Noether’s theorems are widely praised as some of the most beautiful and useful results in physics... more Noether’s theorems are widely praised as some of the most beautiful and useful results in physics. However, if one reads the majority of standard texts and literature on the application of Noether’s first theorem to field theory, one immediately finds that the “canonical Noether energy-momentum tensor” derived from the 4-parameter translation of the Poincaré group does not correspond to what’s widely accepted as the “physical” energy-momentum tensor for central theories such as electrodynamics. This gives the impression that Noether’s first theorem is in some sense not working. In recognition of this issue, common practice is to “improve” the canonical Noether energy-momentum tensor by adding suitable ad-hoc “improvement” terms that will convert the canonical expression into the desired result. On the other hand, a less common but distinct method developed by Bessel-Hagen considers gauge symmetries as well as coordinate symmetries when applying Noether’s first theorem; this allows o...
Guth (Phys. Rev. D 23:347–56, 1981) provided a persuasive rationale for inflationary cosmology ba... more Guth (Phys. Rev. D 23:347–56, 1981) provided a persuasive rationale for inflationary cosmology based on its ability to solve fine-tuning problems of big bang cosmology. Yet one of the most important consequences of inflation was only widely recognized a few years later: inflation provides a mechanism for generating small departures from uniformity, needed to seed formation of subsequent structures, by “freezing out” vacuum fluctuations to form classical density perturbations. This paper recounts the historical development of this aspect of inflation and puts it in context of the development of ideas on structure formation in relativistic cosmology, before turning to the comparison between inflation and a competing account of structure formation based on topological defects. One aim is to assess in what sense inflation is empirically tested through its account of the formation of structure, in light of persistent debates among cosmologists regarding whether inflation is “falsifiable.”
Vol. 1. Einstein's Zurich Notebook, Introduction and Source Preface Introduction to Volumes 1... more Vol. 1. Einstein's Zurich Notebook, Introduction and Source Preface Introduction to Volumes 1 and 2 : The Zurich Notebook and the Genesis of General Relativity Michel Janssen, John Norton, Jurgen Renn, Tilman Sauer, and John Stachel Classical Physics in Disarray (Jurgen Renn) The First Two Acts (John Stachel) Pathways out of Classical Physics (Jurgen Renn, Tilman Sauer) Einstein's Zurich Notebook Vol. 2: Einstein's Zurich Notebook, Commentary and Essays Michel Janssen, John Norton, Jurgen Renn, Tilman Sauer, and John Stachel Commentary on the Notes on Gravity in the Zurich Notebook What was Einstein's 'Fateful Prejudice'? (John D..Norton) What Did Einstein Know and When Did He Know It? A Besso Memo Dated August 1913 (Michel Janssen) Untying the Knot: How Einstein Found His Way Back to Field Equations Discarded in the Zurich Notebook (Jurgen Renn and Michel Janssen) Index Vol. 3: Gravitation in the Twilight of Classical Physics, Between Mechanics, Field Theory...
The authors survey some debates about the nature and structure of physical theories and about the... more The authors survey some debates about the nature and structure of physical theories and about the connections between our physical theories and naturalized metaphysics. The discussion is organized around an “ideal view” of physical theories and criticisms that can be raised against it. This view includes controversial commitments regarding the best analysis of physical modalities and intertheory relations. The authors consider the case in favor of taking laws as the primary modal notion, discussing objections related to alleged violations of the laws, the apparent need to appeal to causality, and the status of probability. The “ideal view” includes a commitment that fundamental physical theories are explanatorily sufficient. The authors discuss several challenges to recovering the manifest image from fundamental physics, along with a distinct challenge to reductionism based on acknowledging the contributions of less fundamental theories in physical explanations.
