In this sequence of philosophical essays about natural science, the author argues that fundamental explanatory laws, the deepest and most admired successes of modern physics, do not in fact describe regularities that exist in nature. Cartwright draws from many real-life examples to propound a novel distinction: that theoretical entities, and the complex and localized laws that describe them, can be interpreted realistically, but the simple unifying laws of basic theory cannot.

A sophisticated and original introduction to the philosophy of quantum mechanics from one of the world’s leading philosophers of physics In this book, Tim Maudlin, one of the world’s leading philosophers of physics, offers a sophisticated, original introduction to the philosophy of quantum mechanics. The briefest, clearest, and most refined account of his influential approach to the subject, the book will be invaluable to all students of philosophy and physics. Quantum mechanics holds a unique place in the (...) history of physics. It has produced the most accurate predictions of any scientific theory, but, more astonishing, there has never been any agreement about what the theory implies about physical reality. Maudlin argues that the very term “quantum theory” is a misnomer. A proper physical theory should clearly describe what is there and what it does—yet standard textbooks present quantum mechanics as a predictive recipe in search of a physical theory. In contrast, Maudlin explores three proper theories that recover the quantum predictions: the indeterministic wavefunction collapse theory of Ghirardi, Rimini, and Weber; the deterministic particle theory of deBroglie and Bohm; and the conceptually challenging Many Worlds theory of Everett. Each offers a radically different proposal for the nature of physical reality, but Maudlin shows that none of them are what they are generally taken to be. (shrink)

This paper highlights the significance of sensory studies and psychophysical investigations of the relations between psychic and physical phenomena for our understanding of the development of the physics discipline, by examining aspects of research on sense perception, physiology, esthetics, and psychology in the work of Gustav Theodor Fechner, Hermann von Helmholtz, Wilhelm Wundt, and Ernst Mach between 1860 and 1871. It complements previous approaches oriented around research on vision, Fechner’s psychophysics, or the founding of experimental psychology, by charting Mach’s (...) engagement with psychophysical experiments in particular. Examining Mach’s study of the senses and esthetics, his changing attitudes toward the mechanical worldview and atomism, and his articulation of comparative understandings of sensual, geometrical, and physical spaces helps set Mach’s emerging epistemological views in the context of his teaching and research. Mach complemented an analytic strategy focused on parallel psychic and physical dimensions of sensation, with a synthetic comparative approach – building analogies between the retina, the individual, and social life, and moving between abstract and sensual spaces. An examination of the broadly based critique that Mach articulated in his 1871 lecture on the conservation of work shows how his historical approach helped Mach cast what he now saw as a narrowly limiting emphasis on mechanics as a phase yet to be overcome. (shrink)

Roughly speaking, classical statistical physics is the branch of theoretical physics that aims to account for the thermal behaviour of macroscopic bodies in terms of a classical mechanical model of their microscopic constituents, with the help of probabilistic assumptions. In the last century and a half, a fair number of approaches have been developed to meet this aim. This study of their foundations assesses their coherence and analyzes the motivations for their basic assumptions, and the interpretations of their (...) central concepts. The most outstanding foundational problems are the explanation of time-asymmetry in thermal behaviour, the relative autonomy of thermal phenomena from their microscopic underpinning, and the meaning of probability. A more or less historic survey is given of the work of Maxwell, Boltzmann and Gibbs in statistical physics, and the problems and objections to which their work gave rise. Next, we review some modern approaches to (i) equilibrium statistical mechanics, such as ergodic theory and the theory of the thermodynamic limit; and to (ii) non-equilibrium statistical mechanics as provided by Lanford's work on the Boltzmann equation, the so-called Bogolyubov-Born-Green-Kirkwood-Yvon approach, and stochastic approaches such as `coarse-graining' and the `open systems' approach. In all cases, we focus on the subtle interplay between probabilistic assumptions, dynamical assumptions, initial conditions and other ingredients used in these approaches. (shrink)

