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Cityscape Cityscape (paul (dex)/flickr/CC-BY-2.0)

In this hour of Radiolab, we take to the street to ask what makes cities tick.

There's no scientific metric for measuring a city's personality. But step out on the sidewalk, and you can see and feel it. Two physicists explain one tidy mathematical formula that they believe holds the key to what drives a city. Yet math can't explain most of the human-scale details that make urban life unique. So we head out in search of what the numbers miss, and meet a reluctant city dweller, a man who's walked 700 feet below Manhattan, and a once-thriving community that's slipping away.


CORRECTION: An earlier version of this program indicated that the Dow Jones Industrial Average originated in the 1920’s.  In fact, it originated in the 1890’s; during the 1920’s it was expanded to include 30 companies, the number it includes today.  The audio has been adjusted in consideration of this fact.

In the first segment of this episode, we listed a German census as one of West and Bettencourt’s sources. This was incorrect, a German census did not appear in their data set, and the audio has been updated to reflect this correction. 

In the second segment, we used the term “watts” incorrectly. The audio has been updated to recognize this error. 


Luis Bettencourt, Diane Galusha, Dr. Robert Levine, Joan Quigley, Sxip Shirey, Nik Sokol and Geoffrey West

Produced by:

Aaron Scott

It's Alive?

There's no scientific metric for measuring a city's personality. But hit the streets, and you can see and feel it.

Comments [24]

The Belly of the Beast

Cities, like bodies, grow and evolve. In the case of New York City, that growth never would have occurred if not for a Homeric engineering feat that occurred mostly underground. Jad digs into the history of the city's water tunnels with Diane Galusha and Nik Sokol. And Sandhogs Ritchie Fitzsimmons ...

Comments [7]

Dying Embers

An underground fire sweeps through a town, and changes everything.

Comments [19]

Comments [83]

Jay from Tribe in New Zealand

"Hunter/Gatherer tribe in New Zealand"


What is background research

Jun. 13 2016 12:37 AM
Jessie Henshaw from Uptown

It's great to hear you finally trying to grapple with whether cities are more or less efficient ways to live, whether we can call them "greener" in some sense. I've been occasionally writing you about the definitive ways to ask that question for some time... ;-) There are so many poetic ways of asking it, like talking about the raw "intensity" of experience the city creates... it's "vibration", "excitement", it's pervasive "hum" sometimes possible to hear from a great distance away.

You still need a way to measure something concretely, though, to make definitive comparisons, and also to anchor any other way of looking at it. It's very clear cities produce extremely intense concentrations of work and energy consumption, and that as Jane Jacobs pointed out it has to do with the creativity of cities in putting together complex organizations of differentiated parts. But it that potential for especially intense energy use also saving energy somehow???

What a physicist does to answer it is measure the city's "energy intensity", adding up the the total energy it consumes, and stating it as a ratio either "per person" or "per $GDP" its economic energy intensity, as its efficiency in creating money. It's those ratios of energy/$GDP and energy/person are the units of measure that correspond to "greener" or "browner" in social value terms.

Generally what you find is that more money you make the more energy you use, of course, but as with your other comparisons, its used with much more efficiency (otherwise you wouldn't be being productive and getting paid more). The tricky part though, is that also means being more efficient generally goes along with earning more money(as an average of the variations), and using more not less total energy too, pretty inescapably.

Not to go on with the math, but to get to the "big issue", of why that relation has not turned up in many of the equations of city energy use, and creating a puzzling confusion. What's easy to count for a city is what's in its books, things like the money spent in the city and exchanged in trade with others outside the city... However it usually never occurs to people they need to do the same thing when counting the energy consumed. They need to count both the energy consumed inside the city,... AND... the energy consumed in delivering and receiving products in trade with others.

There's a shocker in the answer. None of the calculations for economic energy intensity being done around the world today are done that way, by "adding up the energy used inside and outside the boundary of the town" in delivering its GDP income. The reason is the keepers of city records don't think of the city as a "cell" with a "boundary", but as "the data" in the city's "log books"!! If you think about that difference a little, it has just amazing implications!

fyi -

Apr. 18 2016 09:26 PM
Cheryl Signs from Denver CO

The west is full of Ghost Towns that died because the economic base failed, usually because of changes in demand. Historically, the base was usually gold and silver but coal is now threatening.

Apr. 16 2016 04:51 PM
trisha from Athens Ohio

Who was the guy from Athens Ohio?

