BenKoski's blog

I saw this article on Slashdot today touting the "first digital simulation of an entire life form," and couldn't help but think of the Karl Sims' "evolved virtual creates" that we saw a few weeks ago during our discussion of evolutionary algorithms. Though the mechanisms and scale of simulation are wholly different (Sims, as I understand it, worked with locomotion mechanisms, while these researchers worked on the cellular level)--the resulting "life forms" existing only in virtual space are quite similar in concept. The premise of both experiments is also remarkably similar in that both groups believed that they could effectively simulate organic life forms using computer algorithms.

As I was drafting my comment here in response to PG's blog entry, another thought (irrelevant to PG's thread) occurred to me: Is there an agent in a CA? We all know that a defining characteristic of a CA (or an emergent system) is that there is no conductor or director. But what about an agent? What is "doing" a CA? Is the computer the agent? If you read Wolfram's formal definition of a CA, you might begin to think that the rules are the agent. The rules themselves might be the "dynamically interacting rule-based agents" (funny concept there...are CA rules fundamentally "rule-based""?) that are the hallmark of an agent-based model. If so, aren't CAs just a subset of agent-based models?

While paging through Tripod last week in search of a book for the upcoming book review project, I noticed something very interesting: "emergence" is not considered a valid subject, at least in the eyes of the bibliographers who maintain the official Library of Congress subject headings. Even though the books on the suggested reading list all ostensibly represent perspectives on emergence, they are classified under a wide swath of subject headings ranging from "Graph Theory" and "Network Analysis" to "Complexity (Philosophy)" that never include any reference to "emergence." Even Wolfram's A New Kind of Science mentions nothing of emergence in its subject classifications: as far as the Library of Congress is concerned, it is merely a book about cellular automata and computational complexity. Though I know that LC headings frequently fail to capture the full thrust of a book's argument, I think that it's clear that Wolfram's work is about something more than just computation or CA.

Based on what was said during the first day of class, I understand emergence to be the study of complex systems in which the final outcome for the system is determined by the state of a multitude of variables that interact in complex, unpredictable, and chaotic ways. As a Cities major concerned primarily with issues of planning and policy in modern American cities, my interest in emergence lies mainly in using the concept to understand cities as the product of large numbers of independent and unpredictable actors. For instance, one could view cities as a collection of a large number of individual citizens, or a large collection of economic agents and actors, or a large set of built structures--all of which represent examples of emergence theory that could be used to define a city. Thinking about cities as emergent systems raises intriguing opportunities to use these insights about cities as systems to model, simulate, and predict changes in the urban system to support planning decisions.