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Marchetti’s Constant: The curious principle that shapes our cities
How the half-hour commute and motorised transport changed our cities into huge metropolises.

From small to sprawl: how a curious constant (and modern transport technology) determine city sizes.
- The average commute, from antiquity to now: half an hour
- That's Marchetti's Constant, and it informs the growth of our modern cities
- But we're stuck in traffic, and waiting for the next great leap forward.
The curious constant
Charles T. Harvey, president of the West Side & Yonkers Patented R.R., New York City's first elevated railway, demonstrating in 1867 that a car would not fall off the track.
Image source: public domain
What do the citizens of ancient Rome have in common with those of modern Atlanta? The duration of their daily commute: an hour, at most. No matter whether we move on foot or by car, half an hour either way is about as long as we're prepared to travel to and from our place of work.
That timeless truism is called Marchetti's Constant, and it has a curious effect on the size of our cities. For as our modes of transport improve, the result is not that our commutes shrink, but that the distance between our homes and places of work increases. That, Jonathan English explains in a fascinating article over at CityLab, is why ancient Rome was tiny, and modern Atlanta is huge.
When in Rome
Even when it was the biggest city in the world, Rome was tiny by modern standards.
Image source: David Rumsey Map Collection courtesy Stanford University Libraries, CC-BY-NC-SA; image credit: David Montgomery/CityLab
For most of history, walking was the main way to get around cities. Since a mile (1.6 km) is about as far as you can walk in half an hour, that's the maximum radius of a pre-modern city. Actually, ancient Rome is a good example: for several centuries at the start of the Common Era, it was the world's biggest city. Yet its one million inhabitants were packed like Latin-speaking sardines into an area with a diameter of just two miles.
That's about the same distance as from the Bastille to the Louvre, the extremities of medieval Paris. And, as Jonathan English remarks in his article, "the historic City of London is named the 'Square Mile' for a reason." Up until the Industrial Revolution, urban growth meant cities got denser rather than bigger, leading to horrific levels of overcrowding. Escape to the country was a luxury available exclusively to the very rich — only they could afford both a rural mansion and an urban pied à terre.
The advent of modern transport brought the ideal of an escape from the city within reach of ever greater numbers of city-dwellers — but the effect was ultimately self-defeating: the growing size of the urban exodus meant they brought the city with them. But that change didn't happen overnight: our current cityscapes are the result of centuries of experiments with transportation modes — always with Marchetti's Constant as a yardstick for growth.
Philosopher on the bus
Medieval Paris was a bit smaller than Rome, a thousand years earlier.
Image source: Analyse Diachronique de l'espace Urbain Parisien: Approche Geomatique, Open Data Commons Open Database License 1.0; image credit : David Montgomery/CityLab
- The first public transit system was introduced in Paris in 1662 by none other than Blaise Pascal, the philosopher. His system of horse-drawn buses followed a set schedule, along fixed routes, for a distance-based fare. However, the system wasn't much faster than walking, and collapsed after 15 years due to increased ticket prices.
- In 1830, Liverpool and Manchester were connected by the world's first steam-powered public railway. Railways caught on quickly in major cities across the world. Moving people at speeds of 10 miles or more per half hour, railways allowed those who could afford it to live in "railroad suburbs" along the stops outside the city proper. Examples include Philadelphia's Main Line suburbs and West London's Stockbroker Belt.
- From the 1880s, the introduction of electric trams and "safety bicycles" (i.e. not the high-wheeled penny-farthings) extended the commuter range of more lowly-paid workers. They now could travel in half an hour to 4 miles. This enlarged the potential size of cities from a diameter of 2 miles (i.e. 3 square miles) to a diameter of 8 miles (i.e. 50 square miles). Over the next decades, cities all over North America, and to a lesser extent Europe, adopted tram networks, and started sprouting new suburbs.
- Elevated trains, suspended above their straight streets avenues, further spurred the growth of American cities. These "el trains" and later subways, allowed the working class to live as far as 8 miles from their places of work. This allowed New York to spread out north to cover the entirety of Manhattan, for example.
Going Underground
London was one of the first cities to transcend the ancient limits of urban development.
Image source: David Rumsey Historical Map Collection, CC BY-NC-SA; image credit: David Montgomery/CityLab
- Lacking an American-style grid, London's streets were not amenable to elevated trains. Because they couldn't go up, they went under, and in 1863, the first London Underground line opened. The 'Tube' would soon become instrumental for spreading out the city over the surrounding counties, eventually annexing large parts of them. The county of Middlesex was almost entirely absorbed by Greater London (see #605), and disappeared off the map.