Apr. 16 2016 01:27 PM
Nick from Berlin

40 Min Robert.

"you can go hang yourself" !?

I know it's a joke,
but it's a pretty brutal choice of words.

THink about this.

Apr. 16 2016 11:36 AM
ivy from vancouver

cities are so attractive because of the opportunities and cultures. but i have always thought that cities are just too colourful, sometimes too quick and messy and even though we get to see tons of people everyday, we don't truly know and understand any of them.

Jan. 21 2016 11:53 PM

Death of cities. It's just a matter of time...

"Every culture that has depended on annual plants for their staple food crops has collapsed." Mark Shepard on Restoration Agriculture

Sep. 07 2014 08:51 PM
Melodie Gross from Buffalo, WY

As I was listening to this very interesting piece,an add for TEVO was aired right after the segment about cities being greener as they increased in size. Preceding this segment was the number of patents relating to population size. My mind wandered to the idea that TEVO could claim promote a green lifestyle because people can skip ads, therefore reducing their amount of time spent using electricity to power their TV. Another benefit would be not promoting commercialism because people would not view the commercials which influence them to purchase unnecessary items. their also a correlation between TEVO/Cable TV and the level of a person's 'green' behaviors?

Sep. 07 2014 03:54 PM
Robert Thomas from Santa Clara

An initial attempt to post was rejected, probably because of my long-windedness.

So I'll be more brief.

This was an interesting and thought provoking edition. Though I hadn't heard it before, I guess this was the third or fourth presentation, since 2010.

The facts about physical quantities mentioned - energy, power and so forth and the unit 'Watt' were (as some other commenters have noted) mishandled.

In fact, mishandling of this type plagues Radiolab so profusely that it not only obscures occasionally but calls into question the veracity of EVERY FACT PRESENTED.

It strongly suggests that, though no one would doubt the sincere desire of Radiolab’s writers, producers or Mr Krulwich’s or Mr Abumrad’s personal passion for Radiolab’s mission - which I believe is the meaningful interpretation of scientific and philosophical researches for the benefit of a thoughtful lay audience - that no one involved with the production has a sufficient grasp of the basic knowledge or language of science to recognize when such horrendous errors occur. Guests appearing on Radiolab understand these things, surely. But that’s not the same thing.

Those able to recognize such errors are merely startled. And the technical error may be inconsequential and not critical to the communication of a concept. But sometimes it *is* critical. Then, the lay person takes away error. They take away erroneous understanding.


What is to be done?

Sep. 06 2014 07:55 PM
Jana Everett from Denver KCFR

In the "Cities" show in the segment on the factors that correlate with walking speed, the argument was that size of city is associated with walking speed. But I have read other research that contends that cities in rich countries have faster walking speeds than cities in poor countries. Nothing was mentioned about GDP in the segment, and I think that was an oversight.

Sep. 06 2014 04:54 PM
Staycox from Dallas, Texas

I grew up in Southern California and moved to Whitehorse Canada, a very small town in the Yukon territory. I was only there for 6 months, but what I noticed right off the bat was how fast the people walked. Conversely, years later, I visited the Virgin Islands and was amazed at how people seemed like they moved in slow motion. Both places were low population, non-cities. My non-scientific theory is that it may be based on climate.

Sep. 04 2014 09:12 AM
Benjamin Fraser

Radiolab is amazing in general and this episode is one of my favorites (though it's hard to choose). If you are interested in cities, I invite you to listen to a new podcast I'm launching on Urban Cultural Studies (not nearly as well produced or researched, but I hope to learn along the way). The first one focuses on Spain:

001 UCS Stephen Vilaseca on Street Art in Barcelona, Valencia and Bilbao Spain (21'44")

Conversational interview inspired by scholar Stephen Vilaseca's recent article "From Graffiti to Street Art: How Urban Artists Are Democratizing Spanish City Centers and Streets," originally published in the journal Transitions: Journal of Franco-Iberian Studies (8, 2012). Topics include: public space, graffiti vs. street art, artists Escif, Frágil and Dr. Case, Valencia, Bilbao, and Barcelona. See more related content at .

This and future podcasts can be accessed here:

Jun. 28 2013 01:12 PM
Nathan from Osaka

City people in Japan don't walk quickly at all. It's weird to see people walking so slowly in such a hyper-urban place.

