ABSTRACT
Fundamentally, energy and the absolute temperature, measured in Kelvins [K] (not °K!), are related only by a scale factor, known as Boltzmann’s constant (k) after its discoverer (k = 8.617 × 10−5 eV/K) such that energy (E) (eV) = kT [K]. Hence, temperature is just a different measure of energy; they are fundamentally the same thing. (The physics underlying temperature is explored in more detail in Chapter 7.) The “thermal energy” (kT), as it is known, figures prominently in the physics of micro/nanoscale systems. At “room temperature” (300.00 K = 26.85°C = 80.33°F), for instance, the thermal energy is a miniscule 0.0259 eV. By any reckoning, kT is the most fundamental parameter of the universe, because it governs the behavior of both the Fermi–Dirac and Bose–Einstein distribution functions, which control the behavior and structure of all particles and hence matter in the universe.