- In 1908, Henry Ford launched the Model T, the first mass-produced car. Despite its eager adoption by the middle classes, the automobile did not create huge urban growth in the 1920s and 1930s. That's because the roads, built for non-motorized traffic, quickly choked up. Only after WWII would cars would start to transform cities — thanks to the introduction of expressways, which allowed people to move to and from cities with greater speed.
- After WWII, urban planners developed two competing methods to finally overcome the problem of inner-city overcrowding. The mainly European method, developed by Le Corbusier, was to concentrate people in free-standing high-rise towers, set in parkland ringing the old city centers.
Welcome to Chicagoland
The sprawl of 'Chicagoland' was made possible by the street car.
Image source: Harvard Map Collection, Harvard College Library; image credit: David Montgomery/CityLab
- The predominantly American method, developed by Frank Lloyd Wright, was based on the car, and proposed dispersing the population over a much wider area, on individual plots of land — a recipe for what has become the classic American suburb. This model allows for a 20-mile commute in 30 minutes, and that extends the metropolitan diameter to 40 miles. An "expressway city" can thus cover more than 1,250 square miles.
- In the 1970s, Wright's model proved so successful that North America's inner cities emptied out; except for its African-American inhabitants, kept out of the suburbs by various means of institutional discrimination. These days, the standard commute in North American metro areas takes around 26 minutes — about the same as that of the average citizen of ancient Rome.
- In the last few decades, the dispersal model has become the victim of its own success: traffic has multiplied, slowed down and become congested. Los Angeles, Atlanta, and other "expressway cities" have hit maximum capacity.
Sprawl ad infinitum?
The dispersal model, the latest (and perhaps ultimate) phase of urban expansion.
Image source: U.S. Census; image credit: David Montgomery / CityLab
So, what's next after 'stuck in traffic'? Jonathan English suggests three technological solutions, with varying degrees of feasibility:
- First option: high-speed rail. Downsides: very expensive, and facing "formidable ideological opposition" — at least in North America.
- Second option: self-driving cars. Downsides: still a pipe dream, will not improve road capacity, and may even increase congestion.
- Third option, and the most viable one: telecommuting. Working from home is already technologically feasible and holds "the greatest promise" for enabling Wright's vision of the complete dispersal of population. But employers are resistant: they want their staff on-site, their physical presence the ultimate guarantee for productivity.
Images reproduced with kind permission of David Montgomery at CityLab. Read the entire article here on CityLab.
Strange Maps #988
Got a strange map? Let me know at strangemaps@gmail.com.
How New York's largest hospital system is predicting COVID-19 spikes
Northwell Health is using insights from website traffic to forecast COVID-19 hospitalizations two weeks in the future.
- The machine-learning algorithm works by analyzing the online behavior of visitors to the Northwell Health website and comparing that data to future COVID-19 hospitalizations.
- The tool, which uses anonymized data, has so far predicted hospitalizations with an accuracy rate of 80 percent.
- Machine-learning tools are helping health-care professionals worldwide better constrain and treat COVID-19.
The value of forecasting
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTA0Njk2OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyMzM2NDQzOH0.rid9regiDaKczCCKBsu7wrHkNQ64Vz_XcOEZIzAhzgM/img.jpg?width=980" id="2bb93" class="rm-shortcode" data-rm-shortcode-id="31345afbdf2bd408fd3e9f31520c445a" data-rm-shortcode-name="rebelmouse-image" data-width="1546" data-height="1056" />Northwell emergency departments use the dashboard to monitor in real time.
