Month: July 2022

Fifty years of ‘More is different’

Steven Strogatz, Sara Walker, Julia M. Yeomans, Corina Tarnita, Elsa Arcaute, Manlio De Domenico, Oriol Artime & Kwang-Il Goh 
Nature Reviews Physics (2022)

August 1972 saw the publication of Philip Anderson’s essay ‘More is different’. In it, he crystallized the idea of emergence, arguing that “at each level of complexity entirely new properties appear” — that is, although, for example, chemistry is subject to the laws of physics, we cannot infer the field of chemistry from our knowledge of physics. Fifty years on from this landmark publication, eight scientists describe the most interesting phenomena that emerge in their fields.

Read the full article at: www.nature.com

Biological Robots: Perspectives on an Emerging Interdisciplinary Field

Biological Robots: Perspectives on an Emerging Interdisciplinary Field
D. Blackiston, S. Kriegman, J. Bongard, M. Levin
Advances in science and engineering often reveal the limitations of classical approaches initially used to understand, predict, and control phenomena. With progress, conceptual categories must often be re-evaluated to better track recently discovered invariants across disciplines. It is essential to refine frameworks and resolve conflicting boundaries between disciplines such that they better facilitate, not restrict, experimental approaches and capabilities. In this essay, we discuss issues at the intersection of developmental biology, computer science, and robotics. In the context of biological robots, we explore changes across concepts and previously distinct fields that are driven by recent advances in materials, information, and life sciences. Herein, each author provides their own perspective on the subject, framed by their own disciplinary training. We argue that as with computation, certain aspects of developmental biology and robotics are not tied to specific materials; rather, the consilience of these fields can help to shed light on issues of multi-scale control, self-assembly, and relationships between form and function. We hope new fields can emerge as boundaries arising from technological limitations are overcome, furthering practical applications from regenerative medicine to useful synthetic living machines.

Read the full article at: arxiv.org

Conway’s Game of Life: Mathematics and Construction

Nathaniel Johnston and Dave Greene

This book provides an introduction to Conway’s Game of Life, the
interesting mathematics behind it, and the methods used to construct
many of its most interesting patterns. Lots of small “building
block”-style patterns (especially in the first four or so chapters of
this book) were found via brute-force or other computer searches, and
the book does not go into the details of how these searches were
implemented. However, from that point on it tries to guide the reader
through the thought processes and ideas that are needed to combine
those patterns into more interesting composite ones.

While the book largely follows the history of the Game of Life, that
is not its primary purpose. Rather, it is a by-product of the fact
that most recently discovered patterns build upon patterns and
techniques that were developed earlier. The goal of this book is to
demystify the Game of Life by breaking down the complex patterns that
have been developed in it into bite-size chunks that can be understood
individually.

More at: conwaylife.com

A Novel Approach to the Partial Information Decomposition

Artemy Kolchinsky

Entropy 2022, 24(3), 403

We consider the “partial information decomposition” (PID) problem, which aims to decompose the information that a set of source random variables provide about a target random variable into separate redundant, synergistic, union, and unique components. In the first part of this paper, we propose a general framework for constructing a multivariate PID. Our framework is defined in terms of a formal analogy with intersection and union from set theory, along with an ordering relation which specifies when one information source is more informative than another. Our definitions are algebraically and axiomatically motivated, and can be generalized to domains beyond Shannon information theory (such as algorithmic information theory and quantum information theory). In the second part of this paper, we use our general framework to define a PID in terms of the well-known Blackwell order, which has a fundamental operational interpretation. We demonstrate our approach on numerous examples and show that it overcomes many drawbacks associated with previous proposals

Read the full article at: www.mdpi.com