A Dialogue on Position
Keywords: position
A student who wants to "understand" quantum mechanics asks a physics professor how to determine the four-coordinate position of a particle. It soon becomes evident that Heisenberg's microscope experiment is totally inadequate as a model since the observer does not actually participate in the measurement process, and a procedure for measuring the time coordinate microscopically has never been defined. In fact, in a strict sense, quantum mechanics does not have a logically coherent method for determining position in even a single dimension. Their attempts to resolve these differences are an exercise in futility until the student finally realizes that before they can agree on anything they have to be able to communicate.
