TITLE: Computational Processes in Nature AUTHOR: Eugene Wallingford DATE: July 03, 2007 8:02 AM DESC: ----- BODY: Back in February I wrote a speculative piece on computer science as science, in which I considered ways in which CS is a scientific discipline. As a graduate student, I grew up on Herb Simon's book The Sciences of the Artificial, so the notion of studying phenomena that are contingent on the intentions of their designer has long seemed a worthwhile goal. But "real" scientists, those who study the natural world, have never been persuaded by Simon's arguments. For them, science deals with natural phenomena; programs and more comprehensive computer systems are man-made; and so computing as a science of the artificial is not a real science. As the natural sciences develop, though, we have begun to learn something that computer scientists have sensed for a long time: computational processes occur in the natural world. Peter Denning has taken dead aim on this observation in his new essay Computing is a Natural Science, published in this month's Communications of the ACM. He opens with his take-home claim:
Computing is now a natural science. Computation and information processes have been discovered in the deep structures of many fields. Computation was present long before computers were invented, but the remarkable shift to this realization occurred only in the last decade. We have lived for so long in the belief that computing is a science of the artificial, it may be difficult to accept that many scientists now see information processes abundantly in nature.
Denning supports his claim with examples from biology and physics, in which natural computations now form the basis of much of the science, in the form of DNA and quantum electrodynamics, respectively. In many ways, the realization that computation lies in the deep structures of many natural systems is a vindication of Norbert Wiener, who in the 1940s and 1950s wrote of information as a fundamental element of systems that communicate and interact, whether man-made or living. The article continues with a discussion of some of the principles discovered and explored by computer scientists, all of which seem to have correlates in natural phenomena. The table in his paper, available on his web site as a PDF file, lists a few key ones, such as intractability, compression, locality, bottlenecks, and hierarchical aggregation. That these principles help us to understand man-made systems better and to design better systems should not distract from their role in helping us to understand computations in physical, chemical, and biological systems. There is some talk on my campus of forming a "school of technology" into which the Department of Computer Science might move. From my department's perspective, this idea offers some potential benefits and some potential costs. One of the potential costs that concerns me is that being in a school of technology might stigmatize the discipline as merely a department of applications. This might well limit people's perception of the department and its mission, and that could limit the opportuniies available to us. At a time when we are working so hard to help folks understand the scientific core of computing, I'm not keen on making a move that seems to undermine our case. Explicating the science of computing has been Denning's professional interest for many years now. You can read more about his work on his Great Principles of Computing web site. There is also an interview with Denning that discusses some of his reasons for pursuing this line of inquiry in the latest issue of ACM's Ubiquity magazine. As Denning points out there, having computing as a common language for talking about the phenomena we observe in natural systems is an important step in helping the sciences that study those systems advance. That we can use the same language to describe designed systems -- as well as large interactive systems that haven't been designed in much detail, such as economies -- only makes computer science all the more worthy of our efforts. -----