Jun. 28 2013 11:54 AM

I also am from New zealand, and must disagree with new zealand being a hunter-gatherers tribal country. This is a very beautiful country, and yes, people like growing their own fruit and vegetables, but the majority of people, go to a normal day to day supermarket. We've got everything that the rest of the world has too. While NZ may be small, we are still a first world country.

Apr. 07 2013 06:47 PM
natlou from Detroit

I live in Detroit, and despite what the locals say... it's pretty much dead. The buildings are there and there's a little business... but it is not considered a real city. People who will argue this have probably not experienced a real city. They also have a small town mentality. Go downtown any day of the week, no matter what time or the weather and it's pretty much ghostly. A friend from France visited here and he told me how he spent hours trying to photograph people in the morning, and no one was around. People can argue all they want... but currently, there's nothing here.

Mar. 18 2013 04:38 PM
John Lazzeroni

In the podcast about cities, the guy said that you need 11,000 watts per capita per day in a city but requiring a watt per day would mean that you are changing the rate at which you use electricity. He should have said that you need about 11,000 joules of electricity per day. You need energy per day, you don't need energy per second per day. Just a technical error but this is a common misconception in everyday life.

Mar. 10 2013 12:55 PM
Janan from Pleasant Hill, CA

What an interesting program about cities. I found all of your shows fascinating, just when I think, oh this one is really good, no way can this show be topped, but you continue to amaze and surprise. The comment about each city makes its own time, my family and I moved to the US many years ago from the Middle East, one thing that we all noticed as a family was that time went by so quickly in the new land, and being only 12 at the time, I could not comprehend how can time be different from one place to another. But as the years quickly flew by, and each time I visited a new place, I paid close attention to time there. The more slowly one moved, the more slowly time seemed to pass, the more events took place in a day, the more quickly that day seemed to pass. Yet, if one moved as fast as the speed of light, then time would stop still, to me that is the biggest puzzle of all, I would think that time would go by more quickly not stop still, in the end, time is a relative thing. It depeneds on a person's perspective and awareness, and now I supped you can even add the city to that equation.

Feb. 25 2013 02:37 PM

Visitors and new residents to big Cities fairly soon are walking, driving and talking as fast as the prevailing flow--out of social necessity--and the constant pressure to conform. People move faster in the biggest cities, partly because acute congestion/competition makes it a daily necessity.

Nov. 24 2012 09:10 PM
Jessie Henshaw from Way Uptown

The much more curious fact than that growth produces systems that *SEEM* to use less energy per cell is that growth also invariably multiplies energy use at the same time in total.

Another still more curious fact is that the reason it seems that way is that larger systems consume more energy per unit of ecosystem services from ***outside the system***. That's what's behind the vast mismeasure of our impacts, why people living high in NYC seem to have, statistically, far below average per person consumption of the world's resources...!! QED

Nov. 24 2012 06:40 PM
Jessie Henshaw from Way Uptown

What a pile of Bull you feed us today!! There are lots of quite interesting **correlations**, but no correlation is a cause of anything but speculation by idle theorists. To find cause an effect you need to study the processes by which things are made.

Talk to me I'll tell you lots more about just how to turn over the stones and see what's living underneath! ;-)

Nov. 24 2012 06:18 PM
Laura from Boca Raton, FL

Amazing program !

Nov. 24 2012 12:48 PM
Steve Pierce from Munroe Falls, Ohio

Super show--especially loved the bit on Centralia. You all bring the radio to life. Thank you.

Nov. 23 2012 08:57 PM
shaw from portland, oregon

totally awesome

Oct. 14 2012 02:44 PM
LenEll from St. Louis

Roger Levine did his initial study of walkers in big cities in 1994. Richard Wiseman, from the University of Hertfordshire in England, did a follow up study in 2006 that showed that overall the average city walking speed was increasing. New York, the only American city on the list, stayed the same between the two. Here is a link to the list:

May. 03 2012 11:13 PM

Oh! Another city that's about to die:

Apr. 16 2012 10:54 AM

I'm curious about the walking speed experiment. Living in Chicago, it can get bitterly cold here in the winter. My friends and I were walking much faster than normal because it was so cold. Colder cities would have to have a faster pace then, right? And what about time of day. People walk faster in the morning when they're trying to get to work on time. As opposed to a nice day on a weekend, where people might stroll at a more leisurely pace.

