In quantum mechanics, particles like electrons are also waves, and their behavior can be explained in part by the Schrodinger wave equation, or "the wavefunction." On this view, the electron is nothing like a tiny speck orbiting the nucleus. In fact, there’s no way to know where the electron is at any given time, because the electron is really just a "cloud" of probability—a fuzzy region where the electron might be. If you hold a hydrogen atom in your hand, there’s a pretty good probability that the electron is located at about .40 Angstroms from the nucleus. There’s also a very small but nevertheless very real probability that the electron is somewhere on Mars. The picture of a hydrogen atom that we get from quantum mechanics is of a slightly fuzzy sphere of probability for the position of the proton surrounded by a considerably more fuzzy sphere of probability for the position of the electron.