This report reviews what quantum physics and information theory have to tell us about the age-old question, How come existence? No escape is evident from four conclusions: (1) The world cannot be a giant machine, ruled by any preestablished continuum physical law. (2) There is no such thing at the microscopic level as space or time or spacetime continuum. (3) The familiar probability function or functional, and wave equation or functional wave equation, of standard quantum theory provide mere continuum (...) idealizations and by reason of this circumstance conceal the information-theoretic source from which they derive. (4) No element in the description of physics shows itself as closer to primordial than the elementary quantum phenomenon, that is, the elementary device-intermediated act of posing a yes-no physical question and eliciting an answer or, in brief, the elementary act of observer-participancy. Otherwise stated, every physical quantity, every it, derives its ultimate significance from bits, binary yes-or-no indications, a conclusion which we epitomize in the phrase, it from bit. (shrink)

The appeal of materialism lies precisely in this, in its claim to be natural metaphysics within the bounds of science. That a doctrine which promises to gratify our ambition (to know the noumenal) and our caution (not to be unscientific) should have great appeal is hardly something to be wondered at. (Putnam (1983), p.210) Materialism says that all facts, in particular all mental facts, obtain in virtue of the spatio- temporal distribution, and properties, of matter. It was, as Putnam says, (...) “metaphysics within the bounds of science”, but only so long as science was thought to say that the world is made out of matter.1 In this century physicists have learned that there is more in the world than matter and, in any case, matter isn’t quite what it seemed to be. For this reason many philosophers who think that metaphysics should be informed by science advocate physicalism in place of materialism. Physicalism claims that all facts obtain in virtue of the distribution of the fundamental entities and properties –whatever they turn out to be- of completed fundamental physics. Later I will discuss a more precise formulation. But not all contemporary philosophers embrace physicalism. Some- and though a minority not a small or un-influential one- think that physicalism is rather the metaphysics for an unjustified scientism; i.e. it is scientistic metaphysics. Those among them that think that physicalism can be clearly formulated think that it characterizes a. (shrink)

Symmetries play a major role in physics, in particular since the work by E. Noether and H. Weyl in the first half of last century. Herein, we briefly review their role by recalling how symmetry changes allow to conceptually move from classical to relativistic and quantum physics. We then introduce our ongoing theoretical analysis in biology and show that symmetries play a radically different role in this discipline, when compared to those in current physics. By this comparison, (...) we stress that symmetries must be understood in relation to conservation and stability properties, as represented in the theories. We posit that the dynamics of biological organisms, in their various levels of organization, are not just processes, but permanent (extended, in our terminology) critical transitions and, thus, symmetry changes. Within the limits of a relative structural stability (or interval of viability), variability is at the core of these transitions. (shrink)

The book is drawn from the Tarner lectures, delivered in Cambridge in 1993. It is concerned with the ultimate nature of reality, and how this is revealed by modern physical theories such as relativity and quantum theory. The objectivity and rationality of science are defended against the views of relativists and social constructionists. It is claimed that modern physics gives us a tentative and fallible, but nevertheless rational, approach to the nature of physical reality. The role of subjectivity in (...) science is examined in the fields of relativity theory, statistical mechanics and quantum theory, and recent claims of an essential role for human consciousness in physics is rejected. Prospects for a 'Theory of Everything' are considered, and the related question of how to assess scientific progress is carefully examined. (shrink)

This book offers fresh perspective on the role of phenomenology in the philosophy of physics which opens new avenues for discussion among physicists, "standard" philosophers of physics and philosophers with phenomenological leanings. Much has been written on the interrelations between philosophy and physics in the late 19th and early 20th century, and on the emergence of philosophy of science as an autonomous philosophical sub-discipline. This book is about the under-explored role of phenomenology in the development and the (...) philosophical interpretation of 20th century physics. Part 1 examines questions about the origins and value of phenomenological approaches to physics. Does the work of classical phenomenologists such as Husserl, Merleau-Ponty or Heidegger contain elements of systematic value to both the practice and our philosophical understanding of physics? How did classical phenomenology influence “standard” philosophy of science in the Anglo-American and other traditions? Part 2 probes questions on the role of phenomenology in the philosophies of physics and science: - Can phenomenology help to solve “Wigner’s puzzle”, the problem of the "unreasonable effectiveness" of mathematics in describing, explaining and predicting empirical phenomena? - Does phenomenology allow better understanding of the principle of gauge invariance at the core of the standard model of contemporary particle physics? - Does the phenomenological notion of “Lifeworld” stand in opposition to the “scientific metaphysics” movement, or is there potential for dialogue? Part 3 examines the measurement problem. Is the solution outlined by Fritz London and Edmond Bauer merely a re-statement of von Neumann’s view, or should it be regarded as a distinctively phenomenological take on the measurement problem? Is phenomenology a serious contender in continuing discussions of foundational questions of quantum mechanics? Can other interpretational frameworks such as quantum Bayesianism benefit from implementing phenomenological notions such as constitution or horizonal intentionality? (shrink)

