The Physics of Decision-Making: Carlo Rovelli at the 6th FQXi Meeting

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But why? And does the fact that the universe started in a low entropy state play a role in providing the answer?

Elsewhere on the blog, Ian Durham has been writing about his own model of free will, which he presented at the 6th FQXi meeting, in Tuscany. Physicist Carlo Rovelli of Aix Marseille University in France has also been thinking in about the science of how we make decisions, but from a different angle, which brings in mysteries about thermodynamic entropy, as well as aspects of biology and psychology. You can listen to his full talk, which is now up on the podcast.

Rovelli begins by addressing whether agency can in fact be described in purely physical terms -- using just the science that we know about the world today. A few of the researchers speaking at the meeting, Paul Davies for instance (whom you'll hopefully hear more about in a later post), think that understanding the origin of life and consciousness, and in turn agency, will require new physics. Rovelli disagrees, and though he cannot yet give a blueprint that describes the mechanism behind our decision-making processes (which is a tall order, to be fair), he has begun to pose the scientific questions he feels need to be addressed along the way.

If you've read Kate Becker's fascinating article "First Things First: The Physics of Causality" then you already know something of the path that Rovelli is taking. He notes that decision-making is intimately tied to time's arrow; the choices we make now should be based on what happens in the past, and affect the future. Time's arrow is linked by many physicists to the idea that the entropy of the universe is increasing, although why the cosmos started in a low entropy state is tough to explain. So understanding the origin of causality is crucial, and Rovelli is attempting to do that by relating the concept of entropy in information theory to natural selection.

Agency also involves intention, says Rovelli, and the emergence of the first person perspective psychologically. If you want to know more about the work Rovelli has done so far and the open questions that he says still need to be addressed, then you could do worse than to decide to listen to the full version of his talk: "The Meaning of Meaning in the Natural World."