Physicists have struggled for decades to reconcile general relativity with quantum mechanics. Doing so would deepen our understanding of black-hole formation, the earliest moments of the universe, and perhaps its ultimate fate. Yet, a unifying approach has not been found.
We believe the obstacle is a pervasive misconception of spacetime as objective and agent-independent. Inspired by participatory-realist approaches to quantum theory and philosophies of mind, we propose instead that spacetime emerges from the action–perception feedback loops of embodied agents. Our interdisciplinary collaboration in control theory, quantum foundations, and phenomenology aims to develop a compelling physical and philosophical case in support of this hypothesis, and to explore its implications for the question of whether spacetime should be quantized.
To do so, our research will address four incisive questions: for what purposes and under what constraints (if any) could quantum spacetime reconstruction prove more useful than classical estimation; can embodied, purposive strategies analogous to landmark-based navigation be lifted faithfully into the formalism of quantum reference frames; how can independent agents consolidate their personal experiences to develop a public consensus spacetime; and, what insights relevant to all of these can be gleaned from studying the unpublished “participatory universe” notebooks of John Archibald Wheeler?
By the end of the project we will deliver a portfolio of publications, presentations, meetings, and annotated digitizations of pages from the Wheeler archive, driving three long-term impacts for our work: to normalize the idea of spacetime as a purposive construct; to normalize a view of quantum theory as a tool for embodied agency; and to launch the development of a comprehensive online Wheeler archive. Together these impacts will radically shift the background assumptions of quantum gravity research and unlock pivotal new paths.
