Session 9 Abstracts

Time, Physics and Experience

  • 10:30–11:00 Sam Baron - The Causal Theories of Time
  • 11:00–11:30 Peter Evans - A Physical Basis for Manifest time?
  • 11:30–12:00 Patrick Dawson
  • 12:00–12:30 Jules Rankin - What Kind of Phenomenon is Flow?

Organiser: Jules Rankin

The University of Sydney

This session will examine a variety of issues surrounding the nature and metaphysics of Time in the light of Physics and Experience. How should new and old results from physics inform our metaphysics of time? How should our subjective experience of time also inform said metaphysics? Speakers in this session will examine these questions from a variety of perspectives. 

Sam Baron will be presenting work examining recent developments in fundamental physics to advocate a causal theory of time. While causal theories of time have received philosophical push-back in the past, these new developments from Quantum Gravity provide good reason to reexamine this approach of which Sam provides a defence. 

Peter Evans will be presenting work examining the relationship between notions of ’physical time’ and ’manifest time’ and showing how the apparent conflicts between these two notions can in fact be reconciled. To do so Peter re-examines our understanding of clocks and the relation between agents and the world. 

Jules Rankin will be presenting work examining the flow, or passage of time in terms of a phenomena. Jules discusses the two broad ways in which phenomena have been understood in the philosophical literature, as objective features of the world or as features of subjective experience, and applies them to the case of temporal flow. 

Finally, Patrick Dawson will be presenting work describing a way of understanding quantum mechanics in the light of a presentist perspective. One of the main consequences of this perspective is that both the future and past can be thought of as open, in sense that one can only describe what has/will happen using a range of probabilities. 

The Causal Theories of Time 

Sam Baron 

Dianoia Institute of Philosophy

The causal theory of time has its roots in Leibniz’s relationalist theory of temporal succession. For Leibniz, each successive time is causally explained by the last. In the 20th Century, the causal theory of time gives way to the causal theory of spacetime. Theorems provided by Hawking and Malament suggest that the metric structure of general relativity can be recovered from a simple causal topology. This leads to a renaissance for the causal theory in the work of Reichenbach, Grunbaum and then Van Fraassen. The causal theory subsequently comes under heavy fire from Smart and Earman. This leads to a widespread abandonment of the view within philosophy. Meanwhile, in physics, the results of Hawking and Malament live on, forming the core of a new approach to physics: causal set theory, which promises to yield a quantum theory of gravity. The abandonment of the causal theory in philosophy thus appears premature. I therefore suggest a return to the causal theory of spacetime. I show how to rebuild it using notions of fundamentality and argue that the resulting view avoids the purely philosophical difficulties that more traditional causal theories face. 

I am an associate professor of philosophy at the Australian Catholic University. I work primarily in the metaphysics of science, focusing on the nature of time and the existence of mathematical objects. I’ve published widely on these topics, in journals such as Mind, Journal of Philosophy, Philosophy and Phenomenological Research, Philosophers’ Imprint, Philosophical Quarterly, Philosophical Studies and The British Journal for the Philosophy of Science. I currently hold two ARC grants to support my research. A DECRA, focusing on timelessness in physics and philosophy, and a Discovery Project, focused on reconciling the manifest and scientific images of time. I have a book forthcoming with Oxford University Press titled Out of Time, which is co-authored with Kristie Miller and Jonathan Tallant, and which focuses on the idea that time does not exist. 

A physical basis for manifest time?

Peter Evans 

School of Historical and Philosophical Inquiry, The University of Queensland 

An all too common claim in the philosophy of time is that time as we find it represented in physics – ‘physical time’ – is in conflict with our experience of time – ‘manifest time’. The three features of manifest time at the core of this claim are (i) the past is fundamentally different from the future, (ii) the present moment is special, and (iii) time flows. In this talk I set out an argument that this apparent conflict between physical time and manifest time is no conflict at all. Firstly, I claim that we have been looking to the wrong parts of physics as our guide to the nature of time. Secondly, I claim that the apparent conflict fails to acknowledge the relational nature of time, and the fact that physical clocks are open dissipative systems subject to noise. And, thirdly, I claim that agents modelled as ‘learning machines’ are just such physical clocks. I speculate on the ramifications of this argument, including for traditional approaches to the philosophy of time. 

