Archive | 2021
Energy in Thermal Physics
Abstract
The behavior of energy in bulk-matter systems is subtle. We observe that energy flows spontaneously from high to low temperature; we refer to this flowing energy as heat; and we distinguish heat from work, the transfer of energy through mechanical or other means unrelated to temperature. On the other hand, simple models of gases and solids strongly suggest that at the molecular level all energy is purely mechanical. This introductory chapter surveys these basic concepts of thermal physics, illustrates them with a wide variety of familiar examples, and sets the stage for developing a deeper understanding.