Heat may be generated and destroyed by certain processes, and this sho — Thermodynamics

"In order to consider in the most general way the principle of the production of motion by heat, it must be considered independently of any mechanism or any particular agent. It is necessary to establish principles applicable not only to steam engines but to all imaginable heat-engines, whatever the working substance and whatever the method by which it is operated."

"If the Krebs cycle is ordained by thermodynamics, then it should take place spontaneously in some suitably propitious envirnonment, even in the absence of s."

"The second closed system of concepts was formed in the... nineteenth century... with the theory of heat. Though the theory... could finally be connected with mechanics through... statistical mechanics, it... [was not] a part of mechanics. ...[T]he phenomenological theory of heat uses... concepts that have no counterpart in other branches of physics, like: , specific heat, entropy, free energy, etc. If... one goes... to a statistical interpretation... considering heat as energy, distributed statistically among... many degrees of freedom due to... atomic structure of matter, then heat is no more connected with mechanics than with electrodynamics or other parts of physics. The central concept... is... probability, closely connected with the concept of entropy... [T]he statistical theory of heat requires the concept of energy. But any coherent set of axioms and concepts in physics will necessarily contain the concepts of energy, and and the law that these ...must under certain conditions be conserved. This follows if the coherent set is intended to describe... features of nature... correct at all times and everywhere... [i.e.,] features that do not depend on space and time... [i.e.,] that are invariant under arbitrary translations in space and time, s in space and the Galileo or . Therefore, the theory of heat can be combined with any of the other closed systems of concepts."

"[I]n the nineteenth century, even the could be reduced to mechanics by the assumption that heat really consists of a complicated statistical motion of the smallest parts of matter. By combining the concepts of the mathematical theory of probability with the concepts of Newtonian mechanics Clausius, Gibbs and Boltzmann were able to show that the fundamental laws in the theory of heat could be interpreted as statistical laws following from Newtons mechanics when applied to very complicated mechanical systems."

"The whole science of heat is founded Thermometry and Calorimetry, and when these operations are understood we may proceed to the third step, which is the investigation of those relations between the thermal and the mechanical properties of substances which form the subject of Thermodynamics. The whole of this part of the subject depends on the consideration of the Intrinsic Energy of a system of bodies, as depending on the temperature and physical state, as well as the form, motion, and relative position of these bodies. Of this energy, however, only a part is available for the purpose of producing mechanical work, and though the energy itself is indestructible, the available part is liable to diminution by the action of certain natural processes, such as conduction and radiation of heat, friction, and viscosity. These processes, by which energy is rendered unavailable as a source of work, are classed together under the name of the Dissipation of Energy."

"Newton and his theories were a step ahead of the technologies that would define his age. Thermodynamics, the grand theoretical vision of the nineteenth century, operated in the other direction with practice leading theory. The sweeping concepts of energy, heat, work and entropy, which thermodynamics (and its later form, statistical mechanics) would embrace, began first on the shop floor. Originally the domain of engineers, thermodynamics emerged from their engagement with machines. Only later did this study of heat and its transformation rise to the heights of abstract physics and, finally, to a new cosmological vision."