patentNumber: "US-IMP-2,991,103" title: "Maxwell's Demon Refrigeration Unit" titleRu: "Холодильная установка с демоном Максвелла" filingDate: "June 19, 1923" issueDate: "December 7, 1927" inventor: "Prof. Wilhelm K. Strauss" inventorRu: "проф. Вильгельм К. Штраус" inventorSlug: "wilhelm-strauss" classification: "Thermodynamic Heresies" status: "Provisionally Impossible" abstract: "A refrigeration apparatus operating without consumption of external power, comprising a sealed gas-tight enclosure (1) partitioned into a colder chamber (2) and a warmer chamber (3) by an internal wall (4), said wall being pierced by a single small aperture (5) of dimension comparable to the mean free path of the working gas, said aperture being fitted with a friction-less shutter (6) operated by an intelligent agent (7) of microscopic dimensions which observes the velocity of each gas molecule approaching the aperture and opens the shutter to permit the passage of fast molecules from the colder chamber to the warmer, and slow molecules from the warmer chamber to the colder, while preventing the passage of all other molecules. The aggregate effect of said selective operation is to establish a temperature difference between the two chambers without the performance of work by any external agent." abstractRu: "Холодильный аппарат, работающий без потребления внешней энергии, состоящий из герметичного газонепроницаемого корпуса (1), разделённого внутренней стенкой (4) на холодную камеру (2) и тёплую камеру (3); указанная стенка прорезана единственным малым отверстием (5) размером порядка длины свободного пробега рабочего газа. Отверстие снабжено бесфрикционной заслонкой (6), управляемой разумным агентом (7) микроскопических размеров, который наблюдает скорость каждой молекулы газа, приближающейся к отверстию, и открывает заслонку для пропуска быстрых молекул из холодной камеры в тёплую и медленных молекул из тёплой камеры в холодную, препятствуя проходу всех прочих. Совокупное действие такой избирательной работы устанавливает разность температур между двумя камерами без совершения работы каким-либо внешним агентом." citations:

• "US-IMP-2,847,221"

Field of InventionОбласть изобретенияField of Invention

The present invention relates to apparatus for the production of refrigeration — that is, for the maintenance of one region of a system at a temperature lower than that of its surroundings — and more particularly to the production of such refrigeration without the consumption of fuel, electrical power, or other external energetic input. The invention is intended for application in the preservation of foodstuffs, the cooling of habitations during the summer months, and the cryogenic liquefaction of gases for industrial and laboratory purposes.

BackgroundПредпосылкиBackground

Refrigeration in the modern sense is conventionally accomplished by means of a vapor-compression cycle, wherein a working fluid is alternately compressed and expanded with the aid of a mechanical pump, the latent heat of vaporization being absorbed from the refrigerated region during expansion and rejected to the surroundings during compression. The cycle is convenient and reliable but presents the disadvantages of (a) requiring a continuous input of mechanical power to the pump, with attendant fuel costs; (b) emitting an audible hum throughout its operation; and (c) introducing into the modern household an apparatus of indifferent reliability requiring the seasonal attentions of a costly repairman.

The instant invention obviates each of these disadvantages by dispensing with the mechanical pump altogether and substituting in its place a microscopic agent of selective perception, of the kind first contemplated by Maxwell (1867) in his celebrated Theory of Heat. The agent — which the inventor here designates as a "demon," following the convention introduced by Lord Kelvin (1874) — is of dimensions sufficiently small that it may observe the individual molecules of the working gas; sufficiently fast that it may operate the shutter (6) within the duration of a single molecular transit; and of sufficient intelligence that it may distinguish a fast molecule from a slow one and exercise its judgment accordingly.