Mar. 19 2012 12:44 AM

@Bernard from melbourne. I'm pretty sure the city in the picture is of Toronto taken from the CN Tower. Unless Nathan Phillips Square, The Royal York and Union Station have been abducted and are being held hostage buy Melbourne.

Feb. 12 2012 02:53 PM

@Bernard from melbourne. I'm pretty sure the city in the picture is of Toronto taken from the CN Tower. Unless Nathan Phillips Square, The Royal York and Union Station have been abducted and are being held hostage buy Melbourne.

Feb. 12 2012 02:50 PM

Is there any way to find recordings of that Spanish Pentecostal Church music?
The one he said was clearly the best music he'd ever heard.
It sounded incredible!

Nov. 07 2011 09:07 PM
Bernard from melbourne

I had thought of an experiment you could do to quantify the "speed" of cities. Pull up at random street lights in your car then don’t move when they go green. Someone starts a stopwatch the moment the light goes green and you time how long it is before the person behind honks their horn. Where I live now (Melbourne - it’s the city shown in the picture to illustrate the episode) it would probably average a couple of nano seconds. Where I grew up in Tasmania prob 10 seconds

Nov. 02 2011 01:17 AM

What about people walking in the sands of Ipanema in Rio de Janeiro?

Oct. 22 2011 09:00 PM
Jeddah from Las Vegas

The song that plays on 12:06 is IRON & WINE - Sixteen Maybe Less

Aug. 23 2011 11:36 AM

@ Jordan from Westfield, click on Sxip Shirey's name. It's a hyper link that takes you to his website.

Jul. 07 2011 03:29 PM
Jordan from Westfield, NJ

Where is the music by Sxip Shirley?
I'd love to hear it, and Jad says in the episode that it is available on the website....

Jun. 07 2011 02:29 PM
bob minder

can't begin to express how much i've been enjoying radiolab. a new discovery enriching my life. am sure you get these sort of comments all the time, but here goes: couldn't help thinking as i was enjoying cities how cool it would have been to have used west berlin during the airlift to help define a city. seems as if you had one open as if in surgery for inner exploration of the systems needed to make life as well as how a personality changes after major surgery and recovery!!! bob minder

Mar. 12 2011 05:31 AM
cristina from melbourne

A friend of mine was born in Yallowrn, Victoria (Australia). It was a mining town and it doesn't exist any more. It's not unusual in Australia.

Mar. 11 2011 08:20 AM
John from St. Louis, MO

Enjoyed this episode. Made me think of a comicbook superhero who is the "King of Cities"

Feb. 04 2011 11:07 AM
harron from suburban Chicago

In the words of the "car guys," the size,walking speed etc. correlation sounds bo-o-o-o-gus! Whether measurements take place on crowded walks or on side streets, winter or tourist summer all must vary. So, too, raw population isn't a measure of how prosperous a city it is. Prosperity can boom with changes in economy. A "third world" city of 5 mil isn't the same as one in, say Europe. These factors and others must have impacts on stats. Finally, I can't be the first to point this out. You should have mentioned the Public TV show on NYC, its water and sand hogs as well. Thanks!

Jan. 22 2011 04:55 PM
Shlee from Philadelphia, PA

Hey Guys, Nice work on "Cities." I concur with some commentors- I wanted to know the name of the two physicians and to learn more about their research!!! Blah!

Otherwise, read below- I like the physics discussion. Especially the critiques about measurements, i.e.- Watts.

Cheers Radiolab!

Jan. 20 2011 01:31 PM
BradyDale from Philadelphia

Guys, I love the podcast and the show! But I'm a little grumpy right now. I came here to try to find the names of those writers who did the cool research on cities, and it's just not jumping out at me here. That seems like a natural for your write-ups. Include the names and credentials of your guests - prominently!

Dec. 10 2010 09:34 AM
Rick Baum from Wanganui, New Zealand

I was listening to your podcast on Cities recently when you made a rather egregious comment regarding how much power a person uses. Your examples included a person in a coma and someone in a hunter-gatherer tribe in New Zealand. As an ex-pat who lived in New York, among other places, I am appalled at this assumption with regard to a country you have never seen first-hand. New Zealand, for your information, is a first world country. Maori people, the tribal people you refer to generally have middle-class lives and live in houses with phones, internet connections and televisions. Most of their hunting is done at the local grocery store which looks surprisingly like the Stop and Shop. It is such a New York thing to assume that anyone who does not live in Manhattan is some sort of primitive living in a cave. Maybe if you left your little island you would discover that the rest of us are civilized as well.

