Negentropy has also been called: negative entropy, syntropy,
extropy or entaxy.
The negentropy of a living system is the entropy that it exports
to keep its own entropy low. It lies at the intersection of
entropy and life. Negentropy has been used by biologists as the
basis for purpose or direction in life, namely cooperative or
The concept and phrase "negative entropy" were introduced by
Erwin Schrödinger in his 1944 popular-science book 'What is
Life?'. Later, Léon Brillouin shortened the phrase to negentropy,
to express it in a more "positive" way of resoning: a living
system imports negentropy and stores it. In 1974, Albert
Szent-Györgyi proposed replacing the term negentropy with
syntropy. That term may have originated in the 1940s with the
Italian mathematician Luigi Fantappiè, who tried to construct a
unified theory of biology and physics. Buckminster Fuller tried
to popularize this usage, but negentropy remains common.
In 2009, Mahulikar & Herwig redefined negentropy of a
dynamically ordered sub-system as the specific entropy deficit of
the ordered sub-system relative to its surrounding chaos. Thus,
negentropy has units [J/kg-K] when defined based on specific
entropy per unit mass, and [K−1] when defined based on specific
entropy per unit energy. This definition enabled: i)
scale-invariant thermodynamic representation of dynamic order
existence, ii) formulation of physical principles exclusively for
dynamic order existence and evolution, and iii) mathematical
interpretation of Schrödinger's negentropy debt.
The term Negentropy is not only used in physics and biology, but
also in other domains, such as Information Theory, Statistics,
Organization management, though with a slightly different
meaning, for example: In Risk Management, negentropy is the force
that seeks to achieve effective organizational behavior and lead
to a steady predictable state.
Extropy is a concept that life will continue to expand throughout
the universe as a result of human intelligence and technology.