Magnetic Fields.

Astrophysics Magnetic field shapes spinning black hole. The astrophysicist in his home territory:

"At the time of our interview, McKinney was working in a small office on the fourth floor of the physics building of the University of Maryland. He had just moved and his office had boxes everywhere, a bicycle shoved into a corner and two tables awkwardly positioned in the middle of the room. The tables were coated with a layer of black soot that had dropped through a ceiling air vent.

"My own jet of grossness," he called it."