We discuss Boltzmann’s probabilistic explanation of the second law of thermodynamics providing a comprehensive presentation of what is called today the typicality account. Countering its misconception as an alternative explanation, we examine the relation between Boltzmann’s H-theorem and the general typicality argument demonstrating the conceptual continuity between the two. We then discuss the philosophical dimensions of the concept of typicality and its relevance for scientific reasoning in general, in particular for understanding the reduction of macroscopic laws to microscopic laws. Finally, (...) we reply to various common criticisms of the typicality account. (shrink)

There has been growing concern about whether individuals who satisfy neurological criteria for death or who become non-heart-beating organ donors are really dead. This concern has focused on the issue of the potential for recovery that these individuals may still have and whether their conditions are irreversible. In this article I examine the concepts of potentiality and irreversibility that have been invoked in the discussions of the definition of death and non-heart-beating organ donation. I initially focus on the recent (...) challenge by D. Alan Shewmon to accepting any neurological criterion of death. I argue that Shewmon relies on a problematic and unrealistic concept of potentiality, and that a better, more realistic concept of potentiality is consistent with accepting a neurological criterion for death. I then turn to an analysis of how the concept of irreversibility has been used in discussion of non-heart-beating organ donation. Similarly, I argue that some participants in this discussion have invoked a problematic and unrealistic concept of irreversibility. I then propose an alternative, more realistic account of irreversibility that explains how "irreversibility" should be understood in the definition and criteria of death. (shrink)

Uffink and Valente claim that there is no time-asymmetric ingredient that, added to the Hamiltonian equations of motion, allows to obtain the Boltzmann equation within the Lanford’s derivation. This paper is a discussion and a reply to that analysis. More specifically, I focus on two mathematical tools used in this derivation, viz. the Boltzmann–Grad limit and the incoming configurations. Although none of them are time-asymmetric ingredients, by themselves, I claim that the use of incoming configurations, as taken within the B–G (...) limit, is such a time-asymmetric ingredient. Accordingly, this leads to reconsider a kind of Stoßzahlansatz within Lanford’s derivation. (shrink)

I discuss a broad critique of the classical approach to the foundations of statistical mechanics (SM) offered by N. S. Krylov. He claims that the classical approach is in principle incapable of providing the foundations for interpreting the "laws" of statistical physics. Most intriguing are his arguments against adopting a de facto attitude towards the problem of irreversibility. I argue that the best way to understand his critique is as setting the stage for a positive theory which treats SM (...) as a theory in its own right, involving a completely different conception of a system's state. As the orthodox approach treats SM as an extension of the classical or quantum theories (one which deals with large systems), Krylov is advocating a major break with the traditional view of statistical physics. (shrink)

In this paper I examine Albert’s (2000) claim that the low entropy state of the early universe is sufficient to explain irreversible thermodynamic phenomena. In particular, I argue that conditionalising on the initial state of the universe does not have the explanatory power it is presumed to have. I present several arguments to the effect that Albert’s ‘past hypothesis’ alone cannot justify the belief in past non-equilibrium conditions or ground the veracity of records of the past.

The author proposes to show that the actual crisis in microphysics is principally due to the fact that, as quantum mechanics is a theory of stationary states and reversible movements, it fundamentally ignores the notion of a transitory process. The essential characteristic of quantum theories is the result of an evolution of more than two centuries; a period of development essentially devoted to the description of stationary and reversible phenomena. The author's point of view, which reflects that of the school (...) of Louis de Broglie, is that microphysics must now cross a new threshold in giving up the description of stationary states and the calculation of their transition probabilities in favor of attempting to describe the transitions themselves and explain the origin and stability of stationary states. The future seems to him to be one of a microphysics based on irreversibility. (shrink)

Irreversibility, it is claimed, is a much broader concept than is entropy increase, as is shown by the occurrence of certain processes which are irreversible without seeming to involve any intrinsic entropy change. These processes include the spreading outwards into space of particles, or of radiation, and they also include certain biological and mental phenomena. For instance, the irreversible and treelike branching which is characteristic of natural evolution is not entropic when it is considered in itself—i.e. in abstraction from (...) accompanying biochemical and physiological activity. What appears to be the common feature of all forms of irreversibility is the fanning out of trajectories, new entities or new states, in the temporal direction towards the future. (shrink)

