Ongoing

• Utrecht Philosophy of Astronomy & Cosmology Colloquium

Upcoming

• Philosophical and Technological Reflections on Contemporary Cosmology, "Abandoning the spacetime-matter dichotomy in astronomy and cosmology", UNAM/Online, 28-30 January 2026
• Modeling the Cosmos: Frontiers in Philosophy of Astrophysics and Cosmology, Milan, 3-4 March 2026

2025

• CNRS-SPS25 winter school Expesciences, "Astronomy & Experiment", Venice, 17-21 Nov 2025
• Ill Jornadas de Epistemologia e Historia de la Astronomia, "What does it mean to believe in the darkness?", Cordoba/online, 3 Nov 2025
• Black Holes, Johan de Wittschool (2nd grade), Utrecht, 17 Oct 2025
• Rethinking planetary and sustainability governance through cosmological imaginaries, “Imaginaries in modern cosmology”, Utrecht, 16-17 Oct 2025
• Spacetime Matters conference, “Let's move beyond the spacetime-matter dichotomy!”, Utrecht, 1-2 Sept 2025
• EPSA2025, "Cosmological Spacetime-Matter Distinction" symposium, Groningen, with Antonio Ferreiro & Sanne Vergouwen, Groningen, 27-30 Aug 2025
• Lichtenberg Work-in-Progress Meeting, "Black Holes as Massive Spacetimes", with Sanne Vergouwen, Bonn, 16 April 2025
• Bonn History and Philosophy of Physics Research Seminar, "Deflating the Spacetime–Matter Dichotomy", with Antonio Ferreiro, Bonn, 15 April 2025
• Nijmegen Science Cafe on Dark Matter, 14 April 2025
• Philosophy of Dark Energy Workshop, “Dark Energy: Spacetime or Matter or a Constant of Nature?”,  13 Jan 2025

2024

• Leiden Theoretical Philosophy Colloquium, "Dark Matter Realism", 8 Nov 2024
• Philosophy of Black Holes Workshop, Utrecht, 12 Nov 2024
• University of Strasbourg Observatory Colloquium, "Philosophy for and with astronomy", Niels Martens, 17 Oct 2024
• 2nd COSMOS History & Philosophy of Cosmology Conference, “Cosmological Spacetime-Matter Distinction Symposium”, with Antonio Ferreiro, Sanne Vergouwen & Alex Fleuren
• ISVW Summer School A theory of everything or nothing, "Nieuw denkkader voor de fysica door het afbreken van het onderscheid tussen ruimtetijd en materie", Leusden, Netherlands, 18 July 2024
• 3rd HPP-NL Workshop, Leiden, 25 June 2024
• New Directions in Foundations of Physics Conference, Logar Valley Slovenia, 31 May - 2 June 2024
• Black Hole Initiative Annual Conference, "10 ways in which the humanities & social sciences can contribute to black hole research",  Harvard, Cambridge, USA, 29-30 May 2024
• 3rd HP&C ngEHT Workshop, panel session, Harvard, Cambridge, USA, 28 May 2024
• Philosophy of Inflation Workshop, Utrecht, 24 May 2024
• Utrechtse Nacht van de Filosofie, "Volgt de wereld de wetten van de natuur?", 18 April 2024
• ARCO seminar (The Astrophysics Research Center of the Open university), "Social science & humanities contributions to the next generation Event Horizon Telescope collaboration", Niels Martens, Online/ The Open University of Israel, 15 April 2024
• Karlsruhe Institute of Technology, "Interdisciplinary collaboration & big science", 19 Feb 2024
• Bochum HPS Research Colloquium, "Building a telescope collaboration", Bochum, 18 Jan 2024
• 2nd HPP-NL Workshop, Utrecht, 8 April 2024

