Jonathan Fay
PhD student in the Philosophy of Physics.
About me
Coming from a background in Natural Sciences and Physics, I transferred to philosophy of physics to pursue foundational questions more deeply and with more freedom.
I am currently a doctoral candidate at the University of Bristol, UK. My doctoral advisors are Karim Thébault and James Ladyman. From April to August 2024, I was visiting the Lichtenberg group for the History and Philosophy of Physics at the University of Bonn as a Heinrich Hertz Fellow.
Thesis
The thesis is primarily a reexamination of the foundations of relativity theories, in particular, through a discussion of “Mach’s principle“, it’s philosophical justification and it’s physical consequences if realised in a gravito-inertial theory. I also touch on fundamental issues in the philosophy of space and geometry, recovering a little known argument by Joseph Delboeuf in defence of a form of Euclidean apriorism. My philosophical stance combines rationalist and empiricist elements; more broadly I hope to help reaffirm the rational basis of post-classical physical theories, and thereby revive an older style of scientific investigation that combines philosophical and empirical investigation to make progress in theoretical physics.
Some influences
Henri Poincaré, Joseph Delboeuf, Ernst Mach, Dennis Sciama, Hermann Weyl, Julian Barbour, Immanuel Kant, Arthur Schopenhauer.
Talks
Lost in Translation, March 2026
Delboeuf’s forgotten defence of Euclidean geometry
Sevilla
Ontologia, October 2025
Why does nature conform to laws?
San Sebastian
Foundations, 30 June 2025
On Reissner’s hypothesis
Gdańsk, University of Gdańsk
PAMO, June 2025
Reissner’s hypothesis
Youtube recording of the talk
Munich
UPAC colloquium, 04/03/2025
On Reissner’s hypothesis
Utrecht, Utrecht Uni
PoP-grunch, 30/01/2025
On Reissner’s hypothesis
Oxford, Oxford Uni
iHPS Bristol August 2024
On Reissner’s hypothesis
Bristol, Bristol Uni
Historical epistemology of the final theory program seminar, 10/07/2024
On the Reissner-Sciama hypothesis
Hybrid Berlin, MPIWG
Machian Gravity workshop, 15/06/2024
Mach’s principle, Mach’s hypothesis and Reissner’s hypothesis
Bonn, Hotel Europa
Phil and Phys network meeting, 31/05/2024
On the relativity of magnitudes
Wuppertal, Wuppertal Uni
HPPRS (Summer), 28/05/2024
On the Reissner-Sciama hypothesis
Hybrid Bonn, Uni Bonn
BBLOC workshop, 2023
On the Relativity of Magnitudes
London, KCL
UoB Philsoc, 2023
A Shape Without a Size
Bristol, pub
BBLOC workshop, 2022
In Defence of Flat Space
London, KCL
PoP-grunch, 2021
Absolute Space Reconsidered
Online, Oxford Uni
PoP-grunch, 2020
Towards a Machian Theory of Gravity
Online, Oxford Uni
Relative Motion 