ENTROPY SYSTEMS THEORY Kenneth

Entropy is a concept that was derived in the nineteenth century during the study of thermodynamic systems. Entropy exists in all systems, nonliving and living, that possess free energy for doing work. As system energy declines, entropy increases. Entropy has precise mathematical and statistical definitions, but can be approximately defined as the degree of disorder or uncertainty in a system. If a system is isolated, or cut off from all inputs of matter and energy, it will tend toward a maximum, according to the Second Law of Thermodynamics. Entropy is important for the study of life support systems because it offers a valuable way of defining and measuring sustainable systems. A sustainable system must, by definition, ensure that its entropy level does not rise to the maximum, as maximum entropy is tantamount to system death. To be sustainable, the system must have life support subsystems that can ensure supplies of matter, free energy, and information sufficient to maintain entropy levels below the maximum.