A common reductionist assumption is that macro-scale behaviors can be described "bottom-up" if only sufficient details about lower-scale processes are available. The view that an "ideal" or "fundamental" physics would be sufficient to explain all macro-scale phenomena has been met with criticism from philosophers of biology. Specifically, scholars have pointed to the impossibility of deducing biological explanations from physical ones, and to the irreducible nature of distinctively biological processes such as gene regulation and evolution. This paper takes a step (...) back in asking whether bottom-up modeling is feasible even when modeling simple physical systems across scales. By comparing examples of multi-scale modeling in physics and biology, we argue that the “tyranny of scales” problem presents a challenge to reductive explanations in both physics and biology. The problem refers to the scale-dependency of physical and biological behaviors that forces researchers to combine different models relying on different scale-specific mathematical strategies and boundary conditions. Analyzing the ways in which different models are combined in multi-scale modeling also has implications for the relation between physics and biology. Contrary to the assumption that physical science approaches provide reductive explanations in biology, we exemplify how inputs from physics often reveal the importance of macro-scale models and explanations. We illustrate this through an examination of the role of biomechanics modeling in developmental biology. In such contexts, the relation between models at different scales and from different disciplines is neither reductive nor completely autonomous, but interdependent. (shrink)

Niels Bohr was a central figure in quantum physics, well known for his work on atomic structure and his contributions to the Copenhagen interpretation of quantum mechanics. In this book, philosopher of science Slobodan Perović explores the way Bohr practiced and understood physics, and analyzes its implications for our understanding of modern science. Perović develops a novel approach to Bohr’s understanding of physics and his method of inquiry, presenting an exploratory symbiosis of historical and philosophical analysis that (...) uncovers the key aspects of Bohr’s philosophical vision of physics within a given historical context. -/- To better understand the methods that produced Bohr’s breakthrough results in quantum phenomena, Perović clarifies the nature of Bohr’s engagement with the experimental side of physics and lays out the basic distinctions and concepts that characterize his approach. Rich and insightful, Perović’s take on the early history of quantum mechanics and its methodological ramifications sheds vital new light on one of the key figures of modern physics. (shrink)

The way in which philosophers have thought about the scientific method and the nature of good scientific reasoning over the last few centuries has been consistently and heavily influenced by the examples set by physics. The astounding achievements of 19th and 20th century physics demonstrated that physicists had successfully identified methodologies and reasoning patterns that were uniquely well suited to discovering fundamental truths about the natural world. Inspired by this success, generations of philosophers set themselves the goal of (...) taxonomising, codifying, formalising and evaluating these reasoning patterns. Many will concede that this has been a tremendously fruitful exercise that has served both to illuminate characteristic methodological and epistemological features of the physical sciences, and to inform the way that philosophers think about the epistemic ideals served by science more generally. However, as has been widely noted, the great challenges confronted by contemporary physics have led to a number of fundamental shifts in the way that physicists formulate, assess and apply their theories of the physical world. The most prominent examples of this trend occur in the realm of theoretical high energy physics, where many of the most influential theories advocated by physicists lie beyond the reach of extant experimental methods, and are therefore extremely difficult to test empirically. The fact that whole communities of physicists have devoted so much time and effort to evaluating theories that are largely disconnected from experiments and empirical testing suggests that existing philosophical accounts of the epistemology of physics, based as they are on a broadly empiricist conception of physics, are no longer completely apt, or are at least somewhat out of date. This in turn suggests that it is time for philosophers to redirect their attention towards the characteristic reasoning strategies at play in contemporary physics. As well as clarifying the epistemic structure of 21st century physics and providing new stimulation for general debates surrounding the epistemology of science, this will also allow more philosophers to confront and engage with the existential methodological debates currently raging within physics. There is currently intense and wide spread disagreement surrounding what kinds of reasoning strategies can legitimately be employed in the assessment of competing physical theories and research programs. This special issue aims to facilitate the further engagement of philosophers in this crucial debate by collecting eight contributions that both highlight the deep philosophical issues at stake in debates surrounding the proper methodology for theory assessment in physics, and present novel philosophical perspectives on specific reasoning strategies in the physical sciences. (shrink)