Summary of the InventionКраткое изложение изобретенияSummary of the Invention

The apparatus comprises:

• A sealed gas-tight enclosure (1) of brass or stainless steel construction, of nominal interior volume one cubic meter, charged to one atmosphere absolute with a working gas comprising nominally dry air or, in alternative embodiments, helium or argon;
• An internal wall (4) of asbestos-board construction, partitioning the enclosure into a colder chamber (2) of one-half cubic meter and a warmer chamber (3) of one-half cubic meter, the chambers being initially identical in temperature and composition;
• A single aperture (5) pierced through said internal wall, of nominal diameter one micrometer, comparable to the mean free path of the working gas at the design conditions;
• A friction-less shutter (6) covering said aperture, fabricated of a single sheet of aluminium foil and pivoted upon a sapphire bearing of negligible friction;
• An intelligent agent (7) of microscopic dimensions, resident in the immediate vicinity of the aperture, configured to observe the velocity of each gas molecule approaching the aperture and to operate the shutter accordingly;
• A pair of mercury thermometers (8), one in each chamber, by which the developing temperature difference may be observed by an external operator;
• A heat exchanger (9) coupled to the colder chamber, by which the refrigeration produced therein may be conveyed to such external use as may be desired (e.g., an icebox attached to the side of the enclosure);
• A food chamber (10), being a cavity within the cold side, of approximate volume sufficient for one gallon of milk and a quantity of cheeses.

U.S.B.I.P. Drawing №Чертёж У.С.Б.И.П. №U.S.B.I.P. Drawing №

Sheet 1 of 1Лист 1 из 1Sheet 1 of 1

Detailed DescriptionПодробное описаниеDetailed Description

Referring to FIG. 5A, the apparatus is shown in cross-section. The outer enclosure (1) is of welded brass construction, of internal dimension one meter cubed, fitted with a gas-tight access port for the introduction of the working gas and for the periodic relief of the agent.

The internal wall (4) is bonded gas-tight to the enclosure's interior and is centrally pierced by the aperture (5). The aperture is sufficiently small that, at the working pressure of one atmosphere, the rate of molecular transits through the aperture (in either direction, in the absence of intervention by the agent) is approximately 10¹⁰ per second, this rate being well within the operating bandwidth of the agent (see below).

The shutter (6) is mounted upon a sapphire bearing of friction coefficient not exceeding 10⁻⁶, and is operated by a fine linkage of human-hair-and-shellac construction extending from the pivot to the station of the agent (7). The shutter is configured to be normally closed; opening is effected only at the direction of the agent and only for the duration of one molecular transit.

The agent (7) is of dimensions approximately one micrometer in each linear extent and is of a constitution which the inventor has reserved as a trade secret, but which, upon information and belief, comprises a colony of Pseudomonas of unusually well-developed faculties, cultured in the inventor's laboratory through a process of selective breeding over a period of approximately twenty-five years. The agent is fed a diet of nutrient agar twice daily by means of a feeding tube extending through the enclosure's wall.

In normal operation, the agent observes the velocity of each gas molecule approaching the aperture from either side. Upon detection of (a) a molecule of speed greater than the root-mean-square thermal speed approaching from the cold side, the agent opens the shutter momentarily and permits the molecule to pass into the warm side; or (b) a molecule of speed less than the root-mean-square thermal speed approaching from the warm side, the agent likewise opens the shutter and permits the molecule to pass into the cold side. In all other cases, the agent withholds the shutter and the molecule is reflected without passage.

By this protocol of operation, the mean speed of molecules within the warm chamber is gradually increased and the mean speed within the cold chamber is gradually decreased, with the consequence that the temperature of the warm chamber rises and that of the cold chamber falls. The apparatus accordingly produces a temperature difference between the two chambers without the consumption of external power, and the cold chamber may be used to refrigerate such foodstuffs as may be deposited therein.

ClaimsФормула изобретенияClaims

1. A refrigeration apparatus comprising: a sealed enclosure; an internal partition dividing said enclosure into a first chamber and a second chamber; an aperture pierced through said partition; a shutter operatively coupled to said aperture; and an intelligent agent disposed in the vicinity of said aperture and configured to operate said shutter selectively in response to the velocity of gas molecules approaching said aperture.

