Event Detail

Thu Mar 14, 2024
Howison Library
4–6:15 PM
Townsend Visitor
Jenann Ismael (Johns Hopkins University)
Quantum Mechanics: A Participatory Universe in a Realist Mode

Most day-to-day physics involves modelling other systems: cells, gases, fluids. In those contexts, we maintain a provisional separation of subject and object, or of investigator and system being investigated. When we are dealing with the universe as a whole, we are part of the subject matter, but we tend to adopt a god’s eye view, treating the universe imaginatively as though it were an object we were looking at the universe from the outside.

This is a convenient and mostly harmless fiction but it pushes out of view a phenomenon that I’m going to call interference. Interference arises because we are part of the universe. That means that our representational activity is connected in the domain that we are representing and it is going to be impossible to stabilize some facts or events in the world independently of the act of representing them. This fact turns out to be important in some philosophically contested contexts. I’ll be exploring its fallout.

Lecture 3 – Quantum Mechanics: A Participatory Universe in a Realist Mode

Interference is inevitable for a system representing the world from within. How it propagates, however, depends on the physics of the domain in which it is connected. Seeing how it plays out in classical and quantum mechanics gives us a new way of understanding the differences between them. In the first talk, I suggested that in a classical setting against the background of a thermodynamic gradient, interference is focused and channeled into the future. I will argue here that in quantum mechanics, below the Planck scale interference is endemic. This provides a clear sense in which the universe is participatory. Most interpretations that have recognized the participatory character of quantum interactions have advocated epistemic interpretations (i.e., have construed the quantum state as representations of knowledge). I’ll explore ways of understanding it in a realist mode.