Steven Johnson began his long zoom survey with the 'prior art' of Joyce's Stephen Daedalus locating himself in himself, his neighborhood, Dublin, on out to the universe. The value of a long zoom is in identifying and employing every scale between the very large and very small, noticing how they change each other when held in the mind at the same time.

Johnson's core story (and current book) concerned London in 1854, when it was the largest city in the world and in history with 2.5 million people. London famously stank. Cess pools filled basements, slaughter houses were anywhere, garbage piled up.

Medicine at the time held that disease was caused by 'miasma,' foul air, noxious vapors. 'All smell is disease,' declared a Doctor Chadwick. The authorities decided that the way to cure the frequent cholera epidemics in London was to get rid of the bad odor - pump the sewage into the Thames, which people drank. The cholera got worse.

Johnson's goal with his book, THE GHOST MAP, was to figure out why the wrong theory of disease lingered so long, and what it took to correct it. The answer, he proposes, is in the perspective of the long zoom.