In 1885, during initial discussions of J. C. Maxwell's celebrated thermodynamic demon, Whiting(1) observed that the demon-like velocity selection of molecules can occur in a gravitationally bound gas. Recently, a gravitational Maxwell demon has been proposed which makes use of this observation [D. P. Sheehan, J. Glick, and J. D. Means, Found. Phys. 30, 1227 (2000)]. Here we report on numerical simulations that detail its microscopic phase space structure. Results verify the previously hypothesized mechanism of its paradoxical (...) behavior. This system appears to be the only example of a fully classical mechanical Maxwell demon that has not been resolved in favor of the second law of thermodynamics. (shrink)

In this paper, we pursue three general aims: (I) We will define a notion of fundamental opacity and ask whether it can be found in High Energy Physics (HEP), given the involvement of machine learning (ML) and computer simulations (CS) therein. (II) We identify two kinds of non-fundamental, contingent opacity associated with CS and ML in HEP respectively, and ask whether, and if so how, they may be overcome. (III) We address the question of whether any kind of opacity, contingent (...) or fundamental, is unique to ML or CS, or whether they stand in continuity to kinds of opacity associated with other scientific research. (shrink)

In their book The Road to Maxwell's Demon Hemmo & Shenker re-describe the foundations of statistical mechanics from a purely empiricist perspective. The result is refreshing, as well as intriguing, and it goes against much of the literature on the demon. Their conclusion, however, that Maxwell's demon is consistent with statistical mechanics, still leaves open the question of why such a demon hasn't yet been observed on a macroscopic scale. This essay offers a sketch of what (...) a possible answer could look like. (shrink)

Two decades ago, Rolf Landauer (1991) argued that “information is physical” and ought to have a role in the scientific analysis of reality comparable to that of matter, energy, space and time. This would also help to bridge the gap between biology and mathematics and physics. Although it can be argued that we are living in the ‘golden age’ of biology, both because of the great challenges posed by medicine and the environment and the significant advances that have been (...) made—especially in genetics and molecular and cell biology—we feel that information as an essential aspect of life has been neglected, or at least misunderstood. We therefore summon Maxwell’s Demon and its distant relative the ratchet, and apply these to biology. (shrink)

In 1956, the Swedish Parliament decided to invest in a national nuclear energy program. The decision rested on the conviction that it would be in the interest of the nation to use the assets of natural uranium, the advanced reactor technology, and the expertise on nuclear physics that the country had at its disposal. Since the decision concerned the largest investment ever in Swedish industrial politics, the scientists and engineers had to promise that it would lead to a prosperous future. (...) In this article, the utopian discourse and the rhetoric that were developed to support the Swedish nuclear energy program are analyzed. An important conclusion is that the scientific, technological, political, economic, and moral discourse was not sufficient to create political and civil support. Instead, the scientists and engineers had to turn to the world of myths. Thereby, the conflicts between nuclear physics and magic, scientific objectivity and demons, and rationalistic belief in progress and irrational ideas of faith were dissolved. In Sweden, as in many other Western countries during the 1950s, the world was not disenchanted, but re-enchanted. (shrink)

_Demons in the Consulting Room: Echoes of Genocide, Slavery and Extreme Trauma in Psychoanalytic Practice_ isthe second of two volumes addressing the overwhelming, often unmetabolizable feelings related to mourning, both on an individual and mass scale. Authors in this volume explore the potency of ghosts, ghostliness and the darker, often grotesque aspects of these phenomena. While ghosts can be spectral presences that we feel protective of, demons haunt in a particularly virulent way, distorting experience, our sense of reality and our (...) character. Bringing together a collection of clinical and theoretical papers, _emons in the Consulting Room_, reveals how the most extreme types of trauma can continue to have effects across generations, and how these effects manifest in the consulting room. Essays in this volume consider traumas that have affected multiple generations of people, such as the Holocaust, experiences in the gulags, and the experience of slavery. Authors here consider the clinical challenges of working with the demonic force in severe childhood abuse and the effects of serious and prolonged physical injury and illness. Inevitably, there is in such difficult clinical work, the combined effects of hauntings in the analysts and in patients and often in the surrounding culture. In this book, distinguished psychoanalysts explore the myriad forms of ghosts and the demonic, which interfere and disrupt the endlessly difficult psychic work of mourning. It will be of interest to psychotherapists and psychoanalysts, as well as social workers, family therapists, psychologists, and psychiatrists. _emons in the Consulting Room _ill appeal to those specializing in bereavement and trauma and, on a broader level, to sociologists and historians interested in understanding means of coping with loss and grief on both an individual and larger scale basis. (shrink)

