Power, energy, light, vibrations. These concepts can imply a flow, movement, influence, making something happen or change. Dark becomes light, we move from one place to another, music is created, Messages travel from person A to person B, hot places get cooled, tasks are accomplished. Legislation is passed, millions of people are persuaded to buy things, spacecraft visit Pluto. Each of these things requires power of a particular kind. Power can be understood in physical, social, political, economic, psychological, and metaphysical terms.