In physics, thermodynamics (from the Greek θερμη, therme, meaning “heat” and δυναμις, dynamis, meaning “power”) is the study of the conversion of heat energy into different forms of energy (in particular, mechanical, chemical, and electrical energy); different energy conversions into heat energy; and its relation to macroscopic variables such as temperature, pressure, and volume. Its underpinnings, based upon statistical predictions of the collective motion of particles from their microscopic behavior, is the field of statistical thermodynamics, a branch of statistical mechanics. Roughly, heat means “energy in transit” and dynamics relates to “movement”; thus, in essence thermodynamics studies the movement of energy and how energy instills movement. Historically, thermodynamics developed out of need to increase the efficiency of early steam engines. Typical thermodynamic system, showing input from a heat source (boiler) on the left and output to a heat sink (condenser) on the right. Work is extracted, in this case by a series of pistons.

The starting point for most thermodynamic considerations are the laws of thermodynamics, which postulate that energy can be exchanged between physical systems as heat or work. They also postulate the existence of a quantity named entropy, which can be defined for any system. In thermodynamics, interactions between large ensembles of objects are studied and categorized. Central to this are the concepts of system and surroundings. A system is composed of particles, whose average motions define its properties, which in turn are related to one another through equations of state. Properties can be combined to express internal energy and thermodynamic potentials, which are useful for determining conditions for equilibrium and spontaneous processes.

With these tools, thermodynamics describes how systems respond to changes in their surroundings.

From Wikipedia.

When the Ontic Principle, Latour’s Principle, the Principle of Irreduction, and the Hegemonic Fallacy are taken together, they can be understood as making the case for the introduction of something like thermodynamics into ontology. The Ontic Principle states that there is no difference that does not make a difference. Latour’s Principle states that there is no transportation without translation. The Principle of Irreduction states that nothing is either reducible or irreducible to anything else. And finally the Hegemonic Fallacy states that it is illicit to reduce all difference to one difference that makes all the difference or one difference that makes the most important difference. While the thermodynamic dimension of the Ontic Principle does not exhaust the signification of this principle, it nonetheless captures one important aspect that follows from this principle. Insofar as, ontologically, there is no difference that does not make a difference, it follows that difference requires work both for the entity making the difference and the entity upon which the difference is made. Both of these differences are involved in the interactive process of those objectiles entering into an assemblage with one another.