This book is the first all-encompassing exploration of the role of demons in philosophical and scientific thought experiments. In Part I, the author explains the importance of thought experiments in science and philosophy. Part II considers Laplace's Demon, whose claim is that the world is completely deterministic. Part III introduces Maxwell's Demon, who - by contrast - experiences a world that is probabilistic and indeterministic. Part IV explores Nietzsche's thesis of the cyclic and eternal recurrence of events. In (...) each case a number of philosophical consequences regarding determinism and indeterminism, the arrows of time, the nature of the mind and free will are said to follow from the Demons's worldviews. The book investigates what these Demons - and others - can and cannot tell us about our world. (shrink)

Peter Lombard lamented the abandonment of Augustine’s position affirming the materiality of demons and the demonic body, since by his time (some 700 years after Augustine), under the influence of the Pseudo-Dionysius, it was generally agreed within the Christian tradition that demons (and angels) are intelligible, disembodied substances. The principles that the cosmos is spatially and materially divided and stratified and that demons share ontologically in the nature of the part that they inhabit allowed figures such as Apuleius, Porphyry, and (...) Augustine to account for various aspects of demonic nature and activity that seemed to follow from reason, revelation, and practical experience. The material body of the demon and its relation to the pneuma, or vehicle of the soul, is often invoked to explain demonic agency and the extent of demonic knowledge and to distinguish between evil and good demons (or angels). The following paper weighs in on and clarifies Augustine’s demonic ontology. Although scholars generally recognise Augustine’s position maintaining that demons possess aerial bodies, nevertheless, the ambiguity surrounding Augustine’s opinion, attested to even by Peter Lombard, is overlooked, and Augustine’s conviction is often taken for granted and supported by citing the prominent City of God, the very work in which Augustine’s own views are suspect. This paper provides support to the assessment of Augustine’s doctrine of the demonic body by examining his cosmology, particularly his spatial and elemental division of the cosmos, and exhibits his adherence to the spatio-material principle according to which a creature’s bodily constitution is cognate with the elemental composition of the physical stratum of the cosmos in which they dwell. The paper concludes by indicating how Augustine’s explanations of demonic agency, far from being ambiguous on the nature of the demonic body, are in fact premised on their aerial corporeality, thereby demonstrating more definitively his conviction that demons possess material bodies. (shrink)

This article treats the verbal and physical altercation between the disguised Odysseus and the local beggar Iros at the start of Odyssey 18 and explores the overlapping ritual and generic aspects of the encounter so as to account for many of its otherwise puzzling features. Beginning with the detailed characterization of Iros at the book's start, I demonstrate how the poet assigns to the parasite properties and modes of behavior that have close analogues in later descriptions of pharmakoi and (...) of famine demons expelled from communities in rites that are documented from different parts of the Greek world from the archaic period on; so too the account of Iros' ejection from the house and of his subsequent fate conforms to the patterns observable in these rituals. The second part of the discussion examines the ways in which the beggars' quarrel anticipates the enmities that the Ionian iambographers would construct with those whom they cast as their echthroi and rivals, and suggests that we see in the Homeric scene an early instance of an iambic-style confrontation presented in poetic form for performance at the symposium. The iambographers' own deployment of the scapegoat and famine demon paradigms for the vilification of their targets promotes the overlap between the epic and iambic material. In both portions of the argument, the discussion observes how the several frames informing the episode in Book 18 coincide with and promote the Odyssey's larger themes. (shrink)

From the physical, mathematical, and conceptual points of view, Roger Joseph Boscovich’s original 1758 formulation of the principle of physical determinism and Pierre-Simon Laplace’s later 1814 ren...

It is demonstrated that Maxwell’s demon can be used to allow a machine to extract energy from a heat bath by use of information that is processed by the demon at a remote location. The model proposed here effectively replaces transmission of energy by transmission of information. For that we use a feedback protocol that enables a net gain by stimulating emission in selected fluctuations around thermal equilibrium. We estimate the down conversion rate and the efficiency of energy (...) extraction from the heat bath. (shrink)

Demons have the power to cause temptations in us, and Christian materialism implies the supervenience of temptations on brain states. This in turn implies that demons bring about temptations by causally interfering with our brains. But if they have such an ability to affect the physical world, it is mysterious why they do not wreak more havoc than they do both to our brains and in the world more generally. Substance dualism provides an elegant solution: demonic temptation is not (...) a species of soul-to-brain causation, but soul-to-soul, and we don’t need to suppose demons have the power to directly affect the physical world. Materialist solutions, in contrast, are ad hoc. (shrink)

It is generally accepted, following Landauer and Bennett, that the process of measurement involves no minimum entropy cost, but the erasure of information in resetting the memory register of a computer to zero requires dissipating heat into the environment. This thesis has been challenged recently in a two-part article by Earman and Norton. I review some relevant observations in the thermodynamics of computation and argue that Earman and Norton are mistaken: there is in principle no entropy cost to the acquisition (...) of information, but the destruction of information does involve an irreducible entropy cost. (shrink)

This paper argues that the idea of a Maxwellian Demon presupposes a notion of non-physical free will. The author has changed her mind in this point later on and now thinks that Mawellian Demons are compatible with mechanics; see her paper on this from 2010 and book from 2012.

