Students and teachers: Take a good look at the world map on your classroom wall. If Alaska looks as big as Brazil (it's actually less than a fifth its size), you're probably looking at some variation on the Mercator projection - the most influential world map in the last 400 years.
Designed to aid European navigators, the Mercator map (1569) enlarges areas at the poles to create straight lines of constant bearing, or geographic direction. It makes it easier to cross an ocean, but distorts the relative size of nations and continents.
But this view of the world is facing competition in the classroom and elsewhere from newcomers that present dramatically different views of the world.
An Australian map puts south at the top, illustrating the principle that maps are more political than they seem at first glance. Since the earth is round, any flat map will have distortions.
"There's no escape from the cartographic paradox: to present a useful and truthful picture, an accurate map must tell white lies," writes geographer Mark Monmonier in his book "How to Lie with Maps" (The University of Chicago Press, 1996).
One of the most explicitly influential maps with a political agenda is the Peters projection, which claims to be "cartographically superior" to the Mercator map and to "reduce ethnic bias." Developed by German historian Arno Peters in 1967, this version represents Africa and South America as considerably larger than they appear on traditional maps.
"Maps both picture our existing vision of the world - distortions and all - and they create it. The value of the Peters projection is that it seeks to portray all areas of the world, and therefore all peoples, in equal space," says Ward Kaiser, former executive director of Friendship Press, which published the first North American edition of the Peters projection.
While still little known in the United States, the Peters world map is popular with missionaries and international aid organizations, and is now used extensively in the British school system. Some groups use the map for diversity training in education and the workplace.
"We use the map as a metaphor for thinking outside the box and learning to question one's assumptions," says Bob Abramms, senior associate of ODT Inc., a management consulting agency based in Amherst, Mass., which now markets the Peters map.
"When people see the contrast [with other world maps], their jaws drop. And they start to wonder: 'If I held this to be inviolate about my ideas of the world, how many other biases do I have that I have not discovered?' "
Professional cartographers, including those at National Geographic, note that the Peters map introduces powerful inaccuracies of its own, especially distortion of the shape of continents.
Peters supporters agree that their map has serious shape distortions, but argue that that does not make it any less useful. "No map is good for all purposes," responds Mr. Kaiser. "One always needs to ask: What are the trade-offs? What distortions am I willing to accept? And the basic question: What is the purpose for which I wish to use this particular map?"
(c) Copyright 1999. The Christian Science Publishing Society