It has been a longstanding problem to show how the irreversible behaviour of macroscopic systems can be reconciled with the time-reversal invariance of these same systems when considered from a microscopic point of view. A result by Lanford shows that, under certain conditions, the famous Boltzmann equation, describing the irreversible behaviour of a dilute gas, can be obtained from the time-reversal invariant Hamiltonian equations of motion for the hard spheres model. Here, we examine how and in what sense Lanford’s theorem (...) succeeds in deriving this remarkable result. Many authors have expressed different views on the question which of the ingredients in Lanford’s theorem is responsible for the emergence of irreversibility. We claim that these interpretations miss the target. In fact, we argue that there is no time-asymmetric ingredient at all. (shrink)

It is a remarkable fact that all processes occurring in the observable universe are irre- versible, whereas the equations through which the fundamental laws of physics are formu- lated are invariant under time reversal. The emergence of irreversibility from the funda- mental laws has been a topic of consideration by physicists, astronomers and philosophers since Boltzmann's formulation of his famous \H" theorem. In this paper we shall discuss some aspects of this problem and its connection with the dynamics of (...) space-time, within the framework of modern cosmology. We conclude that the existence of cosmological horizons allows a coupling of the global state of the universe with the local events deter- mined through electromagnetic processes. (shrink)

Two distinct conceptions for the relation between reversible, time-reversal invariant laws of nature and the irreversible behavior of physical systems are outlined. The standard, extrinsic concept of irreversibility is based on the notion of an open system interacting with its environment. An alternative, intrinsic concept of irreversibility does not explicitly refer to any environment at all. Basic aspects of the two concepts are presented and compared with each other. The significance of the terms extrinsic and intrinsic is discussed.

Should the process of ecological restoration be considered a type of moral reparation? Defenders of the restoration process have recently proposed an affirmative answer to this question. The idea itself is not new. Paul Taylor considered the possibility of reparations to the natural world in his seminal work in environmental ethics, Respect for Nature, although Taylor was not directly considering the process of ecological restoration as the means to secure the reparations. In a recent issue of this journal, Ben Almassi (...) has argued that ecological restoration should be understood as a moral repair, i.e., as "a model for rebuilding the moral conditions of relationships". His argument... (shrink)

QED is a fundamental microscopic theory satisfying all the conservation laws and discrete symmetries C, P, T. Yet, dissipative phenomena, organization, and self-organization occur even at this basic microscopic two-body level. How these processes come about and how they are described in QED is discussed. A possible new phase of QED due to self-energy effects leading to self-organization is predicted.

The aim of this paper is to analyze time-asymmetric quantum mechanics with respect of its validity as a non time-reversal invariant, time-asymmetric theory as well as of its ability to determine an arrow of time.

The aim of this paper is to analyze time-asymmetric quantum mechanics with respect to the problems of irreversibility and of time's arrow. We begin with arguing that both problems are conceptually different. Then, we show that, contrary to a common opinion, the theory's ability to describe irreversible quantum processes is not a consequence of the semigroup evolution laws expressing the non-time-reversal invariance of the theory. Finally, we argue that time-asymmetric quantum mechanics, either in Prigogine's version or in Bohm's version, (...) does not solve the problem of the arrow of time because it does not supply a substantial and theoretically founded criterion for distinguishing between the two directions of time. (shrink)

An extension of the hypothetical experiment of Szilard, which involved the action of a one-molecule gas in an isolated isothermal system, is developed to illustrate how irreversibility may arise out of Brownian motion. As this development requires a consideration of nonmolecular components such as wheels and pistons, the thought-experiment is remodeled in molecular terms and appears to function as a perpetuum mobile.

After reviewing recent literature from physics and philosophy, it is concluded that we are still far from having a satisfying explanation of the nature and origins of irreversibility. It is proposed that the most fruitful approach to this problem is to concentrate on conditions needed for a rigorous derivation of the Boltzmann equation.

As soon as 'modernity' was defined as a particular way of con ceiving of time, the questions of tempo rality came to be situated at the heart of the ongoing debate regarding the legitimacy or illegitimacy of the 'modern age'. This has, in turn, readily led to a no less passionate search for the assessment of modernity's foundations which are thought to rest in its typical sense of experiencing temporality. This polemic instance, however, involves polarized perspectives and the consequent risk, (...) always present in dichotomous approaches, of oversimplifying the concepts at stake and smoothing over the intricacies of their history and meaning. Does there really exist something like a ' time of modernity'? This is the central question that the present article examines. 1 Key Words: evolution • modemity • philosophy of history • time irreversibility. (shrink)

This paper studies the influence of agency conflicts on the irreversibility effect. Using a dynamic variant of the static Baron and Myerson :911–930, 1982) adverse selection model, we characterize under which circumstances the irreversibility effect arises in the presence and absence of an agency conflict. In particular, we find that in the presence of an agency conflict the irreversibility effect arises in more circumstances than in the standard first-best analysis that abstracts from agency problems.

