When thinking about steam engines, it never occurred to anyone that this fact had any significance. Who cares that you can’t be 100% wasteful with your precious, precious coal? But it has enormous significance for the emergence of life, because it says that energy flows through a system must, to some extent, organize that system. The first book to my knowledge to explicitly treat this topic was Harold Morowitz’s “Energy Flow in Biology.” One slightly subtle point that people often miss: it is not energy per se that organizes a system, but energy flow. Life occurs between a source and a sink, and what it requires is not any absolute amount of energy but an energy difference which we call a gradient. It is the energy gradient that causes the spontaneous flow of energy from the source to the sink, and it is the existence of the flow that is the source of the organization. Or rather, a directed flow is an organization. Might not be much of an organization compared to the circulatory and nervous systems, but a river is, in this sense, “organized.” It is obvious that the water molecules in a river are not moving randomly with respect to one another but are moving together in response to the direction of the flow. The flow is occurring as a way of dissipating gravitational potential. This idea was mathematically formalized by Ilya Prigogine with the concept of a dissipative structure. So another way of saying that life is a non-equilibrium organization is to say that organisms are a class of dissipative structures.