| It may be admitted that on repeated measurement of those conjugate intensive functions of state, they are found to have slightly different values from time to time. Such variability is regarded as due to internal fluctuations. The different measured values average to their nominal values. | | It may be admitted that on repeated measurement of those conjugate intensive functions of state, they are found to have slightly different values from time to time. Such variability is regarded as due to internal fluctuations. The different measured values average to their nominal values. |
| When a body of material starts from a non-equilibrium state of inhomogeneity or chemical non-equilibrium, and is then isolated, it spontaneously evolves towards its own internal state of thermodynamic equilibrium. It is not necessary that all aspects of internal thermodynamic equilibrium be reached simultaneously; some can be established before others. For example, in many cases of such evolution, internal mechanical equilibrium is established much more rapidly than the other aspects of the eventual thermodynamic equilibrium.<ref name="Fitts 43">Fitts, D.D. (1962), p. 43.</ref> Another example is that, in many cases of such evolution, thermal equilibrium is reached much more rapidly than chemical equilibrium.<ref>Denbigh, K.G. (1951), p. 42.</ref> | | When a body of material starts from a non-equilibrium state of inhomogeneity or chemical non-equilibrium, and is then isolated, it spontaneously evolves towards its own internal state of thermodynamic equilibrium. It is not necessary that all aspects of internal thermodynamic equilibrium be reached simultaneously; some can be established before others. For example, in many cases of such evolution, internal mechanical equilibrium is established much more rapidly than the other aspects of the eventual thermodynamic equilibrium.<ref name="Fitts 43">Fitts, D.D. (1962), p. 43.</ref> Another example is that, in many cases of such evolution, thermal equilibrium is reached much more rapidly than chemical equilibrium.<ref>Denbigh, K.G. (1951), p. 42.</ref> |