There has recently been a good deal of controversy about Landauer's Principle, which is often stated as follows: The erasure of one bit of information in a computational device is necessarily accompanied by a generation of kTln2 heat. This is often generalised to the claim that any logically irreversible operation cannot be implemented in a thermodynamically reversible way. John Norton (2005) and Owen Maroney (2005) both argue that Landauer's Principle has not been shown to hold in general, and Maroney offers (...) a method that he claims instantiates the operation Reset in a thermodynamically reversible way. In this paper we defend the qualitative form of Landauer's Principle, and clarify its quantitative consequences (assuming the second law of thermodynamics). We analyse in detail what it means for a physical system to implement a logical transformation L, and we make this precise by defining the notion of an L-machine. Then we show that logical irreversibility of L implies thermodynamic irreversibility of every corresponding L-machine. We do this in two ways. First, by assuming the phenomenological validity of the Kelvin statement of the second law, and second, by using information-theoretic reasoning. We illustrate our results with the example of the logical transformation 'Reset', and thereby recover the quantitative form of Landauer's Principle. (shrink)

The reversibility problem (better known as the reversibility objection) is usually taken to be an internal problem in the kinetic theory of gases, namely the problem of how to account for the second law of thermodynamics within this theory. Historically, it is seen as an objection that was raised against Boltzmann's kinetic theory of gases, which led Boltzmann to a statistical approach to the kinetic theory, culminating in the development of statistical mechanics. In this paper, I show that in the (...) late nineteenth century, the reversibility problem had a much broader significance - it was widely discussed and certainly not only as an objection to Boltzmann's kinetic theory of gases. In this period, there was a conflict between mechanism and irreversibility in physics which was tied up with central issues in philosophy of science such as materialism, empiricism and the need for mechanistic foundations of physical theories, as well as with concerns about the heat death of the universe. I discuss how this conflict was handled by the major physicists of the period, such as Maxwell, Kelvin, Duhem, Poincaré, Mach and Planck, as well as by a number of lesser-known authors. (shrink)

This paper considers the issue of cryopreservation and the definition of death from an Aristotelian-Thomistic perspective. A central conceptual focus throughout this discussion is the purportedly irreversible nature of death and the criteria by which a human body is considered to be informed by a rational soul. It concludes that a cryopreserved corpse fails to have “life potentially in it” sufficient to satisfy Aristotle’s definition of ensoulment. Therefore, if the possibility that such a corpse may be successfully preserved and resuscitated (...) comes to fruition, one would have to conclude that the person’s rational soul, which had separated from its body at death, has literally reanimated its resuscitated body. Obviously, this conclusion has theological implications that go beyond the scope of this discussion if we regard bodily resuscitation in this manner as a form of technologically induced resurrection. Another apparent implication of the paper’s argument is that, in a limited sense, death loses its irreversible nature. (shrink)

The concept underlying Prigogine's ideas is the asymmetric "lifetime" he introduces into thermodynamics in addition to the symmetric time parameter. By identifying processes by means of causal chains of genidentical events, we examine the intrinsic order of lifetime adopting Grunbaum's symmetric time order. Further, we define the physical meaning and the actuality of the processes under consideration. We conclude that Prigogine's microscopic temporal irreversibility is tacitly assumed at macroscopic level. Moreover, his "new" complementarity lacks any scientific foundation. Finally, we (...) put forward the fact-like origin of temporal irreversibility referring to classical thermodynamics. (shrink)

This essay examines the claim “path dependence entails irreversibility” from the point of view of evolutionary biology. I argue that evolutionary irreversibility possesses many faces, sometimes conflicting with path dependence. I propose an account of path dependence that does not rely on irreversibility and explains why it more naturally coexists with the notion of (contingent) irreversibility developed by the Belgian paleontologist Louis Dollo. However, I argue that we should not conceive of this relationship as necessary.