2023

• HPP-NL Workshop, Utrecht, 1 Dec 2023
• II Jornadas de Epistemología e Historia de la Astronomía, "Building a Telescope Collaboration: the case of the ngEHT", Cordoba Argentina/online, 23-24 Nov 2023
• Descartes Colloquium, "Losing track of the spacetime-matter distinction in astronomy & cosmology", Utrecht, 17 Oct 2023
• Research Visit, Black Hole Initiative, Harvard, 4-26 Sept 2023
• British Society for the Philosophy of Science Conference, "Planet-sized Integrated Philosophy of Science” Symposium, 1) "Introduction", 2) "How to Organise a Telescope Collaboration", Bristol, 5-7 July 2023
• MCMP Colloquium, "Losing track of the spacetime-matter distinction in astronomy & cosmology", Online/Munich, 19 July 2023
• DBHC meeting, "Taking the long view: historical, philosophical & cultural aspects of the ngEHT", 16 June 2023
• XXVII International School of Philosophy and Foundations of Physics: Philosophy of Dark Matter, Various Lectures on the Philosophy of Dark Matter & Modified Gravity, Urbino, 5-9 June 2023
  • Lecture 1: Introduction to the philosophy of dark matter & modified gravity
  • Lecture 2: Distinguishing (dark) matter & modified gravity/spacetime
  • Lecture 3: Dark matter realism & explanation
• New Directions in the Foundations of Physics, Viterbo Italy, 26-28 May 2023
• BHI conference, Boston, 17-19 May 2023
• NgEHT HPC workshop, Boston, "One Year of the Collaborations Focus Group",  16 May 2023
• Freudenthal Institute Research Seminar, "The Philosophy of the Next Generation Event Horizon Telescope Collaboration", Utrecht, 11 May 2023
• Gravitational Constant Workshop, St. Andrews, 20-21 April 2023
• C19C Lunchtime Seminar, "The Gravitational Constant: a Philosophical Perspective", St. Andrews/Online, 5 April 2023
• Foundations of Observational, Classical and Semi-Classical Gravitational Physics and The Problem of Agency and Laws of Nature, "Taking the long view: historical, philosophical & cultural aspects of the ngEHT", Munich, 28-31 March 2023
• Freudenthal Institute Research Seminar, "The Philosophy of Dark Energy", Utrecht, 23 March 2023
• Utrecht Philosophy & Foundations of Physics Research Seminar, "Doing More with Less - Dark Matter & Modified Gravity", Utrecht, 10 March 2023
• Theoretical Equivalence Workshop, "Constants of Nature & Theoretical Equivalence (video)", Birmingham, 24 Feb 2023
• Dutch Black Hole Consortium Meeting, UTwente, 24 Jan 2023

2022

• Large-Scale Experiments -- Reflecting on Theories and Practices, Karlsruhe, 8-10 Dec 2022
• St. Andrews/Bonn Gravitational Constant Network Meeting, Bonn, 5-7 Dec 2022
• PSA2022, Symposium "Interpreting Theories of Modified Gravity", "The Spacetime-Matter Distinction", Pittsburgh, 10-13 Nov 2022
• Lichtenberg Research Seminar in History and Philosophy of Physics (co-convener, with Juliusz Doboszewski), Bonn (hybrid)
• Dutch Black Hole Consortium Meeting, Utrecht, 30 Sept 2022
• GWP2022 - German Society for Philosophy of Science Conference, "Comparing the explanatory power of ?CDM & modified gravity" (based on joint work with Martin King), Berlin, 15-17 Aug 2022
• Dutch Black Hole Consortium Meeting, Leiden, 7 July 2022
• Persistence in Stability Workshop, "Persistence & Stability: the case of Dark Matter", Bonn, 4-5 July 2022
• History, Philosophy & Sociology of Cosmology & Astroparticle Physics (HPS-CAP) conference, Bonn, 29-30 June 2022
• Next Generation Event Horizon Telescope Meeting, "Scientific collaborations: what makes them work?", Granada, 22-25 June 2022
• New Directions in the Foundations of Physics, Viterbo, Italy, 27-29 May 2022
• Möbius Seminar, "Philosophy of Dark Matter", Paris/online, 19 May 2022
• BHI Foundations Seminar, Black Hole Initiative, "The role of hybrid theories in bridging the divide between dark matter & modified gravity" (video), Harvard/Online, 4 April 2022
• DPG AGPhil conference, Heidelberg/online, 21-25 March 2022
• ELHC Spring School "History, Philosophy & Sociology of Large Physics Experiments", co-organiser of "Material Cultures of Large Physics Experiments" working group, Wuppertal, 13-20 March 2022
• Kick-off Workshop of the History Philosophy Culture working group of the ngEHT collaboration, "Epistemology of the LHC", co-lead of the collaborations section w/ Peter Galison, Boston, 28 Feb-1 March 2022
• Vossius Center for the History of Humanities and Sciences, Junior Visiting Fellow, University of Amsterdam, 31 Jan - 11 March 2022

