We like to think of particles as tiny little balls of stuff. That works for lots of thought experiments even though particles aren’t little balls. Not even a little bit. According to quantum mechanics, they are superbizarre little fluctuations in fields that permeate the entire universe. That means they obey rules that make very little sense in the tiny-little-ball model. For example, they can be on one side of an impenetrable barrier one moment and then appear on the other side the next—without passing through the barrier.34 Quantum particles can do things that seem to make no sense if you
...more