Credit: Northwell Health
<p>One unique benefit of forecasting COVID-19 hospitalizations is that it allows health systems to better prepare, manage and allocate resources. For example, if the tool forecasted a surge in COVID-19 hospitalizations in two weeks, Northwell Health could begin:</p><ul><li>Making space for an influx of patients</li><li>Moving personal protective equipment to where it's most needed</li><li>Strategically allocating staff during the predicted surge</li><li>Increasing the number of tests offered to asymptomatic patients</li></ul><p>The health-care field is increasingly using machine learning. It's already helping doctors develop <a href="https://care.diabetesjournals.org/content/early/2020/06/09/dc19-1870" target="_blank">personalized care plans for diabetes patients</a>, improving cancer screening techniques, and enabling mental health professionals to better predict which patients are at <a href="https://healthitanalytics.com/news/ehr-data-fuels-accurate-predictive-analytics-for-suicide-risk" target="_blank" rel="noopener noreferrer">elevated risk of suicide</a>, to name a few applications.</p><p>Health systems around the world have already begun exploring how <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7315944/" target="_blank" rel="noopener noreferrer">machine learning can help battle the pandemic</a>, including better COVID-19 screening, diagnosis, contact tracing, and drug and vaccine development.</p><p>Cruzen said these kinds of tools represent a shift in how health systems can tackle a wide variety of problems.</p><p>"Health care has always used the past to predict the future, but not in this mathematical way," Cruzen said. "I think [Northwell Health's new predictive tool] really is a great first example of how we should be attacking a lot of things as we go forward."</p>Making machine-learning tools openly accessible
<p>Northwell Health has made its predictive tool <a href="https://github.com/northwell-health/covid-web-data-predictor" target="_blank">available for free</a> to any health system that wishes to utilize it.</p><p>"COVID is everybody's problem, and I think developing tools that can be used to help others is sort of why people go into health care," Dr. Cruzen said. "It was really consistent with our mission."</p><p>Open collaboration is something the world's governments and health systems should be striving for during the pandemic, said Michael Dowling, Northwell Health's president and CEO.</p><p>"Whenever you develop anything and somebody else gets it, they improve it and they continue to make it better," Dowling said. "As a country, we lack data. I believe very, very strongly that we should have been and should be now working with other countries, including China, including the European Union, including England and others to figure out how to develop a health surveillance system so you can anticipate way in advance when these things are going to occur."</p><p>In all, Northwell Health has treated more than 112,000 COVID patients. During the pandemic, Dowling said he's seen an outpouring of goodwill, collaboration, and sacrifice from the community and the tens of thousands of staff who work across Northwell.</p><p>"COVID has changed our perspective on everything—and not just those of us in health care, because it has disrupted everybody's life," Dowling said. "It has demonstrated the value of community, how we help one another."</p>3,000-pound Triceratops skull unearthed in South Dakota
"You dream about these kinds of moments when you're a kid," said lead paleontologist David Schmidt.
Excavation of a triceratops skull in South Dakota.
- The triceratops skull was first discovered in 2019, but was excavated over the summer of 2020.
- It was discovered in the South Dakota Badlands, an area where the Triceratops roamed some 66 million years ago.
- Studying dinosaurs helps scientists better understand the evolution of all life on Earth.
Credit: David Schmidt / Westminster College
<p style="margin-left: 20px;">"We had to be really careful," Schmidt told St. Louis Public Radio. "We couldn't disturb anything at all, because at that point, it was under law enforcement investigation. They were telling us, 'Don't even make footprints,' and I was thinking, 'How are we supposed to do that?'"</p><p>Another difficulty was the mammoth size of the skull: about 7 feet long and more than 3,000 pounds. (For context, the largest triceratops skull ever unearthed was about <a href="https://www.tandfonline.com/doi/abs/10.1080/02724634.2010.483632" target="_blank">8.2 feet long</a>.) The skull of Schmidt's dinosaur was likely a <em>Triceratops prorsus, </em>one of two species of triceratops that roamed what's now North America about 66 million years ago.</p>Credit: David Schmidt / Westminster College
<p>The triceratops was an herbivore, but it was also a favorite meal of the T<em>yrannosaurus rex</em>. That probably explains why the Dakotas contain many scattered triceratops bone fragments, and, less commonly, complete bones and skulls. In summer 2019, for example, a separate team on a dig in North Dakota made <a href="https://www.nytimes.com/2019/07/26/science/triceratops-skull-65-million-years-old.html" target="_blank">headlines</a> after unearthing a complete triceratops skull that measured five feet in length.</p><p>Michael Kjelland, a biology professor who participated in that excavation, said digging up the dinosaur was like completing a "multi-piece, 3-D jigsaw puzzle" that required "engineering that rivaled SpaceX," he jokingly told the <a href="https://www.nytimes.com/2019/07/26/science/triceratops-skull-65-million-years-old.html" target="_blank">New York Times</a>.</p>Morrison Formation in Colorado
James St. John via Flickr
Triceratops illustration
Credit: Nobu Tamura/Wikimedia Commons |
Put on a happy face? “Deep acting” associated with improved work life
New research suggests you can't fake your emotional state to improve your work life — you have to feel it.
What is deep acting?