A laboratory-testable, solid-state Maxwell demon is proposed that utilizes the electric field energy of an open-gap p-n junction. Numerical results from a commercial semiconductor device simulator (Silvaco International–Atlas) verify primary results from a 1-D analytic model. Present day fabrication techniques appear adequate for laboratory tests of principle.

In this paper, I compare Pierre-Simon Laplace's celebrated formulation of the principle of determinism in his 1814 Essai philosophique sur les probabilités with the formulation of the same principle offered by Roger Joseph Boscovich in his Theoria philosophiae naturalis, published 56 years earlier. This comparison discloses a striking general similarity between the two formulations of determinism as well as certain important differences. Regarding their similarities, both Boscovich's and Laplace's conceptions of determinism involve two mutually interdependent components—ontological and epistemic—and they are (...) both intimately linked with the principles of causality and continuity. Regarding their differences, however, Boscovich's formulation of the principle of determinism turns out not only to be temporally prior to Laplace's but also—being founded on fewer metaphysical principles and more rooted in and elaborated by physical assumptions—to be more precise, complete and comprehensive than Laplace's somewhat parenthetical statement of the doctrine. A detailed analysis of these similarities and differences, so far missing in the literature on the history and philosophy of the concept of determinism, is the main goal of the present paper. (shrink)

Must a Maxwell demon must fail to reverse the second law of thermodynamics? Standard attempts to show it must fail make use of notions of information and computation. None of these attempts have succeeded. Worse they have distracted both supporters and opponents of these attempts from a much simpler demonstration of the necessary failure of a Maxwell's demon that employs no notions of information or computation. It requires only Liouville's theorem and its quantum analog.

The author's aim in this biography is to shed light on the contrasts and polarity—yet relationship—between the rational and the irrational in Gödel's work and personality. On the one hand there is the genius logician whose technical work can be said practically to have attained the limits of what rational thought can produce; on the other hand, one is struck, claims the author, by the irrationality in Gödel's personality and psychic structure, such as his belief in the existence of spirits, (...) demons, angels, the devil, and other evil-wishing forces that he thought had haunted and deprived him of a peaceful existence.As is well known from other biographies, Gödel was of a frail physical health and psychic balance, having suffered from his student days on from bouts of depression and ‘nervous’ breakdowns—generally attributed to being overworked—that required at times short hospitalization in a sanatorium and culminating toward the end of his life in a marked deterioration in his mental health that resulted in his starving himself to death out of fear of being poisoned. These events are only mentioned here in passing.The author, who teaches philosophy at the University of Lille, is naturally interested in Gödel's philosophical views as well as in his metaphysical reflections, such as his thoughts about life after death and the survival of an immaterial soul. From the 1940s Gödel kept a philosophical diary that contains 670 handwritten notes, written in the now defunct Gabelsberger shorthand. Having feared controversies whenever his metaphysical/philosophical views went against the spirit of the times, Gödel was never led to a comprehensive publication of these views, preferring to put these notes in the private format of notebooks that are now preserved in his Nachlassat Princeton University. 1 The author had several opportunities to study the two of these notebooks …. (shrink)

The author's aim in this biography is to shed light on the contrasts and polarity—yet relationship—between the rational and the irrational in Gödel's work and personality. On the one hand there is the genius logician whose technical work can be said practically to have attained the limits of what rational thought can produce; on the other hand, one is struck, claims the author, by the irrationality in Gödel's personality and psychic structure, such as his belief in the existence of spirits, (...) demons, angels, the devil, and other evil-wishing forces that he thought had haunted and deprived him of a peaceful existence.As is well known from other biographies, Gödel was of a frail physical health and psychic balance, having suffered from his student days on from bouts of depression and ‘nervous’ breakdowns—generally attributed to being overworked—that required at times short hospitalization in a sanatorium and culminating toward the end of his life in a marked deterioration in his mental health that resulted in his starving himself to death out of fear of being poisoned. These events are only mentioned here in passing.The author, who teaches philosophy at the University of Lille, is naturally interested in Gödel's philosophical views as well as in his metaphysical reflections, such as his thoughts about life after death and the survival of an immaterial soul. From the 1940s Gödel kept a philosophical diary that contains 670 handwritten notes, written in the now defunct Gabelsberger shorthand. Having feared controversies whenever his metaphysical/philosophical views went against the spirit of the times, Gödel was never led to a comprehensive publication of these views, preferring to put these notes in the private format of notebooks that are now preserved in his Nachlassat Princeton University. 1 The author had several opportunities to study the two of these notebooks …. (shrink)

