Somehow a Supermassive Black Hole can flip its Magnetic Field

There is a running joke in astronomy that pretty much any talk can be thwarted by the simple question: What are the effects of a magnetic field?

I’ve known that joke my whole career, and in my own research have even had some answers on hand if needed. But… I’m not going to lie… magnetic fields are one of those things I totally understand at the undergraduate level, but when it comes to understanding what is happening on even planet-sized scales, I — an observational astronomer — am content to quote the basic idea that “there…