Jack is a doctoral student at Western University supervised by Professor Wayne Myrvold. Jack is originally from the United Kingdom, where he obtained a first class combined masters degree in Physics and Philosophy from the University of Oxford. His research interests are in the philosophy of physics, specifically in issues around probability, statistical mechanics, and the arrow of time. He is currently focused on researching the relationship between probabilities and nonlocal constraints within physics, pursuing the idea that a proper understanding of how the former affects the latter will shed light on ongoing debates in quantum mechanics. During his undergraduate degree, he worked on time travel and the impact that ability to time travel has on the probability distributions usually found in physics. When not working on his research, Jack writes science fiction.
My current interest lies in the foundations of physics, with a special emphasis on the role of probability and the relationship between probability and nonlocality constraints within physics.
My master’s thesis explored this topic via the issue of time travel. That time travel leads to nonlocal constraints is demonstrated by the fact that spacetimes containing closed timelike curves (trajectories that permit time travel, the existence of which current physics cannot rule out) must be fully consistent with themselves. This is famously exhibited by the grandfather paradox: Johnny goes back in time and attempts to kill his grandfather. The fact that he must fail constrains the totality of events which exist across the spacetime in a nonlocal way. That these nonlocal constraints have a profound effect on probabilities within the spacetime, I think, cannot be doubted. I thus argued that basic assumptions about the probabilistic behaviours of systems will place upper bounds on the likelihood certain kinds of time travel scenario every occuring. In this manner, I argued, the consistency constraints modify probabilities from those applicable in the absence of such constraints.
My intention is to apply similar reasoning to other issues within physics in my doctoral research, exploring the effect that other nonlocal constraints have on probability distributions within a given spacetime. For example, I plan to explore how the enforcement of isolation on systems can impact probability distributions on the way those systems go on to interact with their environments. An obvious application of this research will be Bell-inequality violations. These purport to demonstrate that no entirely local hidden variable theory can reproduce the same probability distributions as quantum mechanics. This appears to show that, as with cases of time travel, our world is subject to certain nonlocal constraints. I aim to investigate how such nonlocal constraints might be shown to modify the probability distributions expected of a local hidden variable theory to those exhibited by quantum mechanics.
I expect this research to make heavy contact with retrocausal and superdeterministic approaches to quantum mechanics. Furthermore, in the course of my research, I hope to help elucidate the ongoing
project of understanding time-asymmetry and equilibration from within statistical mechanics. This asks why it is possible to infer the behaviour of physical systems towards the future (we always know that they will reach a specific state of equilibrium) but not towards the past (we generally do not know what systems’ past states were, especially once they have reached equilibrium). The role of certain statistical assumptions in capturing this time asymmetry is clear, and understanding the grounds for these assumptions will do much to demystify the role of time in physics and more generally.
Jack Johnson, (2018), “The Utility of Idle Explanations”, British Journal of Undergraduate Philosophy 12(1) — Presented at 2018 BJUP annual conference.
Jack Johnson, (2019), “Probability and Coincidence in Time Travel Scenarios” (Masters Thesis), Phil Sci Archive: http://philsci-archive.pitt.edu/17695/ -Awarded Elizabeth Anscombe prize for best undergraduate philosophy thesis
Science, Knowledge, and Issues in Defence, UK Ministry of Defence, Berkshire, Co-hosted and moderated fortnightly debate society, giving extended topic introductions.
British Journal of Undergraduate Philosophy Annual Conference, London School of Economics, UK. Title: “The Utility of Idle Explanations”.
EF Academy Oxford Philosophy Society, EF Academy, Oxford, UK. Title: “To what extent can science give us knowledge of reality?”