We present an analysis of Szilard's one-molecule Maxwell's demon, including a detailed entropy accounting, that suggests a general theory of the entropy cost of information. It is shown that the entropy of the demon increases during the expansion step, due to the decoupling of the molecule from the measurement information. It is also shown that there is an entropy symmetry between the measurement and erasure steps, whereby the two steps additivelv share a constant entropy change, but the proportion (...) that occurs during each of the two steps is arbitrary. Therefore the measurement step may be accompanied by an entropy increase, a decrease, or no change at all, and likewise for the erasure step. Generalizing beyond the demon, decorrelation between a physical system and information about that system always causes an entropy increase in the joint system comprised of both the original system and the information. Decorrelation causes a net entropy increase in the universe unless, as in the Szilard demon, the information is used to decrease entropy elsewhere before the correlation is lost. Thus, information is thermodynamically costly precisely to the extent that it is not used to obtain work from the measured system. (shrink)

The analysis of physical and biological systems through models and mathematics of chaotic behavior and nonlinear dynamics rose to prominence in the 1980s. Many authors, most notably Ilya Prigogine and Isabelle Stengers, made glancing references to applications of this new paradigm to the social and historical sciences, but little fruit was harvested until this decade. Physiologists studying irregular heart rhythms, psychologists examining brain activity, biologists graphing population trends, economists tracking stock price movements, military strategists assessing the outbreak of wars, (...) and sociologists modeling the rise of cities, found nonlinear dynamics refreshingly stimulating in reevaluating old theories and creating new ones. Modeling the past was an inevitable extension of this trend, and theorizing on the new historiography soon followed, with the terms of the debate outlined from 1990 to 1993 by Alan Beyerchen, Katherine Hayles, Stephen Kellert, Charles Dyke, myself, and, in the pages of History and Theory, by George Reisch and Donald McCloskey. The subject of "the chaos of history" is now enjoying a healthy exchange of ideas from all sides. This essay: reviews the precedence for integrating chaos and history; gives a brief history of this integration including an evaluation of a critique of Reisch and McCloskey by Roth and Ryckman, and presents a metahistory of how chaos theory explains its own development; defends a chaotic model of historical sequences; gives a specific historical example of nonlinear history; explores the latest trends in the field of self-organization, antichaos, simplexity, and feedback mechanisms, providing data to show that modern and historical social movements change in a parallel fashion; and exorcises Laplace's demon by showing it was always a chimera. (shrink)

The analysis of physical and biological systems through models and mathematics of chaotic behavior and nonlinear dynamics rose to prominence in the 1980s. Many authors, most notably Ilya Prigogine and Isabelle Stengers, made glancing references to applications of this new paradigm to the social and historical sciences, but little fruit was harvested until this decade. Physiologists studying irregular heart rhythms, psychologists examining brain activity, biologists graphing population trends, economists tracking stock price movements, military strategists assessing the outbreak of wars, (...) and sociologists modeling the rise of cities, found nonlinear dynamics refreshingly stimulating in reevaluating old theories and creating new ones. Modeling the past was an inevitable extension of this trend, and theorizing on the new historiography soon followed, with the terms of the debate outlined from 1990 to 1993 by Alan Beyerchen, Katherine Hayles, Stephen Kellert, Charles Dyke, myself, and, in the pages of History and Theory, by George Reisch and Donald McCloskey. The subject of "the chaos of history" is now enjoying a healthy exchange of ideas from all sides. This essay: reviews the precedence for integrating chaos and history; gives a brief history of this integration including an evaluation of a critique of Reisch and McCloskey by Roth and Ryckman, and presents a metahistory of how chaos theory explains its own development; defends a chaotic model of historical sequences; gives a specific historical example of nonlinear history; explores the latest trends in the field of self-organization, antichaos, simplexity, and feedback mechanisms, providing data to show that modern and historical social movements change in a parallel fashion; and exorcises Laplace's demon by showing it was always a chimera. (shrink)

