Modeling Physical Reality: Satellite Workshop, SOPhiA Conference 2017, September 13

Pictures

werndl
Charlotte Werndl giving her talk on initial conditions dependence and uncertainty in climate science
SOPhiA
After the workshop: Miguel Carretero, unknown participant, Florian Boge, Niels Martens, Nina Retzlaff, Laurenz Hudetz, and Paul Weingartner (left to right)

Description

Physical science aims at a detailed description, explanation, and prediction of natural phenomena. A central tool to this endeavour are scientific models, ranging from strongly abstracting formal constructions used to map physical interactions, such as the standard model of particle physics, simplifying physically implemented dynamical processes, such as computer simulations, or coarse graining and lumping models as used in atmospheric physics, to merely rescaled depictions of relations at scales impossible to handle in practice, such as mechanical models, say, of the solar system.

This workshop brings together researchers from fields as diverse as the philosophy of climate science, mathematics, high energy physics, gravitation, and causation. It aims to investigate, among other things, the relation between models in mathematics and physics, the prospects of causal models of physical reality, or the epistemological status of simulation models as used in high energy physics or climate research.

The workshop is a collaboration between the Universities of Düsseldorf and Salzburg, and the interdisciplinary DFG research unit The Epistemology of the Large Hadron Collider. Travel and accomodation cost for speakers from the research unit is DFG financed.

Organization: Florian Boge, DFG research unit/Interdisciplinary Centre for Science and Technology Studies (IZWT) at BU Wuppertal. Contact: fboge@uni-wuppertal.de

Download the workshop poster here.


Schedule

09:00 − 09:10 General Introduction
Florian Boge, BU Wuppertal
09:10 − 09:15 short break
09:15 − 09:45 The Neglect of Initial Conditions Dependence and Initial Conditions Uncertainty in Climate Science
Charlotte Werndl, Salzburg University
09:45 − 09:50 short break
09:50 − 10:20 From Models to Reality: A Plea for Caution
Niels Martens, RWTH Aachen
10:20 − 10:25 short break
10:25 − 10:55 A Defense for Pluralism of Causality in Physical Explanations
Paul Weingartner, Salzburg University
10:55 − 11:10 coffee break
11:10 − 11:40 Modelizing long-scale behavior in galactic and extra-galactic systems — The parameters of the ΛCDM model
Miguel Carretero, BU Wuppertal
11:40 − 11:45 short break
11:45 − 12:15 A New Proposal how to Handle Counterexamples  to Markov Causation à la Cartwright, or: Fixing the Chemical Factory
Nina Retzlaff, HHU Düsseldorf
12:15 − 12:20 short break
12:20 − 12:50 What Makes Mathematical Structures Models?
Laurenz Hudetz, Salzburg University
12:50 − 12:55 short break
12:55 − 13:25 Simulation Models and Uncertain Reasoning
Florian Boge, BU Wuppertal

Abstracts & Biographical Information About the Speakers

The Neglect of Initial Conditions Dependence and Initial Conditions Uncertainty in Climate Science
Charlotte Werndl, Salzburg University

The talk examines initial conditions dependence and initial conditions uncertainty for climate projections. Climate projections are often described as experiments that do not depend on the initial conditions and that estimate the forced response of the system. Although a prominent claim, it is hardly ever scrutinized, and this talk aims to fill this gap. The conclusion will be that evidence does not support the independence of projections on initial conditions and that thus the forced response of a system is ill-defined. Concerning initial conditions uncertainty, the main contribution will be to identify three kinds of initial conditions uncertainty. The first kind (the one usually discussed) is the uncertainty associated with the spread of the ensemble simulations. The second kind of initial conditions uncertainty arises because the theoretical initial ensemble (relative to which a projection is defined) cannot be used in calculations and has to be approximated by finitely many initial states. The third kind of initial conditions uncertainty arises because of uncertainties in the construction process of the possible initial conditions. To my knowledge, the second and third kinds of uncertainty have hardly been discussed in the philosophy of climate science before.

Charlotte Werndl is Professor of Logic and Philosophy of Science at the Department of Philosophy at the University of Salzburg, Austria, a Visiting Professor at the Centre for Philosophy of Natural and Social Science (CPNSS) and an affiliate of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics,  at the London School of Economics. Previously she was an Associate Professor at the Department of Philosophy, Logic and Scientific Method at the London School of Economics and before that a research fellow at the University of Oxford. She completed a PhD in Philosophy at the University of Cambridge in 2010 and master’s degrees both in mathematics and philosophy at the University of Salzburg in 2006.  She is an editor of the Review of Symbolic Logic and an associate editor of the European Journal for the Philosophy of Science and serves on a number of editorial and advisory boards. She has published papers on climate change, statistical mechanics, mathematical knowledge, chaos theory, predictability, confirmation, evidence, determinism, indeterminism, observational equivalence and underdetermination. Her current work focuses on the philosophy of climate science, evidence and the philosophy of statistics and the foundation of statistical mechanics.

