Solving the problem of the city, scientifically
by Sarah Goodyear.
Anyone
who thinks that cities are key to the future of a sustainable human presence on
the planet—and anyone who thinks the contrary—should read Jonah Lehrer’s fascinating
piece in yesterday’s New York Times Magazine, “A Physicist Solves the City.”
In it,
Lehrer examines the ideas of Geoffrey
West, a theoretical physicist who (with his colleague Luis Bettencourt) has come up with a variety of
mathematical equations that attempt to define and explore the essential nature
of cities. (West’s and Bettencourt’s work was also featured on a recent excellent episode of Radiolab that I
discussed in an earlier
post.)
As
Lehrer writes, “West considers urban theory to be a field without
principles, comparing it to physics before Kepler pioneered the laws of
planetary motion in the 17th century.”
And
so he set out to discover those laws—proceeding on the assumption that they
exist, and can be mined and refined from the chaos of urban life.
West
first noticed the similarities between cities and living organisms:
This
implied that the real purpose of cities, and the reason cities keep on growing,
is their ability to create massive economies of scale, just as big animals do.
After analyzing the first sets of city data – the physicists began with
infrastructure and consumption statistics – they concluded that cities looked a
lot like elephants. In city after city, the indicators of urban “metabolism,”
like the number of gas stations or the total surface area of roads, showed that
when a city doubles in size, it requires an increase in resources of only 85
percent.
But
West and his colleagues then realized was that the true essence of a successful
city can’t be explained by efficiency:
[A]
city is not just a frugal elephant; biological equations can’t entirely explain
the growth of urban areas…. “In retrospect, I was quite stupid,” West says. He was
so excited by the parallels between cities and living things that he “didn’t
pay enough attention to the ways in which urban areas and organisms are
completely different.”
What
Bettencourt and West failed to appreciate, at least at first, was that the
value of modern cities has little to do with energy efficiency. As West puts
it, “Nobody moves to New York to save money on their gas bill.” Why, then, do
we put up with the indignities of the city? Why do we accept the failing
schools and overpriced apartments, the bedbugs and the traffic?
In
essence, they arrive at the sensible conclusion that cities are valuable
because they facilitate human interactions, as people crammed into a few square
miles exchange ideas and start collaborations. “If you ask people why they move
to the city, they always give the same reasons,” West says. “They’ve come to
get a job or follow their friends or to be at the center of a scene. That’s why
we pay the high rent. Cities are all about the people, not the infrastructure.”
The
agglomeration of all those people leads to a lot of innovative thinking—which
is good, because we need the innovations to keep pace with our ever-growing
appetites. (See some recent related discussions of David Owen’s New
Yorker article on energy efficiency
and the Jevons paradox).
Lehrer
writes this about West’s evolving thinking on the city and its role as a hotbed
of innovation:
There is a serious complication to this triumphant narrative
of cliff edges and creativity, however. Because our lifestyle has become so
expensive to maintain, every new resource now becomes exhausted at a faster
rate. This means that the cycle of innovations has to constantly accelerate,
with each breakthrough providing a shorter reprieve. The end result is that
cities aren’t just increasing the pace of life; they are also increasing the
pace at which life changes. “It’s like being on a treadmill that keeps on
getting faster,” West says. “We used to get a big revolution every few thousand
years. And then it took us a century to go from the steam engine to the
internal-combustion engine. Now we’re down to about 15 years between big
innovations. What this means is that, for the first time ever, people are
living through multiple revolutions. And this all comes from cities. Once we
started to urbanize, we put ourselves on this treadmill. We traded away
stability for growth. And growth requires change.”
Ultimately, West’s research affirms his belief in the
organic resilience of megalopolises. But is he right? Is this real
science? Can cities continue to grow without collapsing in on themselves?
With more than 50 percent of the world’s populations now living in urban areas, much depends on the answer.
Related Links:
Helmet Wars: A gripping account of the great bicycle helmet campaigns
Memo to ecovores: It’s cheaper being green
Who will own the smarter cities of the future?
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