Yeah, I believe he proved a correspondence between the arrows and the Schroedinger equation (not in that book) at some point (and it's not hard to come up with

Yeah, I believe he proved a correspondence between the arrows and the Schroedinger equation (not in that book) at some point (and it's not hard to come up with a character of the proof). The grandparent is referring to something like this video, though, which you mentioned at the end: http://www.youtube.com/watch?v=wMFPe-DwULM http://www.youtube.com/watch?v=wMFPe-DwULM Bringing in arrows where they don't belong, or in the magnet case "rubber bands", is cheating the asker. I'm not familiar enough with GR to know if arrows are a useful representation like they are with complex amplitudes.