Landauer's principle, often regarded as the basic principle of the thermodynamics of information processing, holds that any logically irreversible manipulation of information, such as the erasure of a bit or the merging of two computation paths, must be accompanied by a corresponding entropy increase in non-information-bearing degrees of freedom of the information-processing apparatus or its environment. Conversely, it is generally accepted that any logically reversible transformation of information can in principle be accomplished by an appropriate physical mechanism operating in (...) a thermodynamically reversible fashion. These notions have sometimes been criticized either as being false, or as being trivial and obvious, and therefore unhelpful for purposes such as explaining why Maxwell's Demon cannot violate the second law of thermodynamics. Here I attempt to refute some of the arguments against Landauer's principle, while arguing that although in a sense it is indeed a straightforward consequence or restatement of the Second Law, it still has considerable pedagogic and explanatory power, especially in the context of other influential ideas in nineteenth and twentieth century physics. Similar arguments have been given by Jeffrey Bub. (shrink)

Este artigo destina-se a introduzir a conferência de Heisenberg "A doutrina goethiana e newtoniana das cores à luz da física moderna", proferida em 1941, cuja tradução é aqui publicada. Analisa-se primeiramente o projeto filosófico de uma ordenação da realidade, desenvolvido pelo físico no início da década de 1940, o qual subjaz à discussão sobre as doutrinas das cores em Goethe e Newton. No segundo momento, faz-se uma exposição de algumas das implicações filosóficas da teoria quântica, com ênfase na interpretação da (...) assim denominada escola de Copenhague. Por fim, procura-se mostrar como a querela entre Goethe e Newton é utilizada para defender as abstrações da física teórica dos ataques da assim denominada "física ariana" e, ao mesmo tempo, preservar o valor das considerações intuitivas de Goethe. This paper aims at exposing the Heisenberg's conference "The teachings of Goethe and Newton on colors in the light of modern physics", presented in 1941, whose translation is presented here. In the first place the paper analyzes the philosophical project of an ordination of the reality, developed by the physicist in the early 1940s and which is the basis for the discussion of the "Teachings of Goethe and Newton on colors". Secondly it exposes some philosophical implications of the quantum theory by emphasizing the point of view of the Copenhagen school. Finally, it shows how the dispute between Goethe and Newton is exploited to defend the abstractions of the theoretical physics against the attacks of the so called "German physicists" and, at the same time, to preserve the worth of the Goethe's intuitive analysis. (shrink)

A particle of molecular dimensions which can exist in two states is associated with a membrane pore through which molecules of a gas can pass. The gas molecules from two identical phases on either side of the membrane may pass only when the particle is in one particular state. If certain restrictions are imposed on the system, then the particle appears to act like a Maxwell's Demon(1) which “handles” the gas molecules during their passage through the pore.

This paper makes a novel linkage between the multiple-computations theorem in philosophy of mind and Landauer’s principle in physics. The multiple-computations theorem implies that certain physical systems implement simultaneously more than one computation. Landauer’s principle implies that the physical implementation of “logically irreversible” functions is accompanied by minimal entropy increase. We show that the multiple-computations theorem is incompatible with, or at least challenges, the universal validity of Landauer’s principle. To this end we provide accounts of both ideas in (...) terms of low-level fundamental concepts in statistical mechanics, thus providing a deeper understanding of these ideas than their standard formulations given in the high-level terms of thermodynamics and cognitive science. Since Landauer’s principle is pivotal in the attempts to derive the universal validity of the second law of thermodynamics in statistical mechanics, our result entails that the multiple-computations theorem has crucial implications with respect to the second law. Finally, our analysis contributes to the understanding of notions, such as “logical irreversibility,” “entropy increase,” “implementing a computation,” in terms of fundamental physics, and to resolving open questions in the literature of both fields, such as: what could it possibly mean that a certain physical process implements a certain computation. (shrink)

Since 2002, at least two kinds of laboratory-testable, solid-state Maxwell demons have been proposed that utilize the electric field energy of an open-gap n-p junction and that seem to challenge the validity of the Second Law of Thermodynamics. In the present paper we present some arguments against the alleged functioning of such devices.

We study a model proposed by Liboff (Found. Phys. Lett. 10:89, 1997) to violate the second law of thermodynamics. Discs are moving without friction in three connected channels inclined by π/3 with respect to each other. Based on the geometry considerations, it was argued that eventually all the discs end up in the middle channel regardless of their initial positions. This would mean a decrease of the entropy of the system and violation of the second law. We argue that no (...) such anomalous behavior occurs in the system. (shrink)