2021

• Third Weekendseminar in Philosophy of Physics, Working Group "Philosophy of Space(time) & Matter", Cologne (online), 10-12 Dec 2021
• OZSW2021, "Semantic Realism", Tilburg, 3-4 Dec 2021
• Foundations 2020/21, "Comparing the explanatory power of ?CDM & modified gravity" (based on joint work with Martin King), Paris, 28-30 Oct 2021
• European Philosophy of Science Association Biannual Conference 2021, Symposium "Models in Particle Physics: Three Challenges to Realism" with Florian Boge & Martin King, "It's too early for dark matter realism", Turin, 15-18 Sept 2021
• Society for the Metaphysics of Science Annual Conference 2021, "Semantic Realism", online, 1-4 Sept 2021
• British Society for the Philosophy of Science Annual Conference 2021, Symposium "Models in Particle Physics: Three Challenges to Realism" with Florian Boge & Martin King, "It's too early for dark matter realism", online, 5-7 July 2021
• The Dialectic, "Newton would have been justified in believing in unobservable absolute velocities", Niels Martens (Proponent) and Tushar Menon (Opponent), Cambridge University (online), 1 July 2021
• Philosophy of Lambda Workshop (co-organiser, with Juliusz Doboszewski), online, 16 June 2021
• New Directions in Foundations of Physics, online, 4 June 2021
• Philosophy of Dark Matter Workshop (organiser & speaker), "Dark Matter Realism", online, 29-30 March 2021
• Lichtenberg Research Seminar in History and Philosophy of Physics (co-convener, with Dennis Lehmkuhl), Bonn (hybrid), weekly
• Peebles Fan Club: Global, Online Discussion Group on the History, Philosophy & Sociology of the intersection between Cosmology, Astronomy & Particle Physics, fortnightly

2020

• Vossius Seminar, "The divide between dark matter and modified gravity", University of Amsterdam, 5 Oct 2020
• Methodological Issues in the Metaphysics of Science,  "Sensible metaphysics without the final physical theory" with Niels Linnemann, virtual workshop, 28-29 Sept 2020
• 10th European Congress of Analytic Philosophy, "Cartography of the space of theories: an interpretational chart for fields that are both (dark) matter and spacetime", (video only, due to corona), Aug 2020
• British Society for the Philosophy of Science Annual Conference, "Comparing the explanatory power of ?CDM & modified gravity", (padlet only, due to corona), July 2020
• Pacific APA Meeting, "The role of explanatory power in symmetry-to-reality inferences'', San Francisco, 8-11 April 2020 (cancelled due to corona)
• Vossius Center for the History of Humanities and Sciences, Junior Visiting Fellow, University of Amsterdam, 1-28 Feb 2020
• Lichtenberg Research Seminar in History and Philosophy of Physics (co-convener, with Dennis Lehmkuhl), Bonn (hybrid), weekly