Traditional debates, such as those regarding whether the universe is finite in spatial or tempora... more Traditional debates, such as those regarding whether the universe is finite in spatial or temporal extent, exemplified, according to Kant, the inherent tendency of pure reason to lead us astray. Although various aspects of Kant’s arguments fail to find a footing in modern cosmology, Kant’s objections to the search for a complete objective description of the cosmos are related to three intertwined issues that are still of central importance: the applicability of universal laws, the status of distinctively cosmological laws, and the explanatory sufficiency of laws. We will advocate a broadly Kantian position on these three issues as part of a critical response to a prevalent strain of Leibnizian rationalism in contemporary cosmology.
Inflationary cosmology has been widely accepted due to its successful predictions: for a “generic... more Inflationary cosmology has been widely accepted due to its successful predictions: for a “generic” initial state, inflation produces a homogeneous, flat, bubble with an appropriate spectrum of density perturbations. However, the discovery that inflation is “generically eternal,” leading to a vast multiverse of inflationary bubbles with different low-energy physics, threatens to undermine this account. There is a “predictability crisis” in eternal inflation, because extracting predictions apparently requires a well-defined measure over the multiverse. This has led to discussions of anthropic predictions based on a measure over the multiverse, and an assumption that we are typical observers. I will give a pessimistic assessment of attempts to make predictions in this sense, emphasizing in particular problems that arise even if a unique measure can be found.
This chapter addresses philosophical questions raised in contemporary work on cosmology. It provi... more This chapter addresses philosophical questions raised in contemporary work on cosmology. It provides an overview of the Standard Model for cosmology and argues that its deficiency in addressing theories regarding the very early universe can be resolved by introducing a dynamical phase of evolution that eliminates the need for a special initial state. The chapter also discusses recent hypotheses about dark matter and energy, issues that it relates to philosophical debates about underdetermination.
Draft version, please refer to final version published in Oxford Handbook of Philosophy of Physics (ed. by R. Batterman).
Draft version, please refer to published version in The Blackwell Companion to the Philosophy of ... more Draft version, please refer to published version in The Blackwell Companion to the Philosophy of Time, ed. by A. Bardon and H. Dyke.
Noether’s theorems are widely praised as some of the most beautiful and useful results in physics... more Noether’s theorems are widely praised as some of the most beautiful and useful results in physics. However, if one reads the majority of standard texts and literature on the application of Noether’s first theorem to field theory, one immediately finds that the “canonical Noether energy-momentum tensor” derived from the 4-parameter translation of the Poincaré group does not correspond to what’s widely accepted as the “physical” energy-momentum tensor for central theories such as electrodynamics. This gives the impression that Noether’s first theorem is in some sense not working. In recognition of this issue, common practice is to “improve” the canonical Noether energy-momentum tensor by adding suitable ad-hoc “improvement” terms that will convert the canonical expression into the desired result. On the other hand, a less common but distinct method developed by Bessel-Hagen considers gauge symmetries as well as coordinate symmetries when applying Noether’s first theorem; this allows o...
Guth (Phys. Rev. D 23:347–56, 1981) provided a persuasive rationale for inflationary cosmology ba... more Guth (Phys. Rev. D 23:347–56, 1981) provided a persuasive rationale for inflationary cosmology based on its ability to solve fine-tuning problems of big bang cosmology. Yet one of the most important consequences of inflation was only widely recognized a few years later: inflation provides a mechanism for generating small departures from uniformity, needed to seed formation of subsequent structures, by “freezing out” vacuum fluctuations to form classical density perturbations. This paper recounts the historical development of this aspect of inflation and puts it in context of the development of ideas on structure formation in relativistic cosmology, before turning to the comparison between inflation and a competing account of structure formation based on topological defects. One aim is to assess in what sense inflation is empirically tested through its account of the formation of structure, in light of persistent debates among cosmologists regarding whether inflation is “falsifiable.”