Dec. 07 2010 04:18 PM
Brendan from Seattle

I love this episode. The bit where you talk about each city having its own 'beat' or 'song' really kind of fascinates me. It's like an audio version of a city's culture. There are some mysterious psychological effects associated with just being inside of the city. It's like being subconsciously brainwashed by the social pressures around you.

I'd be curious to know whether the psychological effects of feeling like an outsider in a city have an effect on your walking speed, among other things. Like, whether or not you adopt them on the fly when you travel to a different city just by being exposed to the environment, or if it's something far less interesting. For instance, tourists walk about this speed, people walking to work walk this speed, etc. and we're all just apart of some giant statistic.


Dec. 07 2010 06:52 AM
Eilis Crean

Eilis in Atlanta, remembering footfall in Dublin, Ireland.
Cities: Has the frequency, unpredictability, duration and temperature of rain showers and buses been considered in the data - definitely impetus to increase walking pace in Baile Atha Cliath! Great program.

Dec. 06 2010 07:34 PM

I agree with John H from NY (11/4): The description of the "Watts" as what's used is misleading. Watts is a measure of a *rate* of energy use/transfer. Watts is to velocity as energy is to position or distance traveled; it tells you how quickly you're using energy, not how much you used. You could have said that resting people use energy at the same rate as a 90-W light bulb. But over a specific time interval, like a day, that's energy - kilowatt-hours (kWh, what you pay for in your electricity bill; using energy at a rate of 1000 W for an hour means you used one kWh). kWh are the same beast as BTUs and Joules, too - it's all energy. Love the show, but as a researcher on conceptual difficulties in physics, I notice things like that. Overall, you guys do a great job explaining things at a layperson level while keeping the essence of the science intact.

Dec. 04 2010 12:13 PM

Like several other posters on 'Fate and Fortune,' I too didn't get this ('Cities') episode on podcast; I have 'Oops,' then2 shorts, 'Words,' then a rebroadcast of 'Time.' What's up, and with all due respect, why haven't you answered this repeatedly-asked question yet??

Nov. 26 2010 07:49 PM
Mike from Brooklyn

Would it be possible to post a transcript of this episode?

Nov. 22 2010 03:25 PM
Simone from New Zealand

The stories of the people living on a burning coal mine rung a few little cords with me. I am from Christchurch, New Zealand. After the quake when airlines offered cheap flights and people were fleeing the city to get away from the aftershocks - I became stubbornly loyal, refused to leave, privately believing people that did leave were making a much bigger deal of it than it was - betraying our city that needed us. Even though I like to think I can think objectively about basic survival, I did feel myself loving my city even more. Must of been that primal instinct! Hopefully if it meant imminent death I would leave...

Nov. 21 2010 06:03 PM

I'm not sure why someone isn't trying to at least use some of that enormous amount of heat that's being generated and turn it in to electricity! Surely that's possible.... It's like a 400 acre boiler for a steam turbine!

Nov. 12 2010 02:14 PM

With regards to the difference between urban area and greater metro area: Geoff West and Louis Bettencourt's work (along with most people who study these kinds of things) is all based on metro area population. There's actually some semi-standard way of determining that number. I think Boston ends up around 3 million or so.


Nov. 12 2010 12:54 PM
Asbjørn Jon Andersen from Denmark

Great show, i would love to hear more about the cities. In your show someone (can´t remember who) said that cities never dies, it wolud be interesting to hear something about cities that actually are dying eg. Detroit or other cities that been left and become more or less ghostcities.

At CPH:DOX a man called Florent Tillon made a film Detroit Wild City it has some very interesting views. Well im just thinking about myself and how nice it would be with a show with that topic :D

Nov. 12 2010 02:40 AM
Ryan Kudasik

I found the Centrailia piece so interesting. I went to grad school in nearby Bloomsburg. We named our fictious company for a project Centrailia inc.

Thanks for the piece. I thought it was so interesting to hear from the people.

Nov. 10 2010 05:28 PM
Brian from Sonora, CA

I'm not an urban geographer, but I have an obvious observation regarding the correlation between city size and myriad factors: there is sometimes a big population difference when you look at city proper and urban and/or metropolitan area. Boston proper is quite small (600,000), even though most people would think it feels much larger. And, as in the case with Boston, the surrounding areas (e.g. Cambridge) are not your average suburbs. The same goes for San Francisco. On the other end of the spectrum, cities like New York and LA are similarly big whether you look at their proper, urban or metropolitan numbers.