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From Models to Reality: A Plea for Caution
Niels Martens, RWTH Aachen

The philosophy of physics literature is riddled with examples that trivialize reading off the physical content from a set of (symmetry-related) models of a theory. For instance, the claim that, since a velocity boost forms a symmetry mapping between models of Newtonian Gravity, Newton should have immediately renounced belief in absolute velocities, even though a revised theory formulated merely in terms of relative velocities was not available until much later. I disagree.  I will follow a recent trend inspired by Møller-Nielsen in advocating caution when drawing immediate metaphysical conclusions from (symmetries of) models of a theory. I will illustrate several pitfalls using as a case study models of Newtonian Gravity related by (mass) scaling transformations. 

Niels Martens is a postdoctoral researcher in philosophy of physics at the RWTH Aachen, as part of the interdisciplinary research unit “Epistemology of the LHC”. His project concerns issues of explanatory power and underdetermination surrounding the dark matter vs. modified gravity debate. He has recently submitted his DPhil (= PhD) thesis to the University of Oxford, titled “Against Comparativism about Mass in Newtonian Gravity — a Case Study in the Metaphysics of Scale”. He holds an MSt degree in philosophy of physics from the University of Oxford, and a MSc degree in theoretical physics from the University of Groningen. The main question that keeps him up at night is “What is this thing called spacetime?”.

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A Defense for Pluralism of Causality in Physical Explanations
Paul Weingartner, Salzburg University

It will be shown in this talk that a pluralism of causality is needed. Not only, as might be expected, for such different domains as natural sciences and humanities, but even within the domain of physics different causal relations are necessary. This will be illustrated with examples of physical explanations in different domains of physics like Classical Mechanics, Special Relativity, Thermodynamics and Quantum Mechanics. It will be shown that in these different explanations the causal relations have to have different properties.

Paul Weingartner is professor emeritus of philosophy (University Salzburg). 1961 Doctor of philosophy (major: philosophy, minor: physics) at the University of Innsbruck. As research fellow he was studying with Popper, Britzlmayr and Stegmüller. 1965 assistant professor of philosophy (venia legendi), University of Graz. 1966 assistant professor of philosophy (venia legendi), University of Salzburg. 1966 Kardinal Innitzer Price for Philosophy of the year. 1970 Associate Professor of philosophy at the University of Salzburg. 1971 Full Professor of philosophy at the University of Salzburg. 1995 Honorary Doctorate (Dr. h.c.) from Marie Curie Sklodowska University, Lublin (Poland). In 1997 he received a Membership of the New York Academy of Sciences.

His research areas are philosophy of science, logic and philosophy of religion, with a particular focus on laws of nature, causality, truth, necessity and possibility. He published 10 Books, 36 editions and more than 160 articles in renowned journals like the Journal of Symbolic Logic, Journal of Philosophical Logic, Grazer Philosophische Studien, Erkenntnis, and Philosophia Nauralis. In recent times he also published about God, theory of conscience and the natural law in the philosophy of Thomas Aquinas.

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Modelizing long-scale behavior in galactic and extra-galactic systems — The parameters of the ΛCDM model
Miguel Carretero, BU Wuppertal

The so-called Standard Model of Cosmology or ΛCDM has been enjoying great successes during the last decades. Based on the assumption of a cold dark matter particle and the effect of the dark energy, which together conform the 96% of the total energy content of the known universe, the model has been able to reproduce the long-scale behavior in galactic and extra-galactic systems as well as offering a plausible depiction of the universe’s evolution. However, it depends on six free-parameters that are usually regarded by some as a weakness since they have to be chosen carefully. In addition, modelizing different systems involves the necessity of choosing, for instance, different distribution profiles in order to make the model fit with the data. How do we reconcile this freedom with some of the existence claims cosmologists hold, for instance, the existence of dark matter or dark energy?

Miguel-Ángel Carretero-Sahuquillo holds a BSc in Physics and a MSc in Theoretical Physics from the Universitat de València, Spain, with a MSc Thesis on MOND and a relativistic extension. His interests range between cosmology and the current status of theoretical particle physics. Early on, he developed a great interest for philosophy of science which has led him to pursue a PhD in Philosophy. Currently he is part of the “Epistemology of the LHC” project as a member of the subproject “the hierarchy, fine-tuning, and naturalness problem from a philosophical perspective”, hosted by the Bergische Universit¨at Wuppertal and funded by the DFG.