Vol. 1. Einstein's Zurich Notebook, Introduction and Source Preface Introduction to Volumes 1... more Vol. 1. Einstein's Zurich Notebook, Introduction and Source Preface Introduction to Volumes 1 and 2 : The Zurich Notebook and the Genesis of General Relativity Michel Janssen, John Norton, Jurgen Renn, Tilman Sauer, and John Stachel Classical Physics in Disarray (Jurgen Renn) The First Two Acts (John Stachel) Pathways out of Classical Physics (Jurgen Renn, Tilman Sauer) Einstein's Zurich Notebook Vol. 2: Einstein's Zurich Notebook, Commentary and Essays Michel Janssen, John Norton, Jurgen Renn, Tilman Sauer, and John Stachel Commentary on the Notes on Gravity in the Zurich Notebook What was Einstein's 'Fateful Prejudice'? (John D..Norton) What Did Einstein Know and When Did He Know It? A Besso Memo Dated August 1913 (Michel Janssen) Untying the Knot: How Einstein Found His Way Back to Field Equations Discarded in the Zurich Notebook (Jurgen Renn and Michel Janssen) Index Vol. 3: Gravitation in the Twilight of Classical Physics, Between Mechanics, Field Theory...
The authors survey some debates about the nature and structure of physical theories and about the... more The authors survey some debates about the nature and structure of physical theories and about the connections between our physical theories and naturalized metaphysics. The discussion is organized around an “ideal view” of physical theories and criticisms that can be raised against it. This view includes controversial commitments regarding the best analysis of physical modalities and intertheory relations. The authors consider the case in favor of taking laws as the primary modal notion, discussing objections related to alleged violations of the laws, the apparent need to appeal to causality, and the status of probability. The “ideal view” includes a commitment that fundamental physical theories are explanatorily sufficient. The authors discuss several challenges to recovering the manifest image from fundamental physics, along with a distinct challenge to reductionism based on acknowledging the contributions of less fundamental theories in physical explanations.
Traditional debates, such as those regarding whether the universe is finite in spatial or tempora... more Traditional debates, such as those regarding whether the universe is finite in spatial or temporal extent, exemplified, according to Kant, the inherent tendency of pure reason to lead us astray. Although various aspects of Kant’s arguments fail to find a footing in modern cosmology, Kant’s objections to the search for a complete objective description of the cosmos are related to three intertwined issues that are still of central importance: the applicability of universal laws, the status of distinctively cosmological laws, and the explanatory sufficiency of laws. We will advocate a broadly Kantian position on these three issues as part of a critical response to a prevalent strain of Leibnizian rationalism in contemporary cosmology.
Inflationary cosmology has been widely accepted due to its successful predictions: for a “generic... more Inflationary cosmology has been widely accepted due to its successful predictions: for a “generic” initial state, inflation produces a homogeneous, flat, bubble with an appropriate spectrum of density perturbations. However, the discovery that inflation is “generically eternal,” leading to a vast multiverse of inflationary bubbles with different low-energy physics, threatens to undermine this account. There is a “predictability crisis” in eternal inflation, because extracting predictions apparently requires a well-defined measure over the multiverse. This has led to discussions of anthropic predictions based on a measure over the multiverse, and an assumption that we are typical observers. I will give a pessimistic assessment of attempts to make predictions in this sense, emphasizing in particular problems that arise even if a unique measure can be found.
This chapter addresses philosophical questions raised in contemporary work on cosmology. It provi... more This chapter addresses philosophical questions raised in contemporary work on cosmology. It provides an overview of the Standard Model for cosmology and argues that its deficiency in addressing theories regarding the very early universe can be resolved by introducing a dynamical phase of evolution that eliminates the need for a special initial state. The chapter also discusses recent hypotheses about dark matter and energy, issues that it relates to philosophical debates about underdetermination.
Draft version, please refer to final version published in Oxford Handbook of Philosophy of Physics (ed. by R. Batterman).
Draft version, please refer to published version in The Blackwell Companion to the Philosophy of ... more Draft version, please refer to published version in The Blackwell Companion to the Philosophy of Time, ed. by A. Bardon and H. Dyke.
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Papers by Chris Smeenk
Draft version, please refer to final version published in Oxford Handbook of Philosophy of Physics (ed. by R. Batterman).
Draft version, please refer to final version published in Oxford Handbook of Philosophy of Physics (ed. by R. Batterman).