It’s pretty easy to see that a rock and a squirrel are different. The rock doesn’t do much except slowly erode. A squirrel, on the other hand, is a flurry of activity. It endlessly scans its surroundings in search of food or danger. And when any of them appear, the chipmunk is quick to react. On a more fundamental level though, what really Yippee difference between an inanimate rock and a very alive chipmunk? What is the difference between Mathematical Physics and Chemistry level?
This question is at the heart of a three-day workshop on “Information-Driven States of Matter” that I’ll be co-hosting with Gourab Ghoshal and Artemy Kolchinsky next week at the University of Rochester. I’m really looking forward to the meeting, and today I want to give you a preview of some of the topics we’ll be exploring as they’re bound to form future columns.
Information Systems
Over the past few decades, physicists have increasingly come to view life as a unique “state of matter” that requires special attention. It began 70 years ago when Edwin Schrödinger wrote his seminal work, What is life? In that little book, he asked whether living systems might require the development of new laws of physics. Although this remains a contentious question, many scientists who study life as a “complex system” have come to believe that living systems are unique in at least one notable way: they use information.
While the rock we have just considered might be describable in terms of information (say, in the arrangement of its atoms), we are the ones describing it. The rock couldn’t care less about information. On the other hand, even an ordinary amoeba is adept at storing, copying, transmitting and processing information. Cells are not only adept at using information, but also dependent on it. In this sense, they are information-driven: They need to constantly acquire and use information from their environment to stay alive. It’s also worth noting that some physicists have used the term “active matter” to describe living systems, but the active part is actually about information.
In the workshop, we will look at our question about information systems from a broad perspective. On the largest scale, we want to understand life as an astrobiological phenomenon. To that end, we will host a talk by Caleb Scharf of NASA’s Ames Research Center. Scharf’s work explores the concept of “computational zones”. If life requires information processing, which regions of the universe have the physical conditions that make computations possible? In a similar vein, but looking in finer detail, Florida Institute of Technology’s Manasvi Lingam looks at the constraints (ie, limits) of the kinds of information processing that can occur in different planetary environments (e.g., hydrocarbon lakes on Titan, the largest moon of Saturn).
We will also explore the specifics of how life on Earth uses information. Since much of life’s computing machinery is based on chemistry, Harvard’s Juan Perez Mercader is setting out to unpack the connection between biochemistry and information processing. At least for humans, the brain is the CPU for information utilization. This is why Claremont Colleges’ Sarah Marzen will be asking how well neural systems of any kind (including artificial ones) can make predictions (like those needed to stay alive in changing environments). Jordi Pinero, a post-doc in our own collaboration, will investigate how information processing needs can actually limit the growth of organisms.
However, no progress can be made in this field without the development of new and powerful mathematical tools that combine information theory with the physics, chemistry, and biology of complex science. To that end, David Wolpert of the Sante Fe Institute takes a deep dive into the non-equilibrium statistical physics of computation and communication. His work pushes the boundaries of what we mean when we talk about physics and information. And because the kind of information you use is as important as using all of it, Damian Sowinski from our own group in Rochester will conduct a workshop studying semantic information, i.e. the importance of meaning.
This is just a sample of the ideas we’ll be learning, discussing, and arguing about (scientists love to argue). I cannot tell you how much I am looking forward to this workshop. I hope that we will come away with a new and better view of this powerful question that Schrödinger asked so long ago: What is life?
By the way, I’m planning to live-tweet (or live-X-ing, or whatever it’s called these days) the workshop at @adamfrank4 if you want to watch it (July 10-12). Many thanks also to the Templeton Foundation for sponsoring the meeting.