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A New Proposal how to Handle Counterexamples  to Markov Causation à la Cartwright, or: Fixing the Chemical Factory
Nina Retzlaff, HHU Düsseldorf

Cartwright (1999) attacked the causal Markov condition (CMC) by providing a counterexample in which a common cause does not screen off its effects: the chemical factory. We suggest a new  way  to  handle  counterexamples  to  CMC  such  as  Cartwright’s.  We  argue  that  these scenarios  feature  non-causal  dependencies  of  a  certain  kind.  We  then  develop  a representation of this specific kind of non-causal dependence that allows for modeling the problematic  scenarios  in  such  a  way  that  CMC  is  not  violated  anymore  and  compare  our solution to a recent proposal how to handle the problematic scenarios put forward by Schurz (forthcoming).

The talk presents joint work with Alexander Gebharter, postdoc at the DCLPS, University of Düsseldorf. For more information, see www.alexandergebharter.com.

Nina Retzlaff is a research fellow at the Düsseldorf center for Logic and Philosophy of Science (DCLPS) at the Heinrich Heine University  Düsseldorf.  She  studied  mathematics with  a  minor  in  biology  at  the University of Cologne and is interested in quantum mechanics. Her research interests lie in philosophy of science and metaphysics, especially in causality within quantum mechanics. In the context of her PhD thesis, she is investigating causality with regard to quantum mechanics.

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What Makes Mathematical Structures Models?
Laurenz Hudetz, Salzburg University

In order to apply a mathematical model to a real-world system, it has to be endowed with an empirical interpretation; and if a model is furthermore supposed to tell us something about unobservable aspects of the world and its structure, it has to be endowed with an ontological interpretation that goes beyond the empirical. In this talk, I give a rigorous account of what it is to endow mathematical structures with an empirical and ontological interpretation, i.e. what it is that makes mathematical structures models of a part of the world.

First, I explicate the notion of an uninterpreted formal framework and explain how uninterpreted formal frameworks can be extended to pre-interpreted frameworks. Second, I show how pre-interpreted frameworks can be connected to data. For this purpose, I draw on the theory of relational databases to clarify what data collections and data schemas are. This leads to an explication of the notion of empirically interpreted frameworks. Third, I introduce the notion of an ontological conceptual schema in order to explain how empirically interpreted frameworks can be extended to ontologically interpreted frameworks.

I also discuss how my proposal is related to logical empiricist as well as structuralist accounts of interpretation. I argue that my proposal preserves insights from both traditions while improving on each of these accounts in important aspects.

Laurenz Hudetz is a PhD student and research assistant at the Department of Philosophy of the University of Salzburg. He will take up an assistant professorship at the Department of Philosophy, Logic and Scientific Method at the London School of Economics in Fall 2018. His area of specialisation lies in the intersection of philosophy of science and mathematical logic, with a focus on reduction, equivalence and interpretation of scientific theories.

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Simulation Models and Uncertain Reasoning
Florian Boge, BU Wuppertal

Computer simulations (CS) play an integral role in modern science. They are used, e.g., to model and investigate properties of the atmosphere in climate science, investigate the properties of cars, buildings, and other pieces of engineering during the construction phase, and they are involved in the design, execution, and evaluation of highly complex experiments in high energy physics. While it has sometimes been disputed that philosophizing about them can bring about any significant new insights – which may be correct to the extent that the epistemological issues arising in the context of CS are strongly connected to epistemological issues known from other contexts – there still remain some specific issues concerning the role and status of CS in actual research. Most importantly, views about what precisely CS are, epistemologically speaking, strongly contrast or even apparently contradict each other.

In my talk, I will pursue two central aims: I will (i) consider two strongly contrasting views of simulations and demonstrate that these are ultimately complementary, not mutually exclusive, and both have their righteous place in actual scientific practice. The two contrasting views concern, in particular, the view of CS as arguments, developed in papers by Beisbart and Beisbart and Norton, and the view of CS as comparable to or epistemically on par with experiments, as defended notably by M. Morrison. I will then (ii) argue that the main ‘epistemic thrust’ of CS stems from the inferences they promote, not from the inferences that they (arguably) ‘are’. These former inferences, as I will argue, constitute an instance of abductive rather than deductive reasoning, and the specific kind of adbuction invloved makes it understandable how CS can be both, a ‘kind of experiment’ and a ‘kind of argument’.

Florian Boge is a postdoctoral researcher in the DFG funded interdisciplinary project The Epistemology of the Large Hadron Collider and currently stationed at BU Wuppertal. He finished his Dr. Phil. studies at the University of Cologne in January 2017, with a thesis on epistemic and ontologcial interpretations of quantum theory, and with a short stay in Oxford as a recognised student and academic visitor (trinity 2016). He also finished a degree in physics (BSc) at University of Cologne in 2016, with a thesis on probabilities in the many worlds interpretation of quantum theory. His BA/MA research was conducted at HHU Düsseldorf/the Düsseldorf center for Logic and Philosophy of Science (DCLPS), where he also occupied several positions ranging from student assistant to research staff member. The philosophical theses concluding these studies were concerned with skepticism (BA) and trope theory (MA) respectively.

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