Prof. Sam Fletcher at the Wilson Lecture Series/ECE fall 2022 Colloquium

Physical computation

What makes something a computer? We are familiar with computational artifacts--devices made by people--but are there any "natural" computers? Many neuroscientists maintain that the brain is in fact a computer, so that we should explain its workings in computational terms. Some biologists explain phenomena as diverse as cell dynamics, swarming behavior, and slime mould foraging as computational. Many of these tacitly employ a "simple mapping account" which holds that any phenomena that can be modeled ("mapped") as a Turing machine or some equivalent notion is a computer. But this account wildly overgeneralizes, allowing almost any physical thing of sufficient complexity to be a computer, thereby threatening to rob computational explanations of their power. After reviewing the problems that various amendments to the simple mapping account face, I suggest a quite different account: what makes something a computer is how an agent uses the thing. Finally I draw some lessons from this agent-centric view for computational explanations in the natural world.

About Professor Sam Fletcher

Sam Fletcher is Associate Professor in the Department of Philosophy at the University of Minnesota Twin Cities, a Resident Fellow of the Minnesota Center for Philosophy of Science, and an External Member of the Munich Center for Mathematical Philosophy, Ludwig-Maximilians-Universität.

Start date
Thursday, Nov. 3, 2022, 4 p.m.