Some of the most imaginative analyses in contemporary science have been fostered by the paradox of irreversibility. Rendered as a question the paradox reads: How can the anisotropic macrophysical behavior of a system of molecules be reconciled with the underlying reversible molecular model? Attempts to resolve and dissolve the paradox have appealed to large numbers of particles, jammed correlations, unseen perturbations, hidden variables or constraints, uncertainty principles, averaging procedures (e.g., coarse graining and time smoothing), stochastic flaws, cosmological origins, etc. (...) While acknowledging these efforts as important articulations of basic ideas of statistical mechanics, we question their relevance to irreversibility as it occurs in nature. It seems to us that once the emergence of the phenomenon of equilibrium is understood in terms of molecular dynamics, the macroscopic appearance of irreversibility can also be understood in terms of the frequency of forced withdrawals from young equilibria. We believe that the paradox of irreversibility can be resolved in a simple, logically clear, and aesthetically pleasing manner. (shrink)

I. Prigogine has proposed, and the writings of N. S. Krylov to some extent suggest, a novel and unorthodox solution to foundational problems in statistical mechanics. In particular, the view claims to offer new insight into two interconnected problems: understanding the role of probability in physics, and that of reconciling the irreversibility of physical processes with the temporal symmetry of dynamical theories. The approach in question advocates a conception of the state of a system which incorporates features of the (...) quantum mechanical state concept in a context, classical statistical mechanics, where quantum considerations are generally considered to be irrelevant. I examine the plausibility of this new approach by offering an analysis of the various notions of state employed in modern physics. ;In the first chapter, I analyze the conceptual connections between dynamical laws and the nature of a system's state. I argue that laws and states are correlative. In constructing dynamical theories one does not start with a fixed or pre-determined state concept. Neither is one given the laws of the theory from which the conception of state is derived. Rather, we get the law/state structure as a "package." In light of this general analysis, I next examine the notion of state employed in the quantum theory. Here I consider a variety of conceptions of quantum states and assess their ability to answer the "paradoxes" of quantum theory. I pay particular attention to the role of probability and related restrictions on the realization of certain states. The new approach to statistical mechanics proposes to exploit similar restrictions on states in order to resolve the irreversibility problem. But is this unorthodox approach viable? In the final four chapters, I offer a detailed critique of this approach, examining the plausibility of the radical reworking of the state concept. I argue that while some important progress can be made, certain old puzzles remain, and new and difficult ones arise--ones which raise serious doubts about the ultimate success of this particular approach. I conclude, however, by arguing that such radical proposals are not unmotivated; and that novel and unorthodox proposals concerning the foundations of statistical mechanics must be taken seriously. (shrink)

A simple classical mechanical system, consisting of an idealised classical gas in a simple container designed with some reflective barriers in place, is analysed, and shown to give rise to a surprising irreversible behaviour. The behaviour may appear strange to our physical intuition to start with; but more, it appears positively paradoxical, because classical mechanics is supposed to be time symmetric or reversible. The time reversal of any possible mechanical process in this system is also a possible mechanical process. And (...) the system may be started in a time symmetric equilibrium. Yet it evolves a time asymmetric process. The time asymmetry cannot be generated by the mechanical laws and initial state alone. Instead it is generated by something else, identified here as a law-like asymmetric principle of causation. This is argued to be intrinsic to all physics, but not recognised in the orthodox analysis of reversibility. Equally striking, the behaviour illustrates a perpetual motion machine of the second kind. The system can be used to draw thermal energy from a fluid in thermodynamic equilibrium. The system can be started in a simple equilibrium, and be driven to a non-equilibrium state, simply by altering the geometric arrangement of barriers in a container, which can be done without any significant work. Thus an irreversible cycle can be produced. This system starkly contradicts popular views of reversibility and time symmetry widely accepted in physics, and assumed to be conclusive in most modern philosophical discussions of physical time. The conclusion here is the opposite: classical mechanics is reversible in parts, but as a whole theory, a theory of physics that applies to the real world, it is irreversible in principle. (shrink)

There has recently been a good deal of controversy about Landauer's Principle, which is often stated as follows: The erasure of one bit of information in a computational device is necessarily accompanied by a generation of kTln2 heat. This is often generalised to the claim that any logically irreversible operation cannot be implemented in a thermodynamically reversible way. John Norton and Owen Maroney both argue that Landauer's Principle has not been shown to hold in general, and Maroney offers a method (...) that he claims instantiates the operation Reset in a thermodynamically reversible way. In this paper we defend the qualitative form of Landauer's Principle, and clarify its quantitative consequences. We analyse in detail what it means for a physical system to implement a logical transformation L, and we make this precise by defining the notion of an L-machine. Then we show that logical irreversibility of L implies thermodynamic irreversibility of every corresponding L-machine. We do this in two ways. First, by assuming the phenomenological validity of the Kelvin statement of the second law, and second, by using information-theoretic reasoning. We illustrate our results with the example of the logical transformation 'Reset', and thereby recover the quantitative form of Landauer's Principle. (shrink)

