How would you explain the difference between heat, thermal energy and temperature to someone who did not know?
I’ll assume that the person unfamiliar with these concepts *is* aware of the fact that all matter is made up of particles (i.e., atoms), and that there is a quantity called “energy” that is a measure of the capacity of a physical system to do work (or more generally, to effect a change on another physical system). Energy comes in different forms, and can be divided into two general categories: kinetic energy, which is energy associated with motion; and potential energy, which is energy associated with the position or configuration of a system. The “thermal energy” of a system is simply the sum of the kinetic energies of all the particles that compose that system. For example, the atoms in a solid are constantly oscillating back and forth about an average position. The fact that the atoms are moving means that they have kinetic energy, and the thermal energy is the sum of all those kinetic energies. Thermal energy makes up part of the internal energy of a system; the other part of the i
