The Mysterious Molecular Structures Found in City Layouts

Did you know that, from the air, the arrangement and structure of Boston's buildings, and the positioning of those buildings relative to one another, looks a lot like the molecular structure of an "amorphous liquid"? Seattle and L.A. do, too. Chicago, with its rigid grid system, apparently looks like glass.

Above: Boston, from above, two days after Winter storm Nemo

So says Franz-Josef Ulm, engineering professor at the Massachusetts Institute of Technology. Writing for the Boston Globe, Ruth Graham explores whether Ulm's newly minted field of "urban physics" stands up to scientific scrutiny:

So far, Ulm says, the work has two potential applications. First, it could help predict and mitigate urban heat island effects, the fact that cities tend to be several degrees warmer than their surrounding areas—a phenomenon that has a major impact on energy use. (His research on how this relates to structure is currently undergoing peer review.) Second, he says that cities' molecular order (or disorder) may also affect their vulnerability to the kinds of catastrophic weather events that are becoming more frequent thanks to climate change.

Are materials and metropolises really comparable? And if so, is the comparison useful as more than a metaphor? The urban planning community, which has its roots in the design world, has historically been wary of science's attempts to capture the incredible complexity of the urban environment. (In her classic 1961 book "The Death and Life of American Cities," Jane Jacobs lambasted modern urban planning itself as a "pseudoscience," in which "years of learning and a plethora of subtle and complicated dogma have arisen on a foundation of nonsense.")

But it is warming to these efforts. Today scientists are some of the leading investigators of urban design issues. "There have been ideas about cities since Aristotle and Plato," said Luis Bettencourt, professor of complex systems at the Santa Fe Institute. "But the ways we can measure cities, test ideas, and compare cities across time and place and size has become so much more possible, that we can now test those ideas." Bettencourt, who was trained as a theoretical physicist, published a paper in Science last summer proposing a new quantitative framework for understanding cities: They are a unique complex system, he argues, with predictable social, spatial, and infrastructure properties.

More at The Boston Globe.