Entropy, represented by the second law of thermodynamics is the slow, irreversible process of breakdown and decay.
Because of entropy, N-Space, the main universe, had a finite lifespan and would have "died" some time prior to the 20th century had the Logopolitans had not siphoned entropy out from it into E-Space, another universe via the CVE's which they created (DW: Logopolis, NA: Timewyrm: Apocalypse)
In N-Space and in E-Space, the entropy appeared as a green tint seen both in the sky of planets and in space itself. (DW: Full Circle, State of Decay) In 1981, the Master interfered with the Logopolitans and closed CVEs. A wave of entropy destroyed most of the universe. On the planet [[Logopolis (planet)|homeworld of the Logopolitans], machines affected by entropy would cease to function and then crumble. Parts of the Monitor, the Logopolitan leader, dissapeared unevenly, piece by piece and then he vanished. Whole stars and galaxies and most of the universe vanished, such as the Traken Union. (DW: Logopolis)
