deeper issue, IMO, is the fact that one problem in one place can propagate over such a wide area and affect such a vast number of people. Power system designers and the people who operate these systems are certainly aware of the need to minimize fault propagation: circuit breakers and fuses, network analysis tools, and the technologies of protective relaying were developed, by GE among others, precisely for reasons of fault localization. But experience shows that large-scale fault propagation still sometimes does take place.
This problem is not limited to electrical systems. The mention of the tree-branch-caused 2003 blackout reminded me of a passage from the historian Hendrik Willem Van Loon:
Unfortunately in the year 1914 the whole world was one large international workshop. A strike in the Argentine was apt to cause suffering in Berlin. A raise in the price of certain raw materials in London might spell disaster to tens of thousands of long-suffering Chinese coolies who had never even heard of the existence of the big city on the Thames. The invention of some obscure Privat-Dozent in a third-rate German university would often force dozens of Chilean banks to close their doors, while bad management on the part of an old commercial house in Gothenburg might deprive hundreds of little boys and girls in Australia of a chance to go to college.
This probably overstates the interconnectedness of the global economy as it existed in 1914, but would fit our present-day global economy very well. (The author was talking about the origins of WWI, which he blamed largely on economic interconnectedness…not correct, IMO, but the war was largely caused, or at least reached the scale that it did, because of another type of interconnectedness…in the shape of alliances.)