DE / EN
Current & Ongoing
Particle/ astro/ cosmology discussion group
After the online philosophy of dark matter workshop, a group of roughly 20 scholars (incl. physicists, philosophers and historians) has started a regular, global, online discussion group on the history, philosophy and sociology of the intersection between cosmology, astronomy and particle physics, with an initial focus on dark matter. We meet every two weeks on Wednesdays, from 17:00 till 18:00 CEST. Initially we are discussing the dark matter chapters from Peebles’ recent book “Cosmology’s Century”, but eventually we will move on to other/broader topics that are of interest to the group. If you are interested in joining the "Peebles Fan Club", please contact nmartens [at] uni-bonn.de.
History and Philosophy of Physics Research Seminar (Winter 2021-22)
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Tuesdays from 16:15 to 17:45 CE(S)T.
All sessions can be attended via Zoom; the sessions that are indicated as 'hybrid' below may also be attended in person (HS X at Nussallee 9). Zoom-links and weekly reminders are announced via hpp@listen.uni-bonn.de. Subscribing to this list is possible a) here, b) by sending an empty email to hpp-subscribe@listen.uni-bonn.de, or c) by contacting nmartens[at]uni-bonn[dot]de |
Conveners: |
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12 Oct 2021
Online only |
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Klaus Hentschel (University of Stuttgart)
History of the concept and of mental models of photons: concept-formation in slow-motion Abstract
In the talk I will unfold my idea of a layer-wise semantic accretion which took centuries in the case of light. This case is thus like a slow-motion version of the general process of concept formation which often condenses into far shorter time intervals. I will also discuss a few other models of concept-formation. |
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19 Oct 2021
Hybrid |
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Jan Potters (University of Antwerp & University of Bonn)
Hazy spots on a photographic plate: On the Measurement of the Electron's Charge-To-Mass Ratio Abstract
In 1906, Walter Kaufmann published the results of his highly anticipated experiments on the velocity-dependency of the electron's charge-to-mass ratio. The interest mainly stemmed from Kaufmann's promise that these experiments would be so precise as to allow for a decision between two fundamental approaches to physics at the time: the theory of special relativity and the electromagnetic world view. And the results were clear, according to Kaufmann: the relativistic approach had to be considered as a failure. In this talk, I will focus on one particular aspect of these experiments and the attempts to replicate them, namely the use of photographic plates to capture electrons and measure their velocity and charge-to-mass ratio. I will argue, more specifically, that by analyzing how these photographic plates were produced and handled, one can discern different conceptualizations of the relation between objectivity, precision, and error. By means of the work of Kathryn Olesko, Lorraine Daston and Kelley Wilder, I will then argue that these different conceptualizations can be traced back to different local measurement contexts. In the final part of my talk, I will then reflect on what this could mean for how we study approaches such as the electromagnetic world view, following a debate between Suman Seth and Shaul Katzir. I will suggest, more specifically, that they are not to be seen as a set of explicit theoretical commitments, but rather as a way of going about in either theoretical or experimental practice, and that how this way is given content is, in part, influenced by the local context in which a scientist is active. |
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26 Oct 2021
To be announced |
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Master Presentations on Scientific Realism
Presentation 1 (16:15-17:15): Laura Michler Structural Realism as an Alternative to Standard Scientific Realism: Epistemic Structural Realism vs. Ontic Structural Realism Abstract
In this session, I will present parts of my Bachelor’s thesis in which I argued in favor of scientific realism, yet not for the standard version but for an alternative which is called structural realism (SR). I will analyze whether SR is an alternative to the standard version of scientific realism regarding the way SR addresses the scientific realist’s challenges. The main focus of my thesis is to explore the two versions of structural realism, epistemic structural realism (ESR) and ontic structural realism (OSR), in order to investigate whether both, one or none of these forms can successfully address the problems the standard realist faces. Regarding this matter, I will examine what the epistemic and the ontic version of SR consist in, how they operate and how they respond to the challenges of scientific realism such as the Underdetermination of Theory Choice by Evidence (UTE) and the Pessimistic Meta-Induction (PMI). Presentation 2 (17:15-18:15): tba
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2 Nov 2021
Hybrid |
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Debate: The merits of semi-classical gravity
Proponent: Erik Curiel (MCMP, LMU Munich & BHI Harvard) Opponent: Christian Wüthrich (University of Geneva) |
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9 Nov 2021
Online only |
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Domenico Giulini (University of Hannover)
Lie's 'sphere-geometry' as a tool to generate cosmological solutions Abstract
One of the fundamental problems in mathematical cosmology is how to derive the Friedman equations within a scheme of controlled approximations from Einstein’s field equations, e.g., through averaging. In this talk I will present a new idea of how to analytically construct initial data consisting of generalised apollonian-like packings of black holes, that allows to vastly generalise the old lattice-universe models by Lindquist & Wheeler (1957). In this way we can, in principle, analytically construct initial data of lattice-like cosmological models with any degree of homogeneity. Our approach makes essential use of Lie’s 'sphere geometry’, a part of geometry that so far seems to have found (almost) no application in physics. The talk is based on our 2020 paper https://doi.org/10.1088/1361-6382/ab6a20. |
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16 Nov 2021
Online only |
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Abstract
In this talk I will briefly explain the initial value formulation for Einstein’s equations. Using this formulation, I will then discuss the question of the future stability of the standard models of the universe. Finally, I will the discuss the extent to which it is possible to determine the shape (topology) of the universe on the basis of observations. This naturally leads to a discussion of the Copernican and cosmological principles. |
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23 Nov 2021
Online only |
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Master-Presentation
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30 Nov 2021
Hybrid |
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7 Dec 2021
Online only |
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Debate: Should we build a new collider?
