The Ghost Map: The Story of London's Most Terrifying Epidemic--and How It Changed Science, Cities, and the Modern World

by Steven Johnson

without any central planner coordinating their actions, without any education at all, this itinerant underclass managed to conjure up an entire system for processing and sorting the waste generated by two million people.

“The removal of the refuse of a large town,” he wrote, “is, perhaps, one of the most important of social operations.” And the scavengers of Victorian London weren’t just getting rid of that refuse—they were recycling it.

but without efficient forms of waste recycling, those dense concentrations of life can’t survive for long.

“Whilst pestilence slays its thousands, fear slays its tens of thousands.”

Brewed tea possesses several crucial antibacterial properties that help ward off waterborne diseases: the tannic acid released in the steeping process kills off those bacteria that haven’t already perished during the boiling of the water. The explosion of tea drinking in the late 1700s was, from the bacteria’s point of view, a microbial holocaust.

But it was the wrong time for such a discovery: the germ theory of disease had not yet entered mainstream scientific thought,

went on to revolutionize the use of statistics in public health in the following decade.

belief in the power of statistics to shed light on medical riddles.

Many genetically minded historians believe that the confluence of urban living and the discovery of alcohol created a massive selection pressure on the genes of all humans who abandoned the hunter-gatherer lifestyle.

To digest large quantities of it, you need to be able to boost production of enzymes called alcohol dehydrogenases,

Many early agrarians lacked that trait, and thus were genetically incapable of...

The descendants of hunter-gatherers—like many Native Americans or Australian Aborigines—were never forced through this genetic bottleneck, and so today they show disproportionate rates of alcoholism.

their alcohol intolerance mostly likely has another explanation: their ancestors didn’t live in towns.

Chadwick helped solidify, if not outright invent, an ensemble of categories that we now take for granted: that the state should directly engage in protecting the health and well-being of its citizens, particularly the poorest among them; that a centralized bureaucracy of experts can solve societal problems that free markets either exacerbate or ignore; that public-health issues often require massive state investment in infrastructure or prevention. For better or worse, Chadwick’s career can be seen as the very point of origin for the whole concept of “big government” as we know it today.

Whenever smart people cling to an outlandishly incorrect idea despite substantial evidence to the contrary, something interesting is at work.

To reconcile this hideous reality with the idea of a beneficent Creator, Whitehead had settled on what might later have been termed an ingeniously Darwinian explanation: that plagues were God’s way of adapting the human body to global changes in the atmosphere, killing off thousands or millions, but in the process creating generations that could thrive in the new environment.

his cholera theory would ultimately depend on his skills as a sociologist.

This is how great intellectual breakthroughs usually happen in practice. It is rarely the isolated genius having a eureka moment alone in the lab. Nor is it merely a question of building on precedent, of standing on the shoulders of giants, in Newton’s famous phrase. Great breakthroughs are closer to what happens in a flood plain: a dozen separate tributaries converge, and the rising waters lift the genius high enough that he or she can see around the conceptual obstructions of the age.

What united them all as a group was that they were old and infirm and living alone, with the result that they didn’t have anyone to fetch water for them.

And it was precisely their metropolitan connection that made this solution possible: two strangers of different backgrounds, joined by circumstance and proximity, sharing valuable information and expertise in the public space of the great city.

Broad Street case was certainly a triumph of epidemiology, and scientific reasoning, and information design. But it was also a triumph of urbanism.

The bird’s-eye view remains as essential as it was back in 1854. When the next great epidemic does come, maps will be as crucial as vaccines in our fight against the disease.

The model involves two key principles, both of which are central to the way cities generate and transmit good ideas. First; the importance of amateurs and unofficial “local experts.”

second principle is the lateral, cross-disciplinary flow of ideas.

Death and Life of the Great American City.

Yet that doesn’t mean continued urbanization is inevitable. It just means that the potential threats will come from somewhere else. Most likely, if some new force derails our mass migration to the cities, it will take the form of a threat that specifically exploits density to harm us, just as Vibrio cholerae did two hundred years ago.

Some experts think a pandemic on the order of 1918 is a near inevitability.

Any DNA-based agent can effectively be neutralized after its release, by any number of different mechanisms: early detection and mapping, quarantine, rapid vaccination, antiviral drugs.

It’s entirely likely, of course, that we will see the release of an infectious agent engineered in a rogue lab somewhere, and it’s at least conceivable that the attack could unleash a pandemic that could kill thousands or millions—particularly if such an attack took place in the next decade or so, before our defensive tools have matured.

thanks to urban density and global jet travel, it’s probably easier now for a rogue virus to spread around the globe,

However profound the threats are that confront us today, they are solvable, if we acknowledge the underlying problem, if we listen to science and not superstition, if we keep a channel open for dissenting voices that might actually have real answers. The global challenges that we face are not necessarily an apocalyptic crisis of capitalism or mankind’s hubris finally clashing with the balanced spirit of Gaia. We have confronted equally appalling crises before. The only question is whether we can steer around these crises without killing ten million people, or more.