2019

• Lugano Quantities Conference, "Absolutism vs. Comparativism about Mass in Newtonian Gravity", 16-17 Nov 2019
• Beyond the Standard Model: historical-critical perspectives, Galileo Galelei Institute for Theoretical Physics, Florence, 14-27 Oct 2019
• The functioning of galaxies: challenges for Newtonian and Milgromian dynamics, Bonn, 23-27 Sept 2019
• First Oxford-Notre Dame-Bonn Workshop on the Foundations of Spacetime Theories, "Dark Matter = Modified Gravity?'', Oxford, 3-4 Sept 2019
• BSPS 2019, Durham, 17-19 July 2019
• 't Hooft 2019 - From Weak Force to Black Hole Thermodynamics and Beyond, Utrecht, 9-11 July 2019
• Simplicities & Complexities Conference (co-organiser), 22-24 May 2019
• Aachen youngDFG pub philosophy, "Scientific Realism vs Anti-realism", 8 May 2019
• The German Society for Philosophy of Science Conference, "Dark Matter = Modified Gravity?'', Cologne, 25-27 Feb 2019
• Dark Matter & Modified Gravity Conference (co-organiser & speaker), "Dark Matter = Modified Gravity?'', RWTH Aachen, 6-8 Feb 2019.

2018

• Research Colloquium, "Dark Matter = Modified Gravity?", University of Cologne, 13 Dec 2018
• DFG Weekend Seminar 'Introduction to Philosophy of Physics', Working Group 'Distinguishing Spacetime and Matter', University of Bonn, 7-9 Dec 2018
• Theory of Science and Technology Colloquium, "Dark Matter = Modified Gravity?'', Aachen, 6 Dec 2018
• Society for the Metaphysics of Science 2018, "Machian Comparativism about Mass" (slides), Milan, 22-24 August 2018, commentator: Zee Perry. I'm also commenting on Dustin Lazarovici's “Super-Humeanism: A Starving Ontology” (handout)
• Particle Physics at the Crossroads, International Summer School on the Philosophy, History and Sociology of Particle Physics, Dark Matter & Modified Gravity Working Group, Wuppertal, 23-30 July 2018
• Foundations2018, "Symmetry-to-reality inferences: The Aharonov-Bohm Effect as a Case Study for Motivational Realism'' (handout), Utrecht, 10-13 July
• British Society for the Philosophy of Science, "Modified Gravity = Dark Matter? Scrutinising the spacetime-matter distinction via the modified gravity/ dark matter lens", Oxford, 4-6 July 2018
• Fifth International Conference on the Nature and Ontology of Spacetime, "Modified Gravity = Dark Matter? Scrutinising the spacetime-matter distinction via the modified gravity/ dark matter lens", Varna, Bulgaria, 14-17 May 2018
• Visit to the Geneva Symmetry Group, 2-9 May 2018, including my "Modified Gravity = Dark Matter?" talk on 3 May (see abstract / video)
• Visits to Oxford University, to collaborate with Dennis Lehmkuhl, 16-23 January & 7-14 March 2018
• Naturalness, Hierarchy, and Fine Tuning, RWTH Aachen, 28 Feb - 2 March 2018

2017

• Visit to Oxford University, to collaborate with James Read and Thomas Møller-Nielsen, 13-15 December 2017
• Spacetime: Fundamental or Emergent?, Bonn, 26-28 Oct 2017
• Visit to Oxford University, to collaborate with Dennis Lehmkuhl and Oliver Pooley, 18-22 Sept 2017
• SOPhiA2017, Modeling Physical Reality Workshop, "From Models to Reality: A Plea for Caution" (handout),  Salzburg, 13-15 Sept 2017
• Cosmology and the Future of Spacetime, Rotman Institute, London, Ontario, 12-14 June 2017
• The Foundation of Reality: Fundamentality, Space and Time, Oxford, 13-15 March 2017