In 1866 J.C. Maxwell thought he had discovered a Maxwellian demon—though not under that description, of course [1]. He thought that the temperature of a gas under gravity would vary inversely with the height of the column. From this he saw that it would then be possible to obtain energy for work from a cooling gas, a clear violation of Thompson’s statement of the second law of thermodynamics. This upsetting conclusion made him worry that “there remains as far as (...) I can see a collision between Dynamics and thermodynamics.” Later, he derived the Maxwell-Boltzmann distribution law that made the temperature the same throughout the column. However, he continued to think about the relationship between dynamics and thermodynamics, and in 1867, he sent Tait a note with a puzzle for him to ponder. The puzzle was his famous “neat-fingered being” who could make a hot system hotter and a cold system colder without any work being done. Thompson in 1874 christened this being a “demon”; Maxwell unsuccessfully tried to rename it “valve.” However named, the demon’s point was to “show that the second law of thermodynamics has only a statistical validity.” Since that time a large physics literature has arisen that asks a question similar to that asked in theology, namely, does the devil exist? Beginning with Popper, philosophers examining the literature on Maxwell’s demon are typically surprised—even horrified [2,3,4,5,6,7]. As a philosopher speaking at a physics conference exactly 100 yrs after Popper’s birth, I want to explain why this is so. The organizers of this conference instructed me to offend everyone, believers and non-believers in demons. Thus my talk, apart from an agnostic middle section, contains a section offending those who believe they have exorcized the demon and a section offending those who summon demons. Throughout the central idea will be to clearly distinguish the various second laws and the various demons.. (shrink)

demon thought experiment remains ambiguous even today. One of the most delightful thought It seems that Maxwell originally invoked experiments in the history of physical science is..

This paper examines demonic agency and epistemology in the thought of Augustine. When Augustine claims that demons can “work miracles,” he means this in a specific sense: the actions and intelligence of demons are only miraculous from the standpoint of humans, whose powers of perception and action are limited in relation to those of demons. The character of demons’ bodies and the length of their lives provide abilities beyond what humans possess, but, as natural, created beings, demons adhere to the (...) physical rules of nature. Demons possess neither supernatural powers, nor perfect knowledge. Just as our wonder ceases when we are shown how a magic trick is executed, human astonishment makes way for rational understanding once we comprehend demonic nature. (shrink)

In this first part of a two-part paper, we describe efforts in the early decades of this century to restrict the extent of violations of the Second Law of thermodynamics that were brought to light by the rise of the kinetic theory and the identification of fluctuation phenomena. We show how these efforts mutated into Szilard’s proposal that Maxwell’s Demon is exorcised by proper attention to the entropy costs associated with the Demon’s memory and information acquisition. In the (...) second part we will argue that the information theoretic exorcisms of the Demon provide largely illusory benefits. According to the case, they either return a presupposition that can be had without information theoretic consideration or they postulate a broader connection between information and entropy than can be sustained. (shrink)

In this second part of our two-part paper we review and analyse attempts since 1950 to use information theoretic notions to exorcise Maxwell’s Demon. We argue through a simple dilemma that these attempted exorcisms are ineffective, whether they follow Szilard in seeking a compensating entropy cost in information acquisition or Landauer in seeking that cost in memory erasure. In so far as the Demon is a thermodynamic system already governed by the Second Law, no further supposition about information (...) and entropy is needed to save the Second Law. In so far as the Demon fails to be such a system, no supposition about the entropy cost of information acquisition and processing can save the Second Law from the Demon. (shrink)

In this paper we propose a theoretical model of protein folding and protein evolution in which a polypeptide (sequence/structure) is assumed to behave as a Maxwell Demon or Information Gathering and Using System (IGUS) that performs measurements aiming at the construction of the native structure. Our model proposes that a physical meaning to Shannon information (H) and Chaitin's algorithmic information (K) parameters can be both defined and referred from the IGUS standpoint. Our hypothesis accounts for the interdependence of (...) protein folding and protein evolution through mutual influencing relationships mediated by the IGUS. In brief, IGUS activity in protein folding determines long term tendencies that emerge at the evolutionary time-scale.Thus, protein evolution is a consequence of measurements executed by proteins at the cellular level, where the IGUS imposes a tendency to attain a highly unique stable native form that promotes the updating of the information content. The folding kinetics observed is, thus, the outcome of an evolutionary process where the polypeptide-IGUS drives the evolution of its linear sequence. Finally, we describe protein evolution as an entropic process that tends to increase the content of mutual algorithmic information between the sequence and the structure. This model enables one: 1. To comprehend that full determination of the three-dimensional structure by the linear sequence is a tendency where satisfaction is only possible at thermodynamic equilibrium .2. To account for the observed randomness of the amino acid sequences. 3. To predict an alternation of periods of selection and neutral diffusion during protein evolutionary time. (shrink)

In my master's thesis for physics and philosophy, I take a long and hard look at the debates surrounding Maxwell's Demon and the status of the second law of thermodynamics. I try to clarify the use of Maxwell's thought experiment in understanding the second law; to prove that the second law is contingent, given only classical mechanics and time asymmetry; to argue that the law only holds because of facts about the kinds of particles that exist in our universe; (...) to show that and why the attempts to banish the demon using fluctuations, measurements or information or erasure have been unsuccessful; and I conclude that Maxwell's Demon is alive and kicking. (shrink)

