This animation represents a hydrogen atom’s single electron undergoing energy transformations. In this sequence light (energy) enters the atom from outside and transfers the electron’s matter-wave orbit to a higher energy state, moving it from shell to shell. The light is again expelled and the electron falls to a lower energy level. Incoming light expands the atom. Outgoing energy contracts the atom, a process analogous to breathing in and breathing out.
Animation by Ken Snelson & Jon Monaghan