The popular meaning of entropy as irreversible decay derives from its special meanings in the fields of physics and cybernetics. The Second Law of Thermodynamics states that differences in temperatures tend to equalize over time. This is the evolutionary path of the universe and is accompanied by the degradation and dissipation of matter and energy. Entropy operating at the cosmic scale, therefore, implies a movement towards an ultimate and universal state of uniformity and maximum chaos, characterized by an absence of form, pattern or order. When applied to more limited and human-scale systems, entropy implies a decrease in asymmetry (difference) and a movement towards inert homogeneity. There is a sense of levelling, erosion of variation and loss of distinctiveness. Human effort is required to work against the drag of entropy.
From cybernetics derives the meaning of entropy as the tendency of any closed system, for example an organization, to move from a less to a more probable (unstable) state, from order to disorder. Open systems, which appear to contradict entropy by not disintegrating strictly according to physical laws, take in energy and materials from their environment. Many have a property we call "life". But even living systems can only hold back the inevitability of ultimate death and decomposition.