Friday, December 08, 2006

The Ghost Map, by Steven Johnson

Read a great book by Steven Johnson on the map created by John Snow in wake of the cholera epidemic in London in 1854. I first read about the map (from an information representation point of view) in one of Edward Tufte's books, of course, but here we get a detailed picture of the epidemic itself, social conditions of the time, London as a young metropolis, the state of science, and even a little primer on microbiology. In the first part of the book, Johnson tells the tale of the epidemic chronologically, with many side paths into the above-mentioned topics. Though the side paths are fascinating, sometimes they just slow the narrative down - you're saying, "wow, that's a neat metaphor about how the 'river of intellectual progress is not defined purely by the steady flow of good ideas begetting better ones; it follows the topography that has been carved out for it by external factors,' but, c'mon, I want to know who gets the cholera next!!"

Apart from the gripping story of the cholera epidemic, there are a couple of themes that I thought Johnson discussed particularly well. The first I mentioned above - Johnson explores how scientific ideas are shaped by ideological context. It's not a revolutionary idea, but the book has a particularly graphic and rich example in terms how diseases and the possibility of microbes were conceived of in mid-19th century Europe.

The second fascinating theme Johnson touches on in the end, with a discussion of how London, with is population of 2 million in the 1850's, was an experiment in whether that many people could actually live packed so densely together. It was a time when rudimentary water and sewer services were just being planned and built, and Johnson is particularly graphic is describing how the garbage and sewage of the city's inhabitants were handled. The experiment succeeded of course and we have megacities now, some of whose slum areas are repeating the developments that London went through 150 years ago. In any case, it's an interesting study of the history of cities on our planet.

I highly recommend this quick but informative read - you'll not only ponder the nature of scientific inquiry and the development of cities, but also learn what pure-finders search for and how cholera strips the epitheleal cells from the small intestine thus leading to a "rice water" stools. Priceless!