Landauer’s principle is the loosely formulated notion that the erasure of n bits of information must always incur a cost of k ln n in thermodynamic entropy. It can be formulated as a precise result in statistical mechanics, but for a restricted class of erasure processes that use a thermodynamically irreversible phase space expansion, which is the real origin of the law’s entropy cost and whose necessity has not been demonstrated. General arguments that purport to establish the unconditional validity of (...) the law fail. They turn out to depend on the illicit formation of a canonical ensemble from memory devices holding random data. To exorcise Maxwell’s demon one must show that all candidate devices—the ordinary and the extraordinary—must fail to reverse the second law of thermodynamics. The theorizing surrounding Landauer’s principle is too fragile and too tied to a few specific examples to support such general exorcism. Charles Bennett’s recent extension of Landauer’s principle to the merging of computational paths fails for the same reasons as trouble the original principle. (shrink)

Realism about computation is the view that whether or not a particular physical system is performing a particular computation is at least sometimes a mindindependent feature of reality. The caveat ’at least sometimes’ is necessary here because a realist about computation need not believe that all instances of computation should be realistically construed. The computational theory of mind presupposes realism about computation. If whether or not the human nervous system implements particular computations is not a natural fact about the (...) world that is independent of whether we represent it as doing so, then the computational theory of mind fails to naturalise the mind. Realism about computation is also presupposed by attempts to use computational principles such as Landauer’s Principle to dispel Maxwell’s Demon. Realism about computation has been challenged by Hilary Putnam and John Searle among others. Various arguments have been put forward purporting to show that any physical system of sufficient complexity trivially implements all computations. Ladyman et al. offer a precisification and general proof Landauer’s Principle. In order to do this they present an analysis of what it is for a physical process to implement a logical transformation. In this paper, their analysis is explained and its implications for realism about computation and the use of Landauer’s Principle in foundational debates is assessed. (shrink)

In 1885, during initial discussions of J. C. Maxwell's celebrated thermodynamic demon, Whiting (1) observed that the demon-like velocity selection of molecules can occur in a gravitationally bound gas. Recently, a gravitational Maxwell demon has been proposed which makes use of this observation [D. P. Sheehan, J. Glick, and J. D. Means, Found. Phys. 30, 1227 (2000)]. Here we report on numerical simulations that detail its microscopic phase space structure. Results verify the previously hypothesized mechanism of its (...) paradoxical behavior. This system appears to be the only example of a fully classical mechanical Maxwell demon that has not been resolved in favor of the second law of thermodynamics. (shrink)