2016

• PSA Biennial Meeting, "Regularity Comparativism about Mass in Newtonian Gravity" (handout), Atlanta, 3-5 Nov 2016
• Oxford Philosophy of Physics Research Seminar, ``Comparativism about Mass in Newtonian Gravity" (abstract / handout), 20 Oct 2016
• "Does a rolling stone gather nomos?": Humeanism (Tushar Menon) vs Anti-Humeanism (Niels Martens) debate (handout), PoP-Grunch, Oxford, 13 Oct 2016
• Society for the Metaphysics of Science Annual Conference, "Regularity Comparativism about Mass in Newtonian Gravity" (handout), Geneva, 15-17 Sept 2016. Commentator: C.D. McCoy
• Dark Matter(s), 4th Fine-Tuning Workshop, Oxford, 8 Sept 2016
• Foundations2016, ``Against Reducing Newtonian Mass to Kinematical Quantities'' (handout), LSE, 16-18 July 2016
• The Hole Shebang, 15 July 2016, LSE
• Structure in Metaphysics, Oxford, 1 June 2016
• Lakatos Workshop: Geometry and Physics, LSE, London, 4 May 2016
• PoP-Grunch, ``The Regularity Approach to Comparativism about Dynamical Quantities'' (handout), Oxford, 11 Feb 2016

2015

• Ockham Society, ``Against Reducing Newtonian Mass to Kinematical Notions'' (handout), Oxford, 25 November 2015
• The Cambridge Masterclass in Philosophy of Physics: Thermal Physics, Cambridge, 14 November 2015
• Centennial workshop on GR, Bristol, 4 Nov 2015
• Visiting Student Research Collaborator at Princeton, 16 Sept - 31 Oct 2015, collaborating with Prof. Shamik Dasgupta
• Society for the Metaphysics of Science, First Annual Conference, Rutgers University - Newark, 17-18 Sept 2015
• 4th Tübingen Summer School in the History and Philosophy of Science: Idealizations in Physics, Lecturer: John Norton, ``The Empirical Adequacy of Comparativism about Mass in Newtonian Gravity'' (handout), 27-31 July 2015
• HarveyBrownFest, Oxford, 13-14 July 2015
• British Society for the Philosophy of Science Annual Conference, Manchester, 2-3 July 2015
• POP-Grunch (Oxford PhilPhys Grad Lunch Seminar), `Comparativism about Mass & the Initial Variable Problem' (handout), 11 June 2015
• Metaphysics of Quantities Conference, `Comparativism about Mass & the Initial Variable Problem' (abstract/ handout), NYU, 1-3 May 2015. Commentator: Eddy Keming Chen
• 1st Munich Graduate Workshop in Mathematical Philosophy: Philosophy of Physics, `Comparativism about Mass & the Initial Variable Problem' (handout), 9-11 April 2015
• Outreach talk on PhilPhys, North London Collegiate's Philosophy Society, 26 March 2015
• DPG 2015 Berlin, `Against Comparativism about Mass in Newtonian Gravity' (handout/ video), 15-20 March 2015
• Quantum Foundations of Statistical Mechanics Workshop (focusing on the recent work of David Wallace), Oxford, 16-17 March 2015
• Ockham Society, `Ozma Games: Talking Physics with Aliens', Oxford, 12 March 2015
• Socrates Society, `Ozma Problems: Talking Physics with Aliens', Oxford, 26 Feb 2015
• Jeremy Butterfield Fest, Cambridge, 6-7 Feb 2015

