Complexity_ A Guided Tour - Melanie Mitchell [144]
Like the research program of the cyberneticists, these ideas are very appealing, but attempts to construct a rigorous mathematical framework—one that explains and predicts the important common properties of such systems—were not generally successful. However, the central scientific questions posed by these efforts formed the roots of several modern areas of science and engineering. Artificial intelligence, artificial life, systems ecology, systems biology, neural networks, systems analysis, control theory, and the sciences of complexity have all emerged from seeds sown by the cyberneticists and general system theorists. Cybernetics and general system theory are still active areas of research in some quarters of the scientific community, but have been largely overshadowed by these offspring disciplines.
Several more recent approaches to general theories of complex systems have come from the physics community. For example, Hermann Haken’s Synergetics and Ilya Prigogine’s theories of dissipative structures and nonequilibrium systems both have attempted to integrate ideas from thermodynamics, dynamical systems theory, and the theory of “critical phenomena” to explain self-organization in physical systems such as turbulent fluids and complex chemical reactions, as well as in biological systems. In particular, Prigogine’s goal was to determine a “vocabulary of complexity”: in the words of Prigogine and his colleague, Grégoire Nicolis, “a number of concepts that deal with mechanisms that are encountered repeatedly throughout the different phenomena; they are nonequilibrium, stability, bifurcation and symmetry breaking, and long-range order … they become the basic elements of what we believe to be a new scientific vocabulary.” Work continues along these lines, but to date these efforts have not yet produced the coherent and general vocabulary of complexity envisioned by Prigogine, much less a general theory that unifies these disparate concepts in a way that explains complexity in nature.
Five Questions
As you can glean from the wide variety of topics I have covered in this book, what we might call modern complex systems science is, like its forebears, still not a unified whole but rather a collection of disparate parts with some overlapping concepts. What currently unifies different efforts under this rubrik are common questions, methods, and the desire to make rigorous mathematical and experimental contributions that go beyond the less rigorous analogies characteristic of these earlier fields. There has been much debate about what, if anything, modern complex systems science is contributing that was lacking in previous efforts. To what extent is it succeeding?
There is a wide spectrum of opinions on this question. Recently, a researcher named Carlos Gershenson sent out a list of questions on complex systems to a set of his colleagues (including myself) and plans to publish the responses in a book called Complexity: 5 Questions. The questions are
Why did you begin working with complex systems?
How would you define complexity?
What is your favorite aspect/concept of complexity?
In your opinion, what is the most problematic aspect/concept of complexity?
How do you see the future of complexity?
I have so far seen fourteen of the responses. Although the views expressed are quite diverse, some common opinions emerge. Most of the respondents dismiss the possibility of “universal laws” of complexity as being too ambitious or too vague. Moreover, most respondents believe that defining