Luca Gasparinetti
Università della Svizzera italiana
“Does causation play a role in fundamental physics? Generally, it has been argued in several places that causation does not play any legitimate role in fundamental physical theories. Based on recent developments in cutting-edge physics, I will show that this tradition can be reinvigorated with a novel challenge. I will call it the timeless challenge. As I will present it in more detail, the challenge roughly proceeds as follows. It is widely accepted that in approaches to the most fundamental (cur- rently available) theory called Quantum Gravity (QG), time is not fundamental. Hence, since causal relations are typically anchored in temporal relations, one might conclude that along with temporal relations, causal relations are not fundamental. Therefore, there is no fundamental causation in approaches to the most fundamental physical theory.
This conclusion, at least prima facie, faces opposition from approaches that either (i) reject that causal relations require the existence of temporal relations or (ii) take time and causation as fundamental. Causal Set Theory belongs to the first group (e.g., Baron and Le Bihan, 2023; Wüthrich, 2023). Causal Quantum Histories (Markopoulou, 2000), (Quantum) Energetic Causal Set Models (e.g., Cortês and Smolin, 2014), and Causal Dynamical Triangulations (e.g., Ambjørn, Jurkiewicz and Loll, 2012) belong to the second one.
In this talk, I will provide a first assessment of the role of causation and its relation to time in QG, by considering those theories that make an explicit reference to the term ‘causation’. More specifically, I will address the alleged role played by causation in Causal Set Theory (eventually in one of its alleged quantum versions) and Causal Dynamical Triangulations. Despite the fact that physicists explicitly appealing to causation in these theories may sound great to the ears of those who believe that causation can be anchored in fundamental physics, I will suggest that the cases of Causal Set Theory and Causal Dynamical Triangulation are respectively less convincing and less significant than one might expect.
I will eventually conclude by mentioning some interesting further developments concerning causation and QG. As an example, I will mention that (Quantum) Energetic Causal Set Models might furnish the ground for reinvigorating the discussion around a novel version of process theories of causation akin to Dowe’s conserved quantity theory (e.g., Dowe 2000). I will also sketch a brief argument that concerns the causal theory of property: (i) People maintained that entangled states can be treated as powers. (ii) Entangled states must feature in any theory of QG. (iii) Therefore, if entangled states can be treated as powers then causation might play a role in all theories of QG in the form of causal properties.”
Chair: Niklas Parwez
Time: September 11th, 13:30 – 14:00
Location: SR 1.004, online
SOPhiA 2026 