Saturday, July 6, 2013

Cities, stars, entropy, and sustainability

Discovery News inspired me to examine the connections among all these topics by posting Cities Are Like Stars.

People living in big cities have a lot in common with... the inside of a star? Sounds crazy, but it actually makes sense. Anthony explains this radical new way to look at life in the world's busiest cities.
That's such a good explanation of how cities work as systems that I'm considering showing it to my students as part of my urbanization and population lecture.  As for the central idea, here's the money quote from the EurekAlert press release describing the research.
So what is a city? Bettencourt thinks the only metaphor that comes close to capturing a city's function is from stellar physics: "A city is first and foremost a social reactor," Bettencourt explains. "It works like a star, attracting people and accelerating social interaction and social outputs in a way that is analogous to how stars compress matter and burn brighter and faster the bigger they are."
So cities are like stars because as both get larger, both increase their metabolisms.  As Spock would say, fascinating.  Unfortunately, if one extends the metaphor farther, the implications become ominous.  Large stars burn bright, but don't live very long.  Therefore, if a city really is like a star, being large will doom it to a short life.

Kunstler might appreciate that conclusion, as he's thought that industrialism, which allows modern cities, sows the seeds of its own destruction through its ruthless quest for efficiency.
Industrialism is an entropic project. It accelerates and intensifies entropy, which is to say the drive toward disorder and death.
The same week that the press release and video were issued and posted, Kunstler repeated his dire warning by more explicitly connecting entropy and the decline of large cities and their suburbs.
Gasoline is now too expensive to run the suburban living arrangement. It will remain marginally unaffordable. Even if the price of oil goes down, it will be because citizens of the USA will not have enough money to buy it. Lesson: the suburban project is over, along with the economy it drove in on.

But so is the mega-city project, the giant metroplex of skyscrapers. So, don’t suppose that we can transform the production house-building industry into an apartment-building industry. The end of cheap oil also means we can’t run cities at the 20th century scale. That includes the scale of the buildings as well as the aggregate scale of the whole urban organism.
[E]ntropy never sleeps. Everything in America except the Apple stores and a handful of big banks is falling apart — especially the human habitat and households. Suburbia will only lose value and utility. Big cities will have to get smaller (ouch!).
Kunstler's solution is to go "Back to the Future."
Tradition in human societies is the great moderator of entropy.
I shouldn't be surprised, as I've pointed out his reverence for tradition before.
Kunstler has a strong streak of what Pournelle termed "irrationality" and it's what is propelling many of his views, especially those I pointed out as being conservative. His argument against marriage equality is explicitly an "irrational" one in the sense I described above. He fears that upsetting the established social contract will cause more problems than it solves, which overwhelms his desire for social justice.

Kunstler's skepticism of progress also underlies his goldbuggery and anti-immigrant positions. In fact, what his skepticism of rationality and progress animates even his liberal positions on the environment. He's much more of an anarchist than he is a liberal in that regard.
I'm not like Kunstler in that regard.  I have more of what Pournelle would consider a rational perspective, which not only makes me a liberal instead of an anarchist, but also makes me, paradoxically enough, the Crazy Eddie that I am.

Speaking of being a Crazy Eddie, I'm heartened that Bettencourt points out the limits of his analogy.
This, too, is an analogy though, because the math of cities is very different from that of stars, he says.

Cities are also massive social networks, made not so much of people but more precisely of their contacts and interactions. These social interactions happen, in turn, inside other networks – social, spatial, and infrastructural – which together allow people, things, and information to meet across urban space.

Ultimately, cities achieve something very special as they grow. They balance the creation of larger and denser social webs that encourage people to learn, specialize, and depend on each other in new and deeper ways, with an increase in the extent and quality of infrastructure. Remarkably they do this in such a way that the level of effort each person must make to interact within these growing networks does not need to grow.

How these networks fit together, and the tensions and tradeoffs among them, often determines how productive or prosperous a city is, or whether it fissions into smaller 'burbs, or if people want to live in them or don't, Bettencourt says.

His framework has practical implications for planners and policy makers, he says. To keep these social reactors working optimally, planners need to think in terms of urban policies that create positive social interactions at low costs in terms of mobility and energy use, for example. The paper shows how obstacles to socialization, such as crime or segregation, and enablers that promote the ability of people to connect, such as transportation and electricity, all become part of the same equation.
The Discovery News video lists the things that can be done to make cities more sustainable, including improving public transportation and descreasing inequality.  I'm in favor of both of these things, along with many others.  Here's to hoping that politicians and planners listen to Bettencourt's suggestions and are able to help make cities more humane as generators of human connections, and more effective at generating the desirable outputs from the system while descreasing the undesirable ones.


  1. Did somebody steal this idea of mine from the Orlov comments section a year back? If so, let me clarify: the non-industrial city must feed off the surrounding countryside, it's energy is lower and it is possible for a slow "red sun" type death. The industrial city isn't running on sunlight, it's food as well as all it's commotion, (or as you put it: social interactions) is from a much higher but limited outside energy force. And it is more realistic to say the city encompasses the whole of the USA, and the countryside is extremely marginal, because of agribusiness has replaced agriculture. Therefor when our cities/system collapses, like every other has in history, it COULD go supernova, in the way of a high energy star.

    1. Not me--I don't read Orlov regularly. However, I do read both Greer and Kunstler, and many of the same people also read Orlov, so the same ideas show up in the comments of the blogs I read and later in the entries themselves (Greer takes a lot of inspiration from his readers). That written, thanks for the comment and for sharing your perspective.