It is well known that the process of quantization—constructing a quantum theory out of a classical theory—is not in general a uniquely determined procedure. There are many inequivalent methods that lead to different choices for what to use as our quantum theory. In this paper, I show that by requiring a condition of continuity between classical and quantum physics, we constrain and inform the quantum theories that we end up with.

To model a (particular kind of) physical system, the perspective that encompasses preparations, tests and the interplay between them is crucial. In this paper, we employ the conceptual and technical framework presented by Buffernoir (2023) to model physical systems through this pivotal lens, utilizing Chu spaces. With some intuitive and operational axioms we manage to reproduce the following fundamental and abstract results, as well as (part of) the involved reasoning: (1) the states corresponding to a property form a (bi-orthogonally) closed (...) set; (2) the properties form an orthomodular lattice. Adding some idealistic axioms, we can derive: (1) the pure states form a quantum Kripke frame in the sense of Zhong (2017, 2021, 2023); (2) the properties form an irreducible propositional system in the sense of Piron (1976), isomorphic to the lattice of closed sets of pure states. Our axioms are different from those in Buffernoir (2023): on the one hand, they say less about the structure of mixed states; on the other hand, they are arguably more intuitive and operational. The work formalizes some important reasoning about quantum systems, reveals some implicit idealization behind the Hilbert space formalism of quantum theory and hints at other possible formalisms. Finally, it is argued that the framework can be applied to classical physics at an abstract level as well as naturally extended with probabilities. (shrink)

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Highlighting main issues and controversies, this book brings together current philosophical discussions of symmetry in physics to provide an introduction to the subject for physicists and philosophers. The contributors cover all the fundamental symmetries of modern physics, such as CPT and permutation symmetry, as well as discussing symmetry-breaking and general interpretational issues. Classic texts are followed by new review articles and shorter commentaries for each topic. Suitable for courses on the foundations of physics, philosophy of physics (...) and philosophy of science, the volume is a valuable reference for students and researchers. (shrink)

Jill North offers answers to questions at the heart of the project of interpreting physics. How do we figure out the nature of the world from a mathematically formulated theory? What do we infer about the world when a physical theory can be mathematically formulated in different ways? The notion of structure is crucial to North's answers.

From an early age, humans know a surprising amount about basic physical principles, such as gravity, force, mass, and shape. We can see this in the way that young children play, and manipulate objects around them. The same behaviour has long been observed in primates - chimpanzees have been shown to possess a remarkable ability to make and use simple tools. But what does this tell us about their inner mental state - do they therefore share the same understanding to (...) that of a young child? Do they understand the simple, underlying physical principles involved? Though some people would say that they do, this book reports groundbreaking research that questions whether this really is the case. -/- Folk Physics for Apes challenges the assumptions so often made about apes. It offers us a rare glimpse into the workings of another mind, examining how apes perceive and understand the physical world - an understanding that appears to be both similar to, and yet profoundly different from our own. The book will have broad appeal to evolutionary psychologists, developmental psychologists, and those interested in the sub-disciplines of cognitive science (philosophy, anthropology). The book additionally offers for developmental psychologists some valuable new non-verbal techniques for assessing causal understanding in young children. (shrink)