Nov. 10 2010 11:45 AM

Guys, great show as usual. However, I think you created a false dichotomy between "city" and "country" in the discussion about consumerism, suggesting that consumption of resources invariably increases as one moves from country to city.

I think there is more to it, beginning with a discussion of suburbs. I believe the data affirm that suburban environments lead to greater resource consumption per person than urban environments -- due to factors such as lower population density, more reliance on cars versus mass transit, etc.

Also, I would argue that the phenomenon of consumerism, i.e. buying more things as a means of self-fulfillment, is more associated with the suburbs and less with true urban environments, where interpersonal interaction, cultural diversity, and other sources of satisfaction are more readily available.

Historically, I would peg the spike in mass consumerism not with the growth of modern cities in the mid to late 1800s, but with the growth of the suburbs in the years following World War II.

Nov. 09 2010 05:17 PM
Lauren from Lexington, KY

As usual, I thoroughly enjoyed the show. It was interesting to me to combine the physicists thinking about walking speed and the variables of a city according to size with the information of a psychologist.

On some level, I wish you had done Detroit instead of Centralia. It sounded like Centralia was a tiny town--and there are ghost towns scattered all over the West. Towns do die. Your point was that cities do not. There are vibrancies to Detroit, and yet at the same time 40% of it is vacant. It is possible to farm land while staring at skyscrapers. It is an odd and slightly post-apocalyptic experience.

Did you see this essay of the late-Tony Judt in the New York Times today? Beautiful description of the city and a nice correlation to listening to you all.

Nov. 08 2010 04:21 PM
Laura Cramer

Wonderful piece on Centralia. My mother's family is from nearby Mt. Carmel, and it's always been really fascinating to me.

Nov. 08 2010 01:50 PM
Jose from Queens

This was a great episode.
If you are interested in the NYC watershed system--which BTW provides way better water than all those bottles we buy daily--the Queens Museum of Art has an exhibit dedicated to it. It includes a scale model of all of the reservoirs and the various tunnels.
More info here:

Nov. 07 2010 04:44 PM
drummerman from Brooklyn

What I actually find most on target is the "non" scientific parts of this episode. The stroll through BK really said more than all the stats and such combined. The human cost of the high tech "progress" used to build cities (water tunnels, ie) and promote this idea that it is all inevitable - hearing the workers themselves actually defend the system that KILLED and maimed them. The deception of the community of Centralia by the corporate mine rulers, the divide and conquer of the town.
The simple question behind it all, "hey, is this even a good idea? Isn't there an enormous cost to all of this?"
I feel like this show said (and I mean this as a compliment!), in a "white guy" way some of the things that indigenous communities have been trying to say for generations. But in this "language" city folks and well, white guys, can actually understand the profound errors in our society.

Nov. 07 2010 11:15 AM
newbiedoo from California

I've been reading the comments on this episode, and have to agree with many posters that there are several other aspects to the subject that could be fleshed out. May I suggest a follow-up Cities?
That said, what a great episode! I've been obsessing on personality/pace of places ever since!

Nov. 07 2010 08:39 AM
Jack Bauer is dead

Great episode! Love the piece about Centralia. That place is creepy some.

Nov. 05 2010 02:52 AM
Dillon from Tulsa, OK

I really love this show! this episode was great but I just listened to it while riding my bike through downtown Tulsa and I kept thinking that cars were coming up from behind me. However, one of my favorite things is the clever editing of the shows. Keep it up guys!

Nov. 04 2010 05:45 PM
Brian Orlick

That is an average of 2000 Calories (kilocalories) over 24 hours. Check it out with the Google calculator:

Nov. 04 2010 05:17 PM
John H from NY

At ~38:00
"If you lie in your bed all day you will consume about 90W of electricity."

This doesn't make sense, Watts is a measure of the rate of power consumption, that's like saying it takes my car consumes 30mpg to get to the mall. Did you mean laying in your bed your heat output is a constant 90W? Is this assuming your bed is in a room that is using no power for heating/cooling/lighting? If so of course you use way more when you consider the ability to drive, go to the movies etc. because your comparison to laying in bed only includes power generated internal to your body. I love the show but I think this was a very misleading and confusing comparison.

