(right). The same phenomenon is observed as appearing differently.]] A phenomenon (from Greek φαινόμενoν, pl. φαινόμενα - phenomena) is any observable occurrence. In popular usage, a phenomenon often refers to an extraordinary event. In scientific usage, a phenomenon is any event that's observable, however commonplace it might be, even if it requires the use of instrumentation to observe it. For example, I… (More on Phenomenon)