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTQ1NDk2OS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNTY5MzA0Nn0._s7aP25Es1CInq51pbzGrUj3GtOIRWBHZxCBFnbyXY8/img.jpg?width=1245&coordinates=333%2C-1%2C333%2C-1&height=700" id="ddf09" class="rm-shortcode" data-rm-shortcode-id="9dc42c4d6a8e372ad7b72907b46ecd3f" data-rm-shortcode-name="rebelmouse-image" data-width="1245" data-height="700" />Arlie Russell Hochschild (pictured) laid out the concept of emotional labor in her 1983 book, "The Managed Heart."
Credit: Wikimedia Commons
<p>Deep and surface acting are the principal components of emotional labor, a buzz phrase you have likely seen flitting about the Twittersphere. Today, "<a href="https://www.bbc.co.uk/bbcthree/article/5ea9f140-f722-4214-bb57-8b84f9418a7e" target="_blank">emotional labor</a>" has been adopted by groups as diverse as family counselors, academic feminists, and corporate CEOs, and each has redefined it with a patented spin. But while the phrase has splintered into a smorgasbord of pop-psychological arguments, its initial usage was more specific.</p><p>First coined by sociologist Arlie Russell Hochschild in her 1983 book, "<a href="https://www.ucpress.edu/book/9780520272941/the-managed-heart" target="_blank">The Managed Heart</a>," emotional labor describes the work we do to regulate our emotions on the job. Hochschild's go-to example is the flight attendant, who is tasked with being "nicer than natural" to enhance the customer experience. While at work, flight attendants are expected to smile and be exceedingly helpful even if they are wrestling with personal issues, the passengers are rude, and that one kid just upchucked down the center aisle. Hochschild's counterpart to the flight attendant is the bill collector, who must instead be "nastier than natural."</p><p>Such personas may serve an organization's mission or commercial interests, but if they cause emotional dissonance, they can potentially lead to high emotional costs for the employee—bringing us back to deep and surface acting.</p><p>Deep acting is the process by which people modify their emotions to match their expected role. Deep actors still encounter the negative emotions, but they devise ways to <a href="http://www.selfinjury.bctr.cornell.edu/perch/resources/what-is-emotion-regulationsinfo-brief.pdf" target="_blank">regulate those emotions</a> and return to the desired state. Flight attendants may modify their internal state by talking through harsh emotions (say, with a coworker), focusing on life's benefits (next stop Paris!), physically expressing their desired emotion (smiling and deep breaths), or recontextualizing an inauspicious situation (not the kid's fault he got sick).</p><p>Conversely, surface acting occurs when employees display ersatz emotions to match those expected by their role. These actors are the waiters who smile despite being crushed by the stress of a dinner rush. They are the CEOs who wear a confident swagger despite feelings of inauthenticity. And they are the bouncers who must maintain a steely edge despite humming show tunes in their heart of hearts.</p><p>As we'll see in the research, surface acting can degrade our mental well-being. This deterioration can be especially true of people who must contend with negative emotions or situations inside while displaying an elated mood outside. Hochschild argues such emotional labor can lead to exhaustion and self-estrangement—that is, surface actors erect a bulwark against anger, fear, and stress, but that disconnect estranges them from the emotions that allow them to connect with others and live fulfilling lives.</p>Don't fake it till you make it
<p>Most studies on emotional labor have focused on customer service for the obvious reason that such jobs prescribe emotional states—service with a smile or, if you're in the bouncing business, a scowl. But <a href="https://eller.arizona.edu/people/allison-s-gabriel" target="_blank">Allison Gabriel</a>, associate professor of management and organizations at the University of Arizona's Eller College of Management, wanted to explore how employees used emotional labor strategies in their intra-office interactions and which strategies proved most beneficial.</p><p>"What we wanted to know is whether people choose to engage in emotion regulation when interacting with their co-workers, why they choose to regulate their emotions if there is no formal rule requiring them to do so, and what benefits, if any, they get out of this effort," Gabriel said in <a href="https://www.sciencedaily.com/releases/2020/01/200117162703.htm" target="_blank">a press release</a>.</p><p>Across three studies, she and her colleagues surveyed more than 2,500 full-time employees on their emotional regulation with coworkers. The survey asked participants to agree or disagree with statements such as "I try to experience the emotions that I show to my coworkers" or "I fake a good mood when interacting with my coworkers." Other statements gauged the outcomes of such strategies—for example, "I feel emotionally drained at work." Participants were drawn from industries as varied as education, engineering, and financial services.