You might need to lie down for a bit after “Eddington.” Preferably in a dark room with no screens and no talking. “Eddington,” Ari Aster’s latest nightmare vision, is sure to divide (along which lines, I can’t fathom) but there is one thing I think everyone will be able to agree on: It is an experience that will leave you asking, “WHAT?” The movie opens on the aggravated ramblings of an unhoused man and doesn’t get much more coherent from there...