negative entropy

The concept of "negative entropy," often referred to as negentropy, is closely linked to information theory and thermodynamics. In essence, it describes a process that decreases entropy, thereby increasing order within a system.

Entropy, a concept from thermodynamics, originally introduced by Rudolf Clausius, measures the disorder or randomness in a system. The second law of thermodynamics states that in an isolated system, entropy tends to increase over time, meaning systems naturally move towards disorder unless energy is introduced.

Information theory, pioneered by Claude Shannon, uses mathematical tools to analyze communication systems, including how to handle "noise" which is an inherent part of the universe. Shannon's work shows that transmitting information requires energy and that noise, like thermal noise or cosmic background radiation, is unavoidable.

James Clerk Maxwell's thought experiment involving "Maxwell's demon" explored a hypothetical being that could seemingly violate the second law of thermodynamics by sorting molecules to create order without external energy input. However, information theory demonstrates that the demon's act of gathering information requires energy, thus upholding the second law. Negentropy, therefore, is the measure of this decrease in entropy, representing an increase in order or information within a system, often at the cost of energy expenditure.12