For the scientific discussion of entropy, see entropy: second law of thermodynamics.
For Robert Smithson, architecture depends on the repression of entropy.
"The dream of architecture is to escape from entropy."(Informe: Mode d'Emploi )
In the late nineteenth century speculation about entropy intersected with the culture of colonialism, with the uneasy relations between technological progress (primarily through the heat engine) and a sense of cultural pessimism. Thus for Oswald Spengler, entropy "signifies today the world's end as a completion of an inwardly necessary relation." (see Crosbie Smith and Norton Wise, Energy and Empire )
In 1852 William Thompson, Lord Kelvin, predicted the death of the earth from heat loss in an article entitled "On a Universal Tendency in Nature to the Dissipation of Mechanical Energy." In it he wrote that "There is at present in the material world a universal tendency to the dissipation of mechanical energy. Any restoration of mechanical energy, without more than an equivalent amount of dissipation, is impossible...and is probably never effected by means of organized matter, either endowed with vegetable life or subjected to the will of an animated creature." "Within a finite period of time...the earth must again be unfit for the habitation of man as present constituted." (quoted and commented upon in Hayles, Chaos Bound, pp 39-42)
In his own interpretation of entropy, James Clerk Maxwell drew attention to the relation between the disorder of dissipated energy and the confusion of the perceiving subject. "The idea of dissipation of energy depends on the extent of our knowledge," Maxwell said. (Quoted in Glieck, The Information, p.272.) "Available energy is energy which we can direct into any desired channel. Dissipated energy is energy we cannot lay hold of and direct at pleasure..." From this observation, Maxwell imagined a "very observant and neat-fingered being" who could lay hold of dissipated energy at the microscale. In his famous letter to P.G. Tait of 1867, he imagined "a finite being who knows the paths and velocities of all the molecules by simple inspection but can do no work except open and close a hole...by means of a slide without mass. "
"Maxwell's demon", as Thomson dubbed him, would take on a life of his own, and would later preside over the gateway from the world of physics to the world of information.
Maxwell conceived of a box in which gas starts out in the equilibrium macrostate, with a demon to operate a valve, putting the faster moving molecules on one side and the slower on the other. Ostensibly without doing work, the demon would allow temperature and pressure to build up on one side of the box in relation to the other, thus allowing work to result. "the hot system has gotten hotter and the cold colder and yet no work has been done, only the intelligence of a very observant and neat-fingered being has been employed. " Yet this new state, with its macroscopic temperature difference between the two boxes, could be used to extract mechanical work.
In 1929, Leo Szilard showed that for a "biological system" or even a non-living device, the Demon would have to perform work in the process of measurement. Although he did not yet use the word information, Szilard calculated the energy required for the measurement and memory of each choice between particles. This was equal to the energy gained by the corresponding decrease in entropy (which would later be known as a bit). Thus measurement of an equilbrium system takes exactly as much work as the the work that the measurement may yield.
From the beginning, it was thought that living organisms were a possible exemption from the Second Law. Kelvin referred to the power of the will in his 1852 essay entitled "On the Power of Animated Creatures over Matter" and suggested that "the animal body does not act as a thermo-dynamic engine." (cf Stuart Kauffman "order for free")
Erwin Schrödinger in his book What is Life? considered life, which is highly improbable, to be the inverse of S, which he called negentropy. He saw in the chromosomes, the "code script" that contained the pattern of an individual's development and its functioning in the mature state. (see genotype / phenotype) Thus natural selection becomes the "work" that achieves and maintains order in systems whose internal disorder would otherwise increase. For Schrödinger, an organism feeds on negative entropy.
Pure statistical improbability is not a sufficient description of living organisms, however. As André Lwoff pointed out, "The living organism is not only an improbable system but a system fitted for certain functions." The functional order of biology cannot be measured by its improbability. Indeed, its probability has assumed greater importance in contemporary accounts of the beginnings of life -- eg. Stuart Kaufman.
James Clerk Maxwell pointed to a third state, neither entropy nor evolution, but stability. For Maxwell, molecules have a specially durable structure, "incapable of growth or decay, of generation or destruction." (quoted in E. Fox Keller, Refiguring Life, p.52) While Maxwell's demon resembles the kind of divine intelligence that Laplace invoked. He has a more human quality, and is especially important as a guardian of free will. He is a sort of "ghost in the machine," and has been compared to a railway switchman, sending the express on one line and the goods along another. Stuart Kauffman compares Maxwell's "demon" to his own concept of an "autonomous agent."
Stuart Kauffman suggests that a "weak" Maxwell's Demon can be thought of as analogue to natural selection. He focuses on the "back pressure" that builds up on the valve, and that a weak Demon would only be able to slightly change the pressure between the two chambers. The equilbrium attractor would thus resist and limit his efforts.
Continuing his interpretations of Maxwell's demon in Investigations, Kauffmann compares the progressive emergence of organization in the physical universe and in a biosphere with the measurements made by Maxwell's demon. A biosphere is filled with entities that find and measure useful displacements from equilibrium from which work can be extracted. These entities construct constraints on and couplings to the release of the identified source of energy that can perform work. Such work often comes to be used to construct further detectors of energy sources that in turn...(pp 82-3)
But the universe is not in equilibrium. It is possible to obtain more work out of measuring a non-equilibrium system than the work that the measurement itself requires, as long as the measurement is a "useful" one -- a measurement which identifies those features of a given non-equilibrium system which can be coupled to a work-extracting structure.