English

Noun

disgregation ‎(uncountable)

1. Separation; scattering.
2. (thermodynamics) Entropy, defined as the magnitude of the separation of the particles of a system. Introduced by the German physicist Rudolf Clausius in 1862.

If we examine the conditions under which heat can be transformed into ergon, and, conversely, ergon into heat, we find, in the first place, that the commonest and simplest process is the following. The heat which exists in material bodies tends to alter their condition. It tends to expand them, to render solid bodies liquid and gaseous, and, as we may likewise add, to resolve chemical compounds into their elements. In all these cases the effect of the heat consists in loosening or completely dissolving the connexion which exists between the molecules or atoms, and in separating to the greatest possible distance such molecules as are already completely disconnected from each other.

In order to be able to express this action shortly, I have introduced a magnitude which denotes the extent to which this separation and parting of its smallest particles, which it is the tendency of heat to effect, has already been carried in the case of any body. This magnitude I call the Disgregation of the body. The disgregation of a body is consequently, among the three states of aggregation, least in the solid state, greater in the liquid state, and greatest of all in the gaseous state. In the last condition it can still be increased by the molecules separating further from each other—that is, by the gas expanding to a larger volume. In like manner, the decomposition of a chemically compound body into its elements is in general accompanied by an increase of disgregation.

By help of this conception the effect of heat can be simply expressed by saying that heat tends to increase the disgregation of bodies.^[1]

Antonyms

• aggregation
• congregation

References

1. ↑ Clausius, R. ♦ On the Second Fundamental Theorem of the Mechanical Theory of Heat A lecture delivered before the forty-first meeting of the German Scientific Association, at Frankfurt on the Maine, September 23, 1867 ♦ The Philosophical Magazine and Journal of Science, June 1868, pp. 407–08