Most physics theories are deterministic, with the notable exception of quantum mechanics which, however, comes plagued by the so-called measurement problem. This state of affairs might well be due to the inability of standard mathematics to “speak” of indeterminism, its inability to present us a worldview in which new information is created as time passes. In such a case, scientific determinism would only be an illusion due to the timeless mathematical language scientists use. To investigate this possibility it is (...) necessary to develop an alternative mathematical language that is both powerful enough to allow scientists to compute predictions and compatible with indeterminism and the passage of time. We suggest that intuitionistic mathematics provides such a language and we illustrate it in simple terms. (shrink)

Aristotle offers several arguments in Physics viii.8 for his thesis that, when something moves back and forth, it does not undergo a single motion. These arguments occur against the background of a sophisticated theory, expounded in Physics v—vi, of the basic structure of motions and of other continuous entities such as times and magnitudes. The arguments in Physics viii.8 stand in a complex relation to that theory. On the one hand, Aristotle evidently relies on the theory in (...) a number of crucial steps. Yet in other steps he seems to contradict or misapply the theory. This situation offers the occasion to examine Aristotle’s views about some fundamentals in the metaphysics of motion, while also raising questions about the unity of the text which has come down to us as the Physics. (shrink)

Niels Bohr, founding father of modern atomic physics and quantum theory, was as original a philosopher as he was a physicist. This study explores several dimensions of Bohr's vision: the formulation of quantum theory and the problems associated with its interpretation, the notions of complementarity and correspondence, the debates with Einstein about objectivity and realism, and his sense of the infinite harmony of nature. Honner focuses on Bohr's epistemological lesson, the conviction that all our description of nature is dependent (...) on the words we use and the ways we can unambiguously use them. (shrink)

The philosophical problem that stems from the successful application of mathematics in the empirical sciences has recently attracted growing interest within philosophers of mathematics and philosophers of science. Nevertheless, little attention has been devoted to the converse applicability issue of how physical considerations find successful application in mathematics. In this article, focusing on some case studies, I address the latter issue and argue that some successful applications of physics to mathematics essentially depend on the use of conservation principles. I (...) conclude with a short discussion of how the successful interplay between conservation principles and mathematics can be accounted for. (shrink)

This book examines a selection of philosophical issues in the context of specific episodes in the development of physical theories. Advances in science are presented against the historical and philosophical backgrounds in which they occurred. A major aim is to impress upon the reader the essential role that philosophical considerations have played in the actual practice of science. The book begins with some necessary introduction to the history of ancient and early modern science, with major emphasis being given to the (...) two great watersheds of twentieth-century physics: relativity and, especially, quantum mechanics. At times the term 'construction' may seem more appropriate than 'discovery' for the way theories have developed and, especially in the later chapters, the question of the influence of historical, philosophical and even social factors on the very form and content of scientific theories is discussed. (shrink)

Department of History and Philosophy of Science. University of Cambridge, Free School Lane, Cambridge CB2 3RH This paper is concerned with the question of whether atomic particles of the same species, i. e. with the same intrinsic state-independent properties of mass, spin, electric charge, etc, violate the Leibnizian Principle of the Identity of Indiscernibles, in the sense that, while there is more than one of them, their state-dependent properties may also all be the same. The answer depends on what exactly (...) the state-dependent properties of atomic particles are taken to be. On the plausible interpretation that these should comprise all monadic and relational properties that can be expressed in terms of physical magnitudes associated with self-adjoint operators that can be defined for the individual particles, then the weakest form of the Principle is shown to be violated for bosons, fermions and higher-order paraparticles, treated in first quantization *Some of the arguments inn this paper appeared in a thesis submited by one of us (S.F.) In partial fulfilment of the requirements for the PhD degree of the University of London, in 1984. entitled 'Identity and ‘Individuality in Classical and Quantum Physics’. (shrink)