Pete is currently a UQ Amplify Lecturer specialising in the philosophy of science, particularly the philosophy of physics. His research interests include time and causation in modern physics, especially quantum foundations, and the epistemology and methodology of science, especially analogue experimentation. He has recently completed an ARC Discovery Early Career Research Award project, “A philosophical exploration of simulating and controlling the quantum world”, which examines how a novel labora- tory technique, analogue quantum simulation, illuminates the epistemology of analogue experimentation. Pete’s philosophical research is informed by the latest experimental and theoretical results from the physical sciences. 

Patrick Maurice Dawson

School of History and Philosophy of Science, The University of Sydney 

Some of us share an intuition that the future is open, so that one can only describe what will happen using a range of probabilities. By contrast, the present seems to be closed and certain. There is uncertainty and openness in the world, in some sense, but by the time we witness events happening, there is just one fixed thing that happens. Meanwhile, in the world of quantum mechanics, we find that systems outside of measurement are modelled using, too, a range of probabilities. Measured systems, by contrast, are described by a single determinate state. At face value, this again suggests that there is uncertainty and openness in the world, but whenever we witness events happening, there is just one fixed thing that happens. 

In this talk I investigate how one might marry these notions, by interpreting the uncertainty we see in quantum theory as openness in action. The catch? One would need to believe that not only the future, but also the past, is open. I consider the merits of such an approach, which would require a presentist (or, at least, a distinctly A-theoretic) temporal worldview. In defending such an approach, I counter those who attempt to understand quantum mechanics without the A-theoretic elements that set its depiction of time apart from the depiction found in relativity theory. I argue that a privileged present and the passage of time, for example, play a useful role in interpreting quantum theory, and should not be lightly discarded. 

Patrick Dawson is a final-year PhD candidate at the University of Sydney. His background is originally in physics, which he studied as an undergraduate at the University of Otago, and in his masters at the University of Melbourne. Patrick has since moved into the world of philosophy, with his current research focusing on the interplay between modern physics and the philosophy of time. In particular, Patrick is interested in how our best physics might be understood and interpreted within A‑theoretic understandings of time, such as within Presentism. He has also written on other challenges facing the A-theories. In one recent example, he has defended radical solutions to the problem of presentist truthmaking in Hard Presentism (Synthese, 2020). 

What Kind of Phenomenon is Flow? 

Jules Rankin

University of Sydney

What is the nature of the flow, or passage of time? Is it grounded in an objective feature of the world, or is it grounded in the experiences of subjects? I cache out these questions in terms of phenomena. More specifically, in the various ways in which phenomena have been understood in the philosophical literature. So, what kind of phenomena is the flow of time? I explore two broad ways of characterising the phenomena of flow, either as an objective phenomena or subjective phenomena and see how each can be used to characterise flow. I point out that each characterization has it’s advantages and drawbacks and that after all is said and done, both characterisations leave much to be desired. In both cases one major hurdle is incorporating flow into our scientific realist image of the world. However, this need not necessarily be the case since the nature of time and its flow/passage bears upon current work in Quantum Gravity, so clarity on this question has the potential to generate insight for current issues in the fundamental physical sciences. I propose a tentative metaphysical solution to this dialectic may be found in the adoption of neutral monism and epistemic structuralism with regards to the products of scientific enquiry. 

Jules Rankin is a second year PhD candidate in the school of History and Philosophy of Science at the University of Sydney. Prior to this, he gained his BSc (Honours) in Physics, also at the University of Sydney. His current Phd research focuses on the understanding flow of time and how it relates to our scientific and manifest images of the world. To do so Jules has examined recent developments in the field of Quantum Gravity, such as recent work from Lee Smolin regarding reassessing the fundamentality of different features of time in our cutting edge physical theories.