•  512
    The “Structure” of Physics
    Journal of Philosophy 106 (2): 57-88. 2009.
    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 …Read more
  •  220
    Time in Thermodynamics
    In Criag Callender (ed.), The Oxford Handbook of Philosophy of Time, Oxford University Press. pp. 312--350. 2011.
    Or better: time asymmetry in thermodynamics. Better still: time asymmetry in thermodynamic phenomena. “Time in thermodynamics” misleadingly suggests that thermodynamics will tell us about the fundamental nature of time. But we don’t think that thermodynamics is a fundamental theory. It is a theory of macroscopic behavior, often called a “phenomenological science.” And to the extent that physics can tell us about the fundamental features of the world, including such things as the nature of time, …Read more
  •  217
    An empirical approach to symmetry and probability
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 41 (1): 27-40. 2010.
    We often use symmetries to infer outcomes’ probabilities, as when we infer that each side of a fair coin is equally likely to come up on a given toss. Why are these inferences successful? I argue against answering this with an a priori indifference principle. Reasons to reject that principle are familiar, yet instructive. They point to a new, empirical explanation for the success of our probabilistic predictions. This has implications for indifference reasoning in general. I argue that a priori …Read more
  •  176
    Geometric Possibility (review)
    Philosophical Review 122 (3): 522-525. 2013.
  •  166
    The Structure of a Quantum World
    In Alyssa Ney & David Albert (eds.), The Wave Function: Essays on the Metaphysics of Quantum Mechanics, Oxford University Press. pp. 184-202. 2013.
    I argue that the fundamental space of a quantum mechanical world is the wavefunction's space. I argue for this using some very general principles that guide our inferences to the fundamental nature of a world, for any fundamental physical theory. I suggest that ordinary three-dimensional space exists in such a world, but is non-fundamental; it emerges from the fundamental space of the wavefunction.
  •  150
    What is the Problem about the Time‐Asymmetry of Thermodynamics?—A Reply to Price
    British Journal for the Philosophy of Science 53 (1): 121-136. 2002.
    Huw Price argues that there are two conceptions of the puzzle of the time‐asymmetry of thermodynamics. He thinks this puzzle has remained unsolved for so long partly due to a misunderstanding about which of these conceptions is the right one and what form a solution ought to take. I argue that it is Price's understanding of the problem which is mistaken. Further, it is on the basis of this and other misunderstandings that he disparages a type of account which does, in fact, hold promise of a sol…Read more
  •  124
    Two Views on Time Reversal
    Philosophy of Science 75 (2): 201-223. 2008.
    In a recent paper, Malament (2004) employs a time reversal transformation that differs from the standard one, without explicitly arguing for it. This is a new and important understanding of time reversal that deserves arguing for in its own right. I argue that it improves upon the standard one. Recent discussion has focused on whether velocities should undergo a time reversal operation. I address a prior question: What is the proper notion of time reversal? This is important, for it will affect …Read more
  •  102
    Understanding the Time‐Asymmetry of Radiation
    Philosophy of Science 70 (5): 1086-1097. 2003.
    I discuss the nature of the puzzle about the time‐asymmetry of radiation and argue that its most common formulation is flawed. As a result, many proposed solutions fail to solve the real problem. I discuss a recent proposal of Mathias Frisch as an example of the tendency to address the wrong problem. I go on to suggest that the asymmetry of radiation, like the asymmetry of thermodynamics, results from the initial state of the universe.
  •  99
    A new approach to the relational‐substantival debate
    Oxford Studies in Metaphysics 11 3-43. 2018.
    We should see the debate over the existence of spacetime as a debate about the fundamentality of spatiotemporal structure to the physical world. This is a non-traditional conception of the debate, which captures the spirit of the traditional one. At the same time, it clarifies the point of contention between opposing views and offsets worries that the dispute is stagnant or non-substantive. It also unearths a novel argument for substantivalism, given current physics. Even so, that conclusion can…Read more
  •  72
    This book is a stimulating and engaging discussion of philosophical issues in the foundations of classical electromagnetism. In the rst half, Frisch argues against the standard conception of the theory as consistent and local. The second half is devoted to the puzzle of the arrow of radiation: the fact that waves behave asymmetrically in time, though the laws governing their evolution are temporally symmetric. The book is worthwhile for anyone interested in understanding the physical theory of e…Read more
  •  59
    Physics, Structure, and Reality
    Oxford University Press. 2021.
    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.
  •  34
    Max Jammer’s recent book, Concepts of Simultaneity: From Antiquity to Einstein and Beyond, traces the history of our ideas on simultaneity as they evolved alongside sweeping changes in our understanding of physics. One of the interesting lessons of the book is that, even as our physical theories have become increasingly successful, the question of the proper understanding or interpretation of those theories remains extremely puzzling. The central issue is this: Is the simultaneity of events a re…Read more
  •  17
    Comments and replies from the 2021 Eastern APA book symposium on Jill North's Physics, Structure, and Reality.
  •  6