Nov. 04 2010 11:25 AM

I heart cities... I'm "city" sick, as in "home" sick
...and your new website, especially the brain as parachute - great

Nov. 04 2010 05:39 AM
Malwina from New York, NY

On November 9th, Robert Krulwich will be taking part in a conversation about Cities with editor Lewis Lapham, historian Andrew Dolkart, architect Jeffrey Inaba, and Columbia University dean Mark Wigley. Learn more about the event or register here:

Nov. 03 2010 03:03 PM
nichole from CT, USA

Guys, love the podcast. But what is with the GLaDOS voice? Creepy!

"Good news, I figured out what that thing you just incinerated did. It was a morality core they installed after I flooded the enrichment center with a deadly neurotoxin to make me stop flooding the enrichment center with a deadly neurotoxin, so get comfortable while I warm up the neurotoxin emitters."

Nov. 02 2010 11:55 AM
Andrew from San Diego

What a great episode on an interesting topic. I would, however, like to point out that, contrary to the suggestion of the last segment, the decline or collapse of cities isn't as rare as the guest would suggest. Every single archaeological site is an abandoned town. Cities are capable of existing for quite a few generations, but the trend seems to indicate that abandonment is more of the norm than the exception when viewed in a wider perspective.

Oct. 27 2010 03:53 PM

What song is played during the break starting at ~40:30?

Oct. 26 2010 08:21 PM

I tried the recommendations (subscribing and unsubscribing, feeding your url into iTunes), and I'm still not seeing the last two podcasts in iTunes. I look forward to listening to these at the gym, it's a highlight of my week; please fix whatever issues there are!

Oct. 22 2010 04:24 AM
Gobo from cro

I really don't like the new page design not because it looks like some stupid Monty Python joke but because I don't get around it. Podcasts used to be displayed chronologically but now it's like circus. I have no idea how to list them chronologically. And worst of all I downloaded one podcast only to discover it was only first 20 minutes and not the whole thing.
Really why did you need to change it?

Oct. 21 2010 04:00 PM
Sean in Dublin from Dublin, Ireland

Hey thoward,

Thanks for taking the time to reply and I will certainly check out Levine's work when I get a chance. Much appreciated.

But, as much as I love Radiolab and audience participation, it does seem a little confusing to be calling out non-scientific samples that contradict the main premise of the segment, right at the same time that Jad and the Physicists are moving on to declare that these numbers hold the key to certain universal truths about cities around the world.

Nonetheless, my feelings of unease are perhaps born more of my suspicion of the very premises of the research itself than of your show. In particular I would have suspected that politico-cultural (and in that sense infrastructural and economic) factors must surely enter into these methodologies to make their results at all serviceable or useful.

If, as you say, the Physicists admit that cultural factors of some sort must be taken into account, then precisely that interaction between the mathematical data and societal difference would seem to me to be the much more interesting and important variable to discuss in the show rather than simply emphasising the universal aspects of these abstract averages.

We can surely all agree that cities are human collectives. But the first approach would seem to me to have enlightened us about the interaction between our collective endeavours over time and the material world that envelopes us. While the second (put foward in the show) emphasises a rather unfortunate and fatalistic conception of mechanical "cause and effect" development, beyond the control of human input - much like bees in a hive.

Again... love the show... just my two cent on this particular piece.


Oct. 21 2010 12:43 PM

Hi Sean,
Good questions - this points to something we should have made clearer in the piece. For our little non-scientific demonstration of Robert Levine's walking speed studies, we only stated the average speed for fastest and slowest, Dublin and Buchanan, Liberia; the other walking speeds are just individual samples, not city averages (and yes, I believe Oslo and Copenhagen came out about equally fast). I recommend checking out Levine's book, A Geography of Time, for his much more thorough pace of life studies' results and correlations.

Another interesting thing to consider is that according to West and Bettencourt (the physicists), each country has a different baseline for its variables (e.g. crime, economy, patents) because of cultural differences...but once you account for that, the exact same scaling laws do hold as you move up in size within that country.

Oct. 20 2010 12:46 PM
Ale from San Francisco

Here is another nuance to this topic:

Author: Steve Johnson
Title: Where Good Ideas Come From

"The more species Kleiber and his peers analyzed, the clearer the equation
became: metabolism scales to mass to the negative quarter power. The math is simple enough: you take the square root of 1,000, which is (approximately) 31, and then take the square root of 31, which is (again, approximately) 5.5. This means that a cow, which is roughly a thousand times heavier than a woodchuck, will, on average, live 5.5 times longer, and have a heart rate that is 5.5 times slower than the woodchuck's. As the science writer George Johnson once observed, one lovely consequence of Kleiber's law is that the number of heartbeats per lifetime tends to be stable from species to species.
Bigger animals just take longer to use up their quota. ...