Poreskoro, with three cat and four dog heads and a snake with a forked tongue as his tail, is responsible for epidemics of contagious diseases in Romany folklore. The Pishachas of Vedic mythology lurk in charnel houses and graveyards, waiting for humans to infect with madness. In Christian demonology, Pythius is known as the ruler of the eighth circle of the Inferno, bestowing heinous and unspeakable tortures on those who have committed fraud. Demons are the stuff of legends, and they (...) are everywhere in mythology and theology. These are just three of the more than thirty I counted that start with the letter P.How lucky we are for the advent of science. A rational tonic, it scatters our demons, demystifying the world for us—or so, at least, we think. As Canales brilliantly shows in this book, our assumption has been far off the mark. In physics, computer science, genetics, neuroscience, and economics, not to mention in the very foundations of rationality itself, an underworld of imaginary creatures has sustained and continues to inhabit modern science. Scientific demons appear in many guises: as atomic and subatomic particle manipulators, as feedback and parallel-processing experts, as messengers who can travel faster than the speed of light, as computer-code spies, gene and bit selectors in evolution and in informatics, as triggers of cascades from the nano level to the level of full-blown ecological and astrophysical theaters. By inventing them, we have learned that causality does not always hold at the level of atoms, that the speed of message transmission is limited, that living systems spend energy, that perpetual-motion machines are impossible, and that there are corners of the universe we have not imagined.We have all heard of Laplace's Demon, and Maxwell's, but who knew that, borrowing from physics, the historian Henry Adams considered the action of demons in geopolitics or that the economist Paul Samuelson analyzed their role in producing more efficient markets? Who knew that the generation that gave us the Internet and artificial intelligence were tasked by their teachers in graduate school to insert as many demons as possible into their programs? Who among us has heard of Darwin's Demon, or Maxwell-Szilárd-Brillouin's, or Monod's, or Loschmidt's? Who is aware of Norbert Weiner's use of demons in conceptualizing cybernetics, or of the great scholar of Kabbalah Gershom Scholem's comparison between Israel's superfast computers and the Golem?As Canales shows convincingly, it has been difficult for both historians and scientists to countenance demons in science, and so they have been written out, in many ways and many instances, of the histories of which they are part and parcel. Thomas Kuhn and even the more radical philosopher Paul Feyerabend both failed to acknowledge in their social critiques of science the extent to which an imaginary underworld of beings has been constitutive of the modern scientific imagination. Ironically, it was the man who provided a hard-and-fast criterion by which to distinguish scientific and nonscientific pursuits, Karl Popper, who ultimately saw the light. Revisiting his classic book The Logic of Scientific Discovery from 1934, he clarified in Postscript to the Logic of Scientific Discovery in 1982 the extent to which every historical era has been characterized by a particular demon. We moderns believe that science is about facts and numbers, but we are mistaken. As Canales beautifully summarizes the stakes of her project, “What first sets science on its path of discovery—then as now—is the continued use of the imagination.”Tracking the fate of demons in modern thought from Descartes to Lord Kelvin to H. G. Wells to David Bohm, and from Conrad Hal Waddington to Henry Compton to Stephen Hawking and Steven Pinker, Bedeviled assumes that the demons of the church or of paganism and the demons of science differ and resemble each other in ways that can be usefully elaborated. What is more crucial, however, is how such demons become real, how they morph from fears to hopes, and from thought experiments into real experiments, and ultimately to things in this world like computer programs, transistors, and nanorobots. From weather systems to messenger RNAs to black holes, demons emerge everywhere. The hard question is: How does the imagination actually drive discovery and understanding? How does it change our world?Perhaps it has been a sidetrack to consider whether we have or have never been modern. Clearly, what reason will not allow, it perennially recruits for a shadowland that helps us to better see our world. Rather than aiming to exorcise science, one day, of all of its methodological and epistemological ghosts, perhaps we might make peace with the notion that every culture struggles with distinguishing truth from falsehood in its own unique way. Such struggles are sensitive to their times and are accomplished through leaps of imagination. But fear not: the debunking of “Western rationality” casts no wet blanket on the project of Enlightenment. If anything, as Canales writes, “an account of science that considers how scientists themselves do science only risks adding new insights into our repertoire of knowledge.” Perhaps, therefore, there is solace to be gained from the dictum, Always choose the Devil you know. Ultimately, there may be no other way forward. (shrink)

There is not just a desire but a profound human need for enhancement - the irrepressible yearning to become better than ourselves. Today, enhancement is often conceived of in terms of biotechnical intervention: genetic modification, prostheses, implants, drug therapy - even mind uploading. The theme of this book is an ancient form of enhancement: a physical upgrade that involves ethical practices of self-realization. It has been called 'angelification' - a transformation by which people become angels. The parallel process is (...) 'daimonification', or becoming daimones. Ranging in time from Hesiod and Empedocles through Plato and Origen to Plotinus and Christian gnostics, this book explores not only how these two forms of posthuman transformation are related, but also how they connect and chasten modern visions of transhumanist enhancement which generally lack a robust account of moral improvement. (shrink)

Norton describes how a Maxwell’s demon can be exorcised merely by considerations of the conservation of phase volume in classical physics. This exorcism is generalized here to quantum physics.

The present contribution offers an overview of the main problems concerning the representation of the planets in the pre-Islamic Iranian world, the origin of their denominations, their astral roles and the reasons behind their demonization in the Zoroastrian and Manichaean frameworks. This is a preliminary attempt to resume the planetary iconography and iconology in western and eastern Iranian sources, involving also external visual data, such as those coming from Dunhuang and the Chinese world. The article offers an intellectual journey into (...) a net of mutual cultural and spiritual relations, focusing on the image of the heaven (and of its celestial beings), thereby proposing a new synthesis and highlighting a number of intercultural contaminations. (shrink)

We propose a new way of looking at the quantum Maxwell’s demon problem in terms of conditional action. A “conditional action” on a system is a unitary time evolution, selected according to the result of a previous measurement, which can reduce the entropy of the system. However, any conditional action can be realized by an unitary time evolution of a larger system and a subsequent Lüders measurement, whereby the entropy of the entire system is either increased or remains constant. (...) We give some examples that illustrate and confirm our proposal, including the erasure of N qubits and the Szilard engine, thus relating the present approach to the Szilard principle and the Landauer principle that have been discussed as possible solutions of the Maxwell’s demon problem. (shrink)

This is an overview article that contains the discussion of the connection between information and physics at the elementary level. We present a derivation of Lindauer’s bound for heat emission during irreversible logical operation. In this computation the Szilard’s version of Maxwell’s demon paradox is used as a model to design thermodynamic implementation of a single bit of computer memory. Lindauer’s principle also motivates the discussion on the practical and emergent nature of the information. Apart from physics, the principle (...) has implications in philosophy. (shrink)