2. The apparatus of claim 1, wherein said aperture is of nominal diameter not exceeding one micrometer.

3. The apparatus of claim 1, wherein said agent is configured to permit the passage of molecules of speed greater than the root-mean-square thermal speed from said first to said second chamber, and the passage of molecules of speed less than said speed from said second to said first chamber, and to prevent all other passages.

4. The apparatus of claim 1, wherein said agent comprises a culture of Pseudomonas of selectively-bred constitution.

5. The apparatus of claim 1, further comprising a pair of thermometers, one in each chamber, for the observation of the developing temperature difference.

6. The apparatus of claim 1, further comprising a heat exchanger coupled to one of said chambers for the application of the refrigeration produced therein.

7. A method for the production of refrigeration without consumption of external power, comprising the steps of: (a) charging the apparatus of claim 1 with a working gas; (b) instructing said agent in the protocol of operation; (c) supplying said agent with nutrient agar twice daily; and (d) waiting.

Why This Violates Physics (For Now)Почему это нарушает физику (пока)Why This Violates Physics (For Now)

The invention as claimed is, beyond reasonable dispute, provisionally impossible. It is the canonical example, in the philosophy of physics, of an apparatus which appears to violate the Second Law of Thermodynamics, and the analysis of its impossibility constitutes a significant portion of the foundational literature of statistical mechanics.

First, the apparatus as described produces a decrease in the entropy of an isolated system at no thermodynamic cost, the agent performing its selective operations without (according to the application) consuming any energy or producing any heat. The Second Law in the Clausius formulation holds that heat cannot of itself flow from a colder to a hotter body; the apparatus claims to perform precisely this operation through the agency of the demon. The Second Law in the Kelvin–Planck formulation holds that no cyclic process can convert heat entirely into work; the apparatus, by establishing a temperature difference from an initially uniform reservoir, creates precisely the conditions under which such conversion becomes possible. The apparatus therefore appears to permit the construction of a perpetual motion machine of the second kind, after the manner of U.S.-IMP-2,847,221.

Second, the resolution of this paradox has been the subject of investigation for nearly a century. The earliest serious analysis, by Szilard (1929), demonstrated that the measurement performed by the demon — the determination of each molecule's velocity prior to the operation of the shutter — is itself a thermodynamic process which generates entropy. Szilard estimated this entropy at approximately k ln 2 per measurement, where k is the Boltzmann constant; subsequent refinements by Brillouin (1951), Landauer (1961), and Bennett (1982) established that the irreversible erasure of the agent's memory (which must occur if the agent is not to grow without bound) is itself a process of entropy production at a rate not less than k ln 2 per erasure. The aggregate entropy production by measurement and erasure is precisely equal to, or exceeds, the entropy decrease produced by the selective shutter operation, and the Second Law is preserved.

Third, the apparatus is therefore not a violation of the Second Law if all entropy-producing operations are properly accounted; it is rather a mis-stated or incomplete description, the agent's measurement and memory-management costs having been omitted from the energetic accounting of the application. The Bureau notes that the inventor, upon being apprised of these considerations by counsel for the Examiner during the 1925 prosecution, declined to amend the application and instead introduced into the record his nutrient-agar feeding schedule (twice daily) as a candidate energetic input. The Bureau has examined this candidate and finds the total caloric content of the agar to be approximately 3.5 kilocalories per day, this figure being insufficient by approximately fourteen orders of magnitude to support the claimed refrigeration capacity.

Fourth, the apparatus is in any event inoperable for the further reason that an agent of microscopic dimensions, observing the velocity of gas molecules, cannot make such observation without scattering photons or other carriers from the molecule under observation, and the recoil of the molecule under such scattering perturbs its velocity by an amount of order unity, defeating the measurement. The Bureau notes that this difficulty has not been overcome by the inventor's Pseudomonas culture and is unlikely to be overcome by any candidate organism. Citations: Maxwell, J. C., Theory of Heat (1871); Szilard, L., Z. Phys. 53, 840 (1929); Landauer, R., IBM J. Res. Dev. 5, 183 (1961); Bennett, C. H., Int. J. Theor. Phys. 21, 905 (1982).