2014

• Bucharest Graduate Conference in Early Modern Philosophy, `Against Comparativism about Mass in Newtonian Gravity' (handout), 28-29 November 2014
• DPhil Seminar, `Against Comparativism about Mass' (abstract/ handout), University of Oxford, Department of Philosophy, 23 Oct 2014. Commentator: Dennis Lehmkuhl
• Lakatos Award Conference on Philosophy of Physics, London, LSE, 21 Oct 2014
• 2nd International Topoi Conference: The Metaphysics of Quantum Mechanics, Oxford, 2-3 Oct 2014
• Modern Issues in Foundations of Physics: A Workshop in Honour of Chris Isham's 70th birthday, Imperial College London, 26-28 Sept 2014
• Philosophy of Cosmology UK/US Conference, Tenerife, 13-16 Sept 2014
• SOPhiA 2014, `Comparativism about mass' (abstract/ handout), Salzburg, 4-6 Sept 2014. (Chair of one of the PhilSci sessions)
• Summer School: Arches and Scaffoldings: Continuity and Discontinuity in the Genesis of Special Relativity, General Relativity, and Quantum Mechanics, `Comparativism about mass in Newtonian Gravity' (abstract/ handout), Tübingen, 4-8 Aug 2014
• BSPS Conference 2014, Cambridge University, UK, 10-11 July 2014. Followed by the Joint Session of the Aristotelian Society and the Mind Association, 11-13 July 2014.
• Fundamentality and Parsimony Workshop, Nottingham, 4 July 2014
• OZSW Graduate Conference for Theoretical Philosophy 2014, 'The Metaphysics of Emergent Spacetime Theories (abstract/ handout)', Vrije Universiteit Amsterdam, the Netherlands, 26-28 May 2014.
• Establishing the Philosophy of Cosmology, Conference 5: Cosmology and the Constants of Nature, Cambridge University, 17-19 March 2014
• Outreach presentation for Chinese prospective applicants to UK universities, 'Introduction to Philosophy of Physics (slides)', First UK/Oxford Summer Courses, St. Anne's College, Oxford University, 2 Feb 2014

2013

• Establishing the Philosophy of Cosmology, Conference 4: Anthropics, Selection Effects and Fine-Tuning in Cosmology, Oxford University, 2-4 Dec 2013
• Irreversibility in Axiomatic Thermodynamics, Trinity College, Cambridge University, 30 Nov 2013
• Relativity Meets Quantum Theory, LSE, London, 28-29 Nov 2013
• Oxford Undergraduate Physics Conference 2013, 'A Century of Cosmic Ray Physics', Invited speaker, sole student speaker, 16 April 2013
• MA Philosophy Conference, `Parity violation and the reality of space (handout)', Reading, UK, 16 Jan 2013
• Establishing the Philosophy of Cosmology, Conference 2: Is 'God' Explanatory?, Oxford University, 9-11 Jan 2013

2012

• VSNU Student Research Conference 2012, 'Parity violation and the reality of space (poster)', Utrecht,  the Netherlands, 21 Nov 2012
• Corpus Christi College MCR/SCR Seminar, `Galactic Sources of Ultrahigh-energy Cosmic Rays (slides)', Oxford University, 12 Oct 2012
• Summer School and Workshop on the Standard Model and Beyond, European Institute for Sciences and their Applications, Corfu Summer Institute, Greece, 8-17 Sept 2012
• Summer School: History and Philosophy of Science: Revolutions in Science, Utrecht University, the Netherlands, 27-31 Aug 2012
• Establishing the Philosophy of Cosmology, Conference 1: The Arrow of Time, Oxford University, 30 Apr - 2 May 2012
• Oxford Undergraduate Physics Conference 2012, `Yang, Lee & Wu: Symmetries in Physics & CP-violation', Invited speaker, sole student speaker, 17 April 2012
• Seeking Wisdom Conference: Science & Religion, Oxford, 16-17 March 2012

2010

• International Conference on Global Water Issues (organiser), Association for European Integration AEGEE-Groningen, Groningen, the Netherlands, 15-19 Dec 2010
• International Conference on European Drug Policy (organiser), Association for European Integration AEGEE-Groningen, Groningen, the Netherlands, 15-22 May 2010