2001-07-27 I did not get the impression she was complaining about the use of metres, but the use of the 20 m interval. She might not have complained if the map interval was 10 m instead. Maybe, you or someone else, can write to her and ask why the maps are at 20 m intervals and not 10 m? Find out if 10 m would satisfy her. Then you will know if using metres or just the interval chosen is the issue or not. John Keiner ist hoffnungsloser versklavt als derjenige, der irrt�mlich glaubt frei zu sein. There are none more hopelessly enslaved then those who falsely believe they are free! Johann Wolfgang von Goethe (1749-1832) ----- Original Message ----- From: "Nat Hager III" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Sent: Friday, 2001-07-27 15:33 Subject: [USMA:14661] Denver Post > Now don't everyone get mad at once. Remember, it's just someone who went > into journalism, because he/she couldn't pass basic math/science. > > The important thing is just to monitor, and make sure articles like this > aren't having significant influence on public thinking. > > Nat > > ------------------------------------------- > > Copyright 2001 The Denver Post Corporation > The Denver Post > > > July 24, 2001 Tuesday 2D EDITION > > SECTION: DENVER & THE WEST; Pg. B-09 > > LENGTH: 870 words > > HEADLINE: Another mapmaking revolution > > BYLINE: By Penelope Purdy, > > BODY: > The U.S. Geological Survey, purveyor of America's definitive maps, has > spent your tax money on a new system that makes the most used detailed > terrain maps, called topos, less useful. > > Few items are more essential to a backcountry traveler than accurate > topological maps. They not only show roads and trails, they use colors and > contour lines to depict steep hillsides, deep canyons, rugged peaks and > impassable bogs. > > Even in the age of Global Positioning Systems, a topo remains uniquely > suited for specific tasks. It is the end product of centuries of human > attempts to show the world in a useful way, as much a statement about our > civilization as it is of the physical world. > > The most detailed topos used by the general public are 7.5 minute > quadrangles. In the past, the 'seven-and-half quads' showed terrain in > 40-foot intervals, so if there was a 50-foot cliff in the way, you could > avoid it. > > Now the USGS has embraced a 20-meter contour interval. The metric system > might have worked - if the bureaucrats had chosen a reasonable vertical > distance. > > But 20 meters translates into about 66 feet, a vertical distance that can > hide an annoyingly large number of cliffs and other obstacles. > > The upshot: The 21st century maps being created by the USGS are less useful > than those it produced the 1960s. > > Surely the 20-meter standard was the harebrained creation of some > flatlander who has never stumbled through the chaos of a mountain boulder > field. > > A friend and I discovered the new maps' shortcomings traipsing around > California's Sierra Nevada. The particular climbing route was fairly > straightforward. The problem was finding the (expletive) thing. We spent a > quarter of an entire day stumbling through the talus at the peak's base > because our map's 20-meter interval lead us into several 40-foot drop-offs. > > People who love electronic toys may smirk that, well, we should've just had > ourselves a GPS unit. But GPS has many shortcomings. Batteries fail, > signals die in thick forest cover or among deep cliffs, and even the new > gizmos are heavy and bulky compared to a map and compass. > > Worse, a GPS makes a person focus on the gadget rather than the world > around them. I've been stopped on the trail by GPS users who asked to see > my paper map. I even witnessed hikers stand around and argue about where > they needed to go, when the path they sought was a few yards in front of > their noses. > > Now, consider this: While returning from the California climb, my buddy and > I hiked out by a crescent moon's faint light. Given the awful time we had > finding the climbing route, we wanted to reach camp by a route different > from the one we'd taken earlier - a tricky problem for GPS, which records > only known data points. > > But because I'd been glancing at a topo all day, I had in my head a pretty > good notion of the terrain that lay to either side of our original path. > Thus, we could walk without using our headlamps. Often in the backcountry, > you don't want to use your lights because they destroy your night vision so > all you can see is that small circle of light. And staring at the > illuminated screen of a GPS causes the same problem. > > Trouble was, of course, that the mental picture I had was based on the > USGS' new 20-meter interval, so we still encountered several drop-offs - a > problem euphemistically called getting 'cliffed-out.' > > You can sympathize with the mapmakers' dilemma: They need to depict a > spherical world on a flat surface, so there's always some distortion - it's > like trying to detail a basketball on a postage stamp. But if mapmakers > pick the wrong mathematical formula, or projection, the map ends up > unsuitable for broader use. That's basically what's happened to USGS quads. > > That's also what happened to a dude named Gerardus Mercator who invented a > decent map for navigating oceans in the mid-latitudes. His projection was > part of the massive 16th century revolution in cartography, which erupted > as knowledge of the Western Hemisphere reached the emerging scientific > caste in Europe and forever changed how humans envision their world. > > Trouble was, people misused Mercator's map to form government policy, too. > And since Mercator's projection showed Europe disproportionately large and > minimized Africa and other southern locales, it skewed the world view > widely held by generations of politicians and school kids. It was a classic > case of misunderstanding the product of technology - for maps are as much > about politics as geography. > > Today, satellites and computers are fomenting another mapmaking revolution, > the likes of which civilization hasn't seen since Mercator's era. Maps are, > in a sense, the very foundation upon which our society has been built and > continues to evolve. > > But like politics, sometimes technology embraces silly notions. And the > 20-meter interval is a classic case of a technocrat's convenience > overriding the needs of the on-the-ground user. > > Penelope Purdy ([EMAIL PROTECTED]) is a member of The Denver Post > editorial board. >
