Arthur C. Clarke Quote
The universe is full of energy, but much of it is at equilibrium. At equilibrium no energy can flow, and therefore it cannot be used for work, any more than the level waters of a pond can be used to drive a water-wheel. It is on the flow of energy out of equilibrium—the small fraction of useful energy, exergy—that life depends.
Arthur C. Clarke
The universe is full of energy, but much of it is at equilibrium. At equilibrium no energy can flow, and therefore it cannot be used for work, any more than the level waters of a pond can be used to drive a water-wheel. It is on the flow of energy out of equilibrium—the small fraction of useful energy, exergy—that life depends.