The philosophy of Maurice Merleau-Ponty serves both as a ground and a site of departure for Levinas’ thinking. This essay takes up their relationship, with particular regard to the question of whether Merleau-Ponty’s later shift from phenomenology to ontology brings him under Levinas’ critique of ontology as a totalizing philosophy of power that ultimately either denies or negates the radical alterity of the other. Both thinkers are engaged in reconceiving the intersubjective relation, and focus much of their analyses on the (...) problem of Ianguage as the means by which this relation is expressed. However, though similar in scope, they arrive at fundamentally different positions regarding the self-other relationship, while jointly affirming the role paradox plays in the constitution of intersubjectivity. This essay considers not only their differences but their confluences in contributing to this existential question.La philosophie de Maurice Merleau-Ponty sert à la fois de fondement et de point de départ pour la pensée de Lévinas. Le présent article aborde la question de leur relation en cherchant à savoir si le tournant de Merleau-Ponty, qui le mène de la phénoménologie à I’ontologie, place ce dernier sous la critique lévinassienne de I’ontologie comme philosophie totalisante du pouvoir qui, ultimement, nie I’alteriteradicale de l’autre. Les deux penseurs sont engagés dans le projet de reconceptualisation de la relation intersubjective et du langage qui exprime cette relation. Bien que similaires dans leur portée, ils aboutissent à des positions fondamentalement différentes relativement à la question du rapport soi-autre, alors qu’ils reconnaissent tous deux le rôle du paradoxe dans la constitution de I’intersubjectivité. Cet article considère non seulement leurs differences, mais leurs convergences dans la contribution de la question existentielle. (shrink)

There has recently been a good deal of controversy about Landauer's Principle, which is often stated as follows: The erasure of one bit of information in a computational device is necessarily accompanied by a generation of kT ln 2 heat. This is often generalised to the claim that any logically irreversible operation cannot be implemented in a thermodynamically reversible way. John Norton (2005) and Owen Maroney (2005) both argue that Landauer's Principle has not been shown to hold in general, and (...) Maroney offers a method that he claims instantiates the operation reset in a thermodynamically reversible way. In this paper we defend the qualitative form of Landauer's Principle, and clarify its quantitative consequences (assuming the second law of thermodynamics). We analyse in detail what it means for a physical system to implement a logical transformation L, and we make this precise by defining the notion of an L-machine. Then we show that logical irreversibility of L implies thermodynamic irreversibility of every corresponding L-machine. We do this in two ways. First, by assuming the phenomenological validity of the Kelvin statement of the second law, and second, by using information-theoretic reasoning. We illustrate our results with the example of the logical transformation 'reset', and thereby recover the quantitative form of Landauer's Principle. (shrink)

in Ian Jarvie, Karl Milford and David Miller (eds.): Karl Popper: A centenary assessment, Aldershot: Ashgate 2006, Chapter 45, pp. 57–70.

This paper examines the justifications for using infinite systems to 'recover' thermodynamic properties, such as phase transitions (PT), critical phenomena (CP), and irreversibility, from the micro-structure of matter in bulk. Section 2 is a summary of such rigorous methods as in taking the thermodynamic limit (TL) to recover PT and in using renormalization (semi-) group approach (RG) to explain the universality of critical exponents. Section 3 examines various possible justifications for taking TL on physically finite systems. Section 4 discusses (...) the legitimacy of applying TL to the problem of irreversibility and assesses the repercussions for its legitimacy on its home turf. (shrink)

The conceptual foundations of the modern thermodynamic theory related to a large category of far-from-equilibrium phenomena are outlined, and the historical continuity with early developments based on the impossibility of perpetual motion is discussed.In this perspective the discovery of thermodynamic stability criteria around steady or periodic processes, together with a general evolution criterion that is valid in the non-linear region (and thus implying creation of order and applicability to living systems), appears as a most remarkable development indeed. The leading role (...) played by the Brussels school and particularly by Ilya Prigogine is emphasized. (shrink)

«The chapter on «Times's Arrows» is a confusing blend of speculation and possibly wrong ideas.»From a review of M Gell‐Mann's «The Quark and the Jaguar» by P W Anderson in Physics World, August 1994.