Projections

No, this is not another post about why the Tea Party is always yakking about things like Death Panels.

This may not be front page news, but to those of us who like maps, it’s pretty interesting. (I’d use the word “exciting,” but frankly no one is going to believe that people interested in maps get excited.)

The classic work on map projections–John P. Snyder’s Map Projections: A Working Manual (1987)–has been put up on the Web by the United States Geological Survey. Snyder was the kind of person that is rapidly vanishing in this country, someone who is deeply interested in a subject, enough to become an expert, with not the slightest interest in how it can make him wealthy. A professional chemist, he was an amateur cartographer who attended professional conferences on his own time. He was only able to begin serious work on his own, when programmable calculators became affordable in the 1970s. (Yes, my friends, there was a day when we old fogies were required to use a pencil and paper to do calculations or estimate the result with a slide rule. I believe you can see examples of pencil, paper and slide rules at the Smithsonian.) In 1976 he developed the space-oblique Mercator projection, a cylindrical projection that tracked a satellite orbit for use in connection with satellite photographs of the earth. He gave his work to the United States Geological Survey free of charge, proving he would not be fit to live in our more enlightened times, which have been designed for high-end earners. He was offered a job by the USGS and while there produced the work on projections.

The book narrates the history and describes the mathematics of all major projections used by cartographers of earth. The USGA has made the entire 385 page book available in DjVu format (for which you can get a free plug at Caminova) as well as online in pdf format. I must say, however, that neither my old ThinkPad nor my relatively new Macbook seemed able to access more than the first page of the online version, which displayed “loading” for much longer than my attention span allowed. Downloading the DjVu plug-in and the text is a much more satisfying way to go.

Incidentally, I will note here a set of unrelated observations about GPS navigation by Véronique Bohbot, a psychiatrist at McGill University, and colleagues, made at the annual meeting of the Society for Neuroscience in San Diego last month. (The page I just cited notes that Glenn Close spoke at the meeting to explain how science and “society” can work together. It also explained where to make lost-and-found inquiries.) Dr. Bohbot, according to a summary by Discovery News, explained how persons using GPS for navigation showed less activity in the hippocampus (measured by functional magnetic resonance imaging) than those who navigated by “spatial navigational strategy.” Because the hippocampus is associated with memory, they associated preference for GPS navigation with impairment of memory–an assumption they claim was borne out by cognitive testing. They only noted the correlation; the don’t for example speculate whether GPS usage “causes” memory impairment or that the memory-impaired select the GPS method. Nevertheless, several popular publications have distorted the remarks. An article in the Hartford Courant, for example, was entitled “Is GPS Making Us Stupid?” If you have ever read the Hartford Courant, you will most likely have answered with the rest of its readers that no, there are other reasons the writers of the Courant are stupid. All of that said, I think it’s safe to conclude, even without Dr Bohbot’s work, that map usage is a superior form of information retrieval to either one she studied.

Update [same day]: Despite what I said above, eventually the pdf file of Snyder’s book will load and you can then save it to your disk. But at 16.8 MB it is nearly three times larger than the DjVu document.

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