The Metaphysics of Black Holes Workshop – September 12 2022

The FraMEPhys project will host a workshop on The Metaphysics of Black Holes on Monday 12 September 2022, at the University of Birmingham’s Edgbaston campus in the Teaching and Learning Building room 202.

Registration is now open here.

If you have any queries about this event, please email


Sam Baron (Australian Catholic University)

Baptiste Le Bihan (University of Geneva)

Nikk Effingham (University of Birmingham)

Katie Robertson (University of Birmingham)

Alastair Wilson (University of Birmingham)


Teaching and Learning Building, room 202 (campus map)
University of Birmingham
Pritchatt’s Road
Birmingham B15 2TT


Monday 12 September

09.45-10.45: Baptiste Le Bihan
“Prolegomena to a metaphysics of black holes”

11.00 -12.00: Katie Robertson
“Black Hole Thermodynamics: A Crisis of Identity”

13.15 -14.15: Nikk Effingham
“Eternal Sunshine of the Spotlight Kind”

14.30 -15.30: Alastair Wilson
“The Time-Travelling Interventionist”

16.00 -17.00: Sam Baron & Baptiste Le Bihan
“Trouble on the Horizon for Presentism”


Sam Baron (Australian Catholic University) and Baptiste Le Bihan (University of Geneva)
“Trouble on the horizon for presentism”
Surface presentism is the combination of a general relativistic physics with a presentist metaphysics. In this paper, we provide an argument against this combination based on black holes. The problem focuses on the notion of an event horizon. We argue that the present locations of event horizons are ontologically dependent on future black hole regions, and that this dependence is incompatible with presentism. We consider several responses to the problem available to the surface presentist, and argue that none succeed. Surface presentism thus faces the prospect of refutation based on evidence that confirms the existence of black holes. We finish by offering a strategy for generalising the black hole argument to other global properties of spacetime.

Baptiste Le Bihan (University of Geneva)
“Prolegomena to a metaphysics of black holes”
The existence of black holes has been predicted by general relativity and confirmed by astronomical data. But other theories offer a different understanding of their nature. Considering this situation, I investigate the conditions of possibility for a metaphysics of black holes. To arrive at educated guesses about their metaphysical nature, I propose to look for conceptual invariants in three theories that have a special relation with black holes: general relativity, semiclassical gravity and string theory. I use this methodology to tackle two questions. First, what is the ontological category of black holes: are they objects, regions of spacetime or both? Second, more generally, can the existence of black holes reveal anything insightful about the nature of ontological categories?

Katie Robertson (University of Birmingham)
“Black Hole Thermodynamics: A Crisis of Identity”
Do black holes expand for the same reason that cups of tea cool down? There is a striking similarity between the laws of black hole mechanics and the laws of thermodynamics; so striking, that some have gone as far as — indeed the orthodoxy in theoretical physics is — to say it is an identity. But others point out differences between the quantities associated to black holes and the quantities of ordinary thermal systems, like cups of tea and boxes of gas. How can we say black hole entropy is thermodynamic entropy when there are these differences? In this paper, I show to what extent the increasingly popular tool of functionalism can be used to understand the claim that SBH is STD.

Alastair Wilson (University of Birmingham)
“The Time-Travelling Interventionist”
Interventionist treatments of causation and grounding are deservedly popular, but they run into difficulties in prospective cases of dependence loops – for example, in models of general relativity which feature closed timelike curves. I explore some ways of generalizing the interventionist machinery to account for cases of dependence loops of both the causal and non-causal varieties, drawing on my recent account of the difference between grounding and causation in terms of the principles mediating the dependency,