In this talk, we will have a quick summary of scaling theory's applications in physics, biology, and social science. In particular, I will elaborate on urban scaling and its relation to the universality and self-similarity lurking in the urban systems. The universality and self-similarity of various urban phenomena seem both trivial and non-trivial. On one hand, the dynamics of cities are so complex, entangled with geographic factors and idiosyncratic historical paths, that it is inconceivable to explain them in a simple way, and thus even a well-designed plan often results in unintended consequences. This high level of complexity contradicts the universality and self-similarity that we surprisingly observe in almost every property of cities (population distribution, crime rate, productivity and even economic diversity). On the other hand, universality is a natural, even trivial, consequence from a common set of functionalities of cities. Fundamental units, people, are biologically not so much different from each other. In addition, people share reasons to be attracted to cities: more interaction, greater opportunity, higher productivity, and better infrastructure. These basic dynamics of urbanization is manifested as a strong signal of universality and self-similarity under a single scaling law.
Professor Hyejin Youn, Northwestern University
Host: István Kovács
Keywords: Physics, Astronomy, Complex Systems