The Long Zoom

I’ve gotten completely hooked on listening to the Long Now seminars on my way to work. The other day, it was Steven Johnson talking about The Long Zoom - his riff on the name.

People are used to talking about “putting things in context” as if there were only one. His basic point is that everything happens in multiple contexts - physical, social, and chronological - and within nested layers scope for each. No one of them is the “right” one, a single overriding way of framing the situation. If you want to really understand the causes and effects, you need to know what’s going on in all of them. You need to build a composite view of what’s happening at different levels of detail, and understand how they interact.

He applies this in his book The Ghost Map. There, he’s looking at the London cholera epidemic of 1854, which sounds like it would just be plain unpleasant, but turns out to be fascinating, and significant in a number of ways.

Part of it is about a bunch of people dying, and what cholera bacteria do to you; the progress of the disease through an individual. But from there he zooms out to how it travels through the neighborhood; to the story of the guys pounding the pavement, trying to follow its course and figure out how to stop it.

The layer on top of that is the government and citizens of London, trying to create the infrastructure they need to support the largest urban population to that point in history. Their efforts at waste management and recycling were the latest in the evolution of practices and technologies that went back hundreds of years.

They were also part of a global effort to deal with an ever-growing population. It was widely believed that London would eventually collapse under its own weight, and people would go back to living in little country villages. Thomas Malthus had already published his treatise on population, and convinced a lot of people that it was only a matter of time before the whole human race imploded, as food consumption outstripped production.

If these problems hadn’t been solved, if London had been unable to grow beyond that point, the world would be different. Much of what we take for granted in modern life, for good or ill, comes from the emergent behavior of large cities.

There’s also a related stack of issues around the evolution of medical science. Solving the problem of cholera was not just a matter of figuring out a few things about biology. To have any effect, that understanding had to be converted into proof that others would act on, and there began an uphill battle.

Accepted doctrine at the time held that cholera was caused by miasma - bad air. At the level of the human sensory system, in the detailed world of neurobiology, this seems obvious: London as a whole smelled awful, and the poor areas, where everyone was coming down with cholera, smelled the worst. Your nose is very sensitive, and wired straight into an alarm reflex. Your eyes aren’t so good. Even billions of cholera bacteria in a glass of water make up a mass too small to see. They don’t smell bad, and you can’t taste them.

This sensory bias led to the doctrine of miasma, which was promoted by the medical authorities of the day and widely taught. Medical authorities stay authorities by not being proven wrong, and colleges are similarly dependent on their reputations. So now this low-level bit of neurological misdirection is reinforced by the societal layers of career-minded individuals and larger and longer-lived social institutions.

What ultimately defeated cholera in this case was statistical analysis. They didn’t have microscopes strong enough to see the bacteria, but they had enough people getting sick for it to be mathematically useful. In this way, the size of London worked in its favor. They also had a city government that was sophisticated enough to be gathering statistics about mortality, and open enough to publish them. Both the focus on facts over theories and the valuing of openness over secrecy were traits that were relatively new in the life of cities.

To top it off, he also looks at all of this from the bacteria’s perspective, which is simultaneously the smallest and largest, the shortest time frame and the longest. An individual bacteria has a lifespan measured in hours and is easily defeated by a living host. But cholera as a strain has been around for millenia, and a drop of water can hold millions, more than enough to overwhelm a healthy human. From its perspective, people are just another kind of particularly hospitable terrain, and a septic system leaking into a well is like a land bridge to Asia rising out of the ocean.

These all correspond to zoom levels of time, as well. The progress of the disease is measured in hours. The investigation spanned days. Urban public works projects, months and years. The growth of cities, decades and centuries. Ditto for scientific thought, though individual discoveries play out over months or years. Cultural norms regarding disease and poverty may only change over centuries or millennia, if then. People still argue that certain illnesses are divine punishment, just as they would have in the dark ages. The aspects of human physiology in play here have been constant for millions of years.

So if you’re only looking at part of the picture, you run out of causality at some point. If you just look at the investigative level, you leave thinking that the whole problem is that people can’t see bacteria. At the infrastructure level, the problem is just wells and sewers too close together. With the scientific establishment, you just have a bunch of stuffy old academics. Or really, the only thing wrong was that the medical practitioners didn’t know that you just had to keep giving victims clean drinking water so they didn’t die of dehydration. Each of those is the truth, but not the whole truth. Each is just one slice of this wondrously, maddeningly complex, interconnected world we live in.