Proponent: Peter Mättig (University of Bonn) Opponent: Sabine Hossenfelder (Frankfurt Institute for Advanced Studies) |
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14 Dec 2021
Hybrid |
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Michela Massimi (University of Edinburgh)
Perspectival modelling as modelling possibilities. Nuclear models around 1930s-1950s. |
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21 Dec 2021
Online only |
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Abstract
A brief (and very personal) history of particle theory in the early '70s between 't Hooft's unraveling of spontaneously broken non-Abelian gauge theories and the experimental discovery of the J/Psi. The creation of grand unified theories was both inevitable and revolutionary, ultimately contributing to a dramatic change in our conception of quantum field theory and global symmetries. |
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11 Jan 2022
Online only |
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Michael Gordin (Princeton University)
Relativistic Bohemia: Einstein’s Theory from Prague’s Perspective Abstract
The history of Albert Einstein’s relativity theory is often told through a fixed set of places: the Bern Patent office, the Zurich Notebooks, and the celebrated presentation of the general theory in Berlin in November 1915. Marginal to this progression of intellectual triumphs is Prague, where Einstein worked at the German University as professor of theoretical physics from April 1911 to August 1912. While in Prague, Einstein for the first time devoted significant attention to expanding his earlier ideas about how to generalize special relativity as a theory of gravity. The so-called “static theory,” which he developed in the Bohemian capital, has been widely considered a failure (when it is considered at all), and serious analysis of his intellectual trajectory typically begins with his subsequent collaboration with Marcel Grossmann in Zurich. This presentation places the static theory within the Prague context to show the many ways in which the development and interpretation of relativity was shaped by his comparatively brief residence in the third city of the Habsburg Empire. In addition to gravitation, the presentation will discuss Einstein’s personal and philosophical connections with his Prague predecessor Ernst Mach and Prague successor Philipp Frank, as well as later Czech interpretations of relativity theory in the decades following Einstein’s departure. |
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18 Jan 2022
Hybrid |
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Dialogue: Philosophy of the Historical Sciences
Paleontology, Geology & Archeology Adrian Currie (University of Exeter) Astronomy & Cosmology Juliusz Doboszewski (University of Bonn & BHI Harvard) |
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25 Jan 2022
Hybrid |
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Debate: Relevance of History of Physics for Philosophy of Physics
Proponent: Dennis Lehmkuhl (University of Bonn) Opponent: Stephan Hartmann (MCMP, LMU Munich) |
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1 Feb 2022
Hybrid |
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Marie Gueguen (Institute of Physics of Rennes 1)
A crack in the track of the Hubble constant: a guide for astrophysical measures in context of high uncertainties Abstract
Measuring the value of the Hubble constant, i.e., the rate at which the universe expands at a given time, has always been a topic of controversy. As early as the 1970’s, Sandage et de Vaucouleurs have been arguing about what the adequate methodology should be for such a delicate experimental measure. Should astronomers focus only their best indicators, e.g. the Cepheids, and improve the precision of this measurement based on a unique object to the best possible? Or should they “spread the risks” , i.e., multiply the indicators and methodologies before averaging over their results? Should a robust agreement across several uncertain measures weigh more than a single 1% precision measurement? This disagreement, I argue, stems from a misconception of what managing the uncertainties associated with such experimental measures require. Astrophysical measurements such as the measure of the Hubble constant, indeed, require a methodology that permits both to reduce the known uncertainties and to track the unknown unknowns. In other words, the methods advocated by Sandage and de Vaucouleurs are both needed, but do not serve the same purpose. Based on the lessons drawn from the Hubble crisis, I suggest a methodological guide for identifying, quantifying and reducing uncertainties in astrophysical measurements. |
2020/2021
History and Philosophy of Physics Research Seminar (Summer)
Time and Place: |
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Tuesdays from 16:15 to 17:45 CEST.
Online via Zoom. Zoom-links and weekly reminders are announced via hpp@listen.uni-bonn.de. Subscribing to this list is possible a) here, b) by sending an empty email to hpp-subscribe@listen.uni-bonn.de, or c) by contacting nmartens[at]uni-bonn[dot]de |
Conveners: |
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13 April 2021
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