"Several years ago, the theoretical physicist Geoffrey West decided to investigate whether Kleiber's law applied to one of life's largest creations: the superorganisms of human-built cities. Did the 'metabolism' of urban life slow down as cities grew in size? Was there an underlying pattern to the growth and pace of life of metropolitan systems?

"But the most fascinating discovery in West's research came from the data that didn't turn out to obey Kleiber's law. West and his team discovered another power law lurking in their immense database of urban statistics. Every datapoint that involved creativity and innovation - patents, R&D budgets, 'supercreative' professions, inventors - also followed a quarter-power law, in a way that was every bit as predictable as Kleiber's law. But there was one fundamental difference: the quarter-power law governing innovation was
positive, not negative. A city that was ten times larger than its neighbor wasn't ten times more innovative; it was seventeen times more innovative. A metropolis fifty times bigger than a town was 130 times more innovative.

Oct. 20 2010 12:10 PM
A Brakob

Why is this episode not on the podcast rss feed?

Oct. 20 2010 10:29 AM
Kim from Long Island

For anyone interested in the social story of the cleared out burning coal city, there's an episode about it on This American Life. You'll have to look back into the archives though. A lot of people were determined not to go

Oct. 20 2010 10:18 AM
RB180 from NYC

Why isn't this episode appearing in iTunes?

Oct. 19 2010 06:55 PM


Solar arrays and wind farms would be one better use.

I think the best use, however, would be for humans to leave the land alone and let nature take over again.

Oct. 19 2010 03:42 PM
Sean in Dublin from Dublin, Ireland

I really dont get the city "walking beat" segment. The two physicists make these massive reductionist claims about how the common determinant is size (and that all other geographic feautures are superficial). But then even the very small number of actually declared step-speed results completely contradicts that.

For example if Dublin city centre has a high step-speed with 10.7 (with 1m pop and roughly .5 million urban pop) then why would a denser city like Manhattan be slightly slower while a comparatively similar city such as Copenhagen (with 1 million urban pop) is almost twice as slow at 21.5!!

And why would another North European city, Oslo, with almost the exact same urban population as Copenhagen size (roughly 1m urban) turn out to be in between the two at 14.4?

And lets not even get into the difference between two densest conurbations in the list: Mexico city being 10.1 secs while Mumbai measures 27 secs!

So how does "average footfall" help anyone work out even the most obvious things about a city?

Oct. 19 2010 04:47 AM

What is a better use for land than growing food?

Oct. 18 2010 01:42 PM
Ben Eby from Denver, CO

This was a great episode. I wish you would have included a segment about Vertical Farms though. Vertical Farms would have been a perfect fit for this episode's theme.

If you guys don't know much about Vertical Farms, you can read more about them here:

The concept is basically to grow food inside of skyscrapers rather than spread over vast areas of land that could be put to a better use.

I think this idea has great merits and more people should know about it. I would love for you guys to do a show about it. Please consider it.

Oct. 18 2010 12:28 PM
nik from NYC

Mia...interesting! I'll turn this into a controversy...the story I have always heard is that the town cleaned up for their big bicentennial (?) celebration, used a sinkhole as a dump pit and then burned the garbage and then so on as you describe.

Oct. 18 2010 10:40 AM
Meatbag Pussrocket

@Wout theories often present themselves very differently depending on application. the cities application is revealing in meaningful ways.

Oct. 14 2010 10:35 PM
Mia from Ford City, PA / Philadelphia, PA

I went to Centralia, PA twice - on two different college field trips.

I remember being told that the anthracite coal mines underground caught on fire on a Memorial Day decades ago when a family's grill fell through the ground via a sink hole and caught the coal veins on fire.

At first the city didn't have enough money to put it out and so, they didn't. As it burned and the fire grew the city /really/ didn't have any money to do anything and it still burns to this day.

Oct. 11 2010 04:17 PM

Hey is it just me or are they asking questions they already know the awnsers to.

they start off by asking about how do city's come to being and all that stuff while they already said how in the show emergence

Oct. 09 2010 08:49 AM

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