Steen Brock paints a cross-disciplinary picture of the philosophical and scientific background for the rise of the quantum theory. He accounts for the unity of Kantian metaphysics of Nature, the Helmholtzian principles, and the Hamiltonian methods of modern pre-quantum physics. Brock shows how Planck's vision of a generalization of classical physics implies that the original quantum mechanics of Heisenberg can be regarded as a successful attempt to maintain this modern unity of physics.However, for Niels Bohr, the unity (...) of science and metaphysics did not end in the world of physics. The development of quantum physics had general implications both for other sciences and for various philosophical issues. Brock discusses these matters with respect to recent topics within the philosophy of science and major interpretations of Bohr's ideas. The author invites the reader to follow a long andwinding route of thought which, in the end, culminates in Bohr's ideas of complementarity, culture and Spirit. (shrink)

Solid state physics, the study of the physical properties of solid matter, was the most populous subfield of Cold War American physics. Despite prolific contributions to consumer and medical technology, such as the transistor and magnetic resonance imaging, it garnered less professional prestige and public attention than nuclear and particle physics. Solid State Insurrection argues that solid state physics was essential to securing the vast social, political, and financial capital Cold War physics enjoyed in the (...) twentieth century. Solid state’s technological bent, and its challenge to the “pure science” ideal many physicists cherished, helped physics as a whole respond more readily to Cold War social, political, and economic pressures. Its research kept physics economically and technologically relevant, sustaining its cultural standing and policy influence long after the sheen of the Manhattan Project had faded. (shrink)

More than a century ago, Russell launched a forceful attack on causation, arguing not only that modern physics has no need for causal notions but also that our belief in causation is a relic of a pre-scientific view of the world. He thereby initiated a debate about the relations between physics and causation that remains very much alive today. While virtually everybody nowadays rejects Russell's causal eliminativism, many philosophers have been convinced by Russell that the fundamental physical structure (...) of our world doesn't contain causal relations. This raises the question of how to reconcile the central role of causal concepts in the special sciences and in common sense with the putative absence of causation in fundamental physics. (shrink)

We are used to talking about the “structure” posited by a given theory of physics, such as the spacetime structure of relativity. What is “structure”? What does the mathematical structure used to formulate a theory tell us about the physical world according to the theory? What if there are different mathematical formulations of a given theory? Do different formulations posit different structures, or are they merely notational variants? I consider the case of Lagrangian and Hamiltonian classical mechanics. I argue (...) that, contrary to standard wisdom, these are not genuinely equivalent theories: they differ in statespace structure. I suggest that we should be realists about statespace structure. (shrink)

The procedures of validating computer simulations of particle physicsParticle physics events at the LHCLarge Hadron Collider are summarized. Because of the strongly fluctuating particle content of LHC events and detectorDetector interactions, particle-based Monte Carlo methods are an indispensable tool for dataData analysis analysis. Simulation in particle physicsParticle physics is founded on factorizationFactorization and thus its global validation can be realized by validating each individual step in the simulation. This can be accomplished by drawing on results of previousMeasurement measurements, (...) in situ studies, and models. What is particularly important in particle physicsParticle physics is to quantify how well a simulation is validated such that a systematic uncertainty can be assigned to a measurement. The simulation is tested for a wide range of processes and agrees with dataData within the assigned uncertainties. (shrink)

Mark Wilson explores our strategies for understanding the world. We frequently cannot reason about nature in the straightforward manner we anticipate, but must use alternative thought processes that reach useful answers in opaque and roundabout ways; and philosophy must find better descriptive tools to reflect this.

In this paper, I explore Wittgenstein’s philosophical approach to physics, an approach that crystallises in the Tractatus and is then polished—rather than replaced—in his later writings. The question of Wittgenstein’s attitude towards science has been the subject of much scholarly debate. Wittgenstein maintained throughout his life that philosophy, ethics and religion should be kept separate from the natural sciences. In his view, any attempt to apply scientific methodologies to philosophical, ethical and religious discussions is both dangerous and futile. Some (...) interpreters have read this aspect of Wittgenstein’s thinking as expressing a strong hostility to science: Wittgenstein, they suggest, views science in an negative light and, for this reason, wishes to protect other areas from scientific encroachment. Wittgenstein certainly conveys on occasion a deep frustration with what he regards as the increasing dominance of science over other forms of culture. In Culture and Value, we find him writing. (shrink)