Heat transfer physics Heat transfer physics Heat transfer physics describes the kinetics of energy storage, transport, and energy transformation by principal energy carriers: phonons (lattice vibration waves), electrons, fluid particles, and photons. Heat is energy stored in temperature-dependent motion of particles including electrons, atomic nuclei, individual atoms, and molecules. Heat is transferred to and from matter by the principal energy carriers. The state of energy stored within matter, or transported by the carriers, is described by a combination of classical and quantum statistical mechanics. The energy is also transformed (converted) among various carriers. The heat transfer processes (or kinetics) are governed by the
Evaporative cooling (atomic physics) Evaporative cooling (atomic physics) Evaporative cooling is an atomic physics technique to achieve high phase space densities which optical cooling techniques typically can not reach. Atoms trapped in optical or magnetic traps are cooled as the trap depth is decreased and the hottest atoms (with the highest kinetic energy) leave the trap. The hot atoms leaving the trap are on the tail of the Maxwell-Boltzmann distribution and therefore carry away a significant amount of kinetic energy, mitigating the loss of atoms by an overall increase in phase space density. The technique is analogous to cooling a hot cup of coffee