</p><p>The results, <a href="https://psycnet.apa.org/doiLanding?doi=10.1037%2Fapl0000473" target="_blank" rel="noopener noreferrer">published in the Journal of Applied Psychology</a>, revealed four different emotional strategies. "Deep actors" engaged in high levels of deep acting; "low actors" leaned more heavily on surface acting. Meanwhile, "non-actors" engaged in negligible amounts of emotional labor, while "regulators" switched between both. The survey also revealed two drivers for such strategies: prosocial and impression management motives. The former aimed to cultivate positive relationships, the latter to present a positive front.</p><p>The researchers found deep actors were driven by prosocial motives and enjoyed advantages from their strategy of choice. These actors reported lower levels of fatigue, fewer feelings of inauthenticity, improved coworker trust, and advanced progress toward career goals. </p><p>As Gabriel told <a href="https://www.psypost.org/2021/01/new-psychology-research-suggests-deep-acting-can-reduce-fatigue-and-improve-your-work-life-59081" target="_blank" rel="noopener noreferrer">PsyPost in an interview</a>: "So, it's a win-win-win in terms of feeling good, performing well, and having positive coworker interactions."</p><p>Non-actors did not report the emotional exhaustion of their low-actor peers, but they also didn't enjoy the social gains of the deep actors. Finally, the regulators showed that the flip-flopping between surface and deep acting drained emotional reserves and strained office relationships.</p><p>"I think the 'fake it until you make it' idea suggests a survival tactic at work," Gabriel noted. "Maybe plastering on a smile to simply get out of an interaction is easier in the short run, but long term, it will undermine efforts to improve your health and the relationships you have at work. </p><p>"It all boils down to, 'Let's be nice to each other.' Not only will people feel better, but people's performance and social relationships can also improve."</p>You'll be glad ya' decided to smile
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="88a0a6a8d1c1abfcf7b1aca8e71247c6"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/QOSgpq9EGSw?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>But as with any research that relies on self-reported data, there are confounders here to untangle. Even during anonymous studies, participants may select socially acceptable answers over honest ones. They may further interpret their goal progress and coworker interactions more favorably than is accurate. And certain work conditions may not produce the same effects, such as toxic work environments or those that require employees to project negative emotions.</p><p>There also remains the question of the causal mechanism. If surface acting—or switching between surface and deep acting—is more mentally taxing than genuinely feeling an emotion, then what physiological process causes this fatigue? <a href="https://www.frontiersin.org/articles/10.3389/fnhum.2019.00151/full" target="_blank">One study published in the <em>Frontiers in Human Neuroscience</em></a><em> </em>measured hemoglobin density in participants' brains using an fNIRS while they expressed emotions facially. The researchers found no significant difference in energy consumed in the prefrontal cortex by those asked to deep act or surface act (though, this study too is limited by a lack of real-life task).<br></p><p>With that said, Gabriel's studies reinforce much of the current research on emotional labor. <a href="https://journals.sagepub.com/doi/abs/10.1177/2041386611417746" target="_blank">A 2011 meta-analysis</a> found that "discordant emotional labor states" (read: surface acting) were associated with harmful effects on well-being and performance. The analysis found no such consequences for deep acting. <a href="https://doi.apa.org/doiLanding?doi=10.1037%2Fa0022876" target="_blank" rel="noopener noreferrer">Another meta-analysis</a> found an association between surface acting and impaired well-being, job attitudes, and performance outcomes. Conversely, deep acting was associated with improved emotional performance.</p><p>So, although there's still much to learn on the emotional labor front, it seems Van Dyke's advice to a Leigh was half correct. We should put on a happy face, but it will <a href="https://bigthink.com/design-for-good/everything-you-should-know-about-happiness-in-one-infographic" target="_self">only help if we can feel it</a>.</p>World's oldest work of art found in a hidden Indonesian valley
Archaeologists discover a cave painting of a wild pig that is now the world's oldest dated work of representational art.
Pig painting at Leang Tedongnge in Indonesia, made at 45,500 years ago.
- Archaeologists find a cave painting of a wild pig that is at least 45,500 years old.
- The painting is the earliest known work of representational art.
- The discovery was made in a remote valley on the Indonesian island of Sulawesi.
Oldest Cave Art Found in Sulawesi
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="a9734e306f0914bfdcbe79a1e317a7f0"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/b-wAYtBxn7E?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>What can Avicenna teach us about the mind-body problem?
The Persian polymath and philosopher of the Islamic Golden Age teaches us about self-awareness.
