if i want to turn this globe into a flat map, i’m going to have to cut it open. in order to get this to look anything like a rectangle. i've had to cut it in places. i've had to stretch it so that the countries look all wonky. and even still, it's almost impossible to get it to lie flat.
When Is The Lying Game Coming Back, and that right there is the eternal dilemmaof map makers: the surface of a sphere cannot be represented as a plane without some formof distortion. this guy proved that with math a long timeago. since around 1500s, mathematicians have setabout creating algorithms that would translate
the globe into something flat. to do this, they use a process called projection. popular rectangular maps use a cylindricalprojections. imagine putting a theoretical cylinder overthe globe and projecting each point of the sphere onto the cylinder’s surface. unroll the cylinder, and you have a flat,rectangular map. but you could also project the globe ontoother objects, and how exactly a map maker projects the globe will affect what the maplooks like once it’s all flattened out. and here’s the big problem: every one ofthese projections comes with trade offs in
shape, distance, direction and land area. certain map projections can be either misleadingor very helpful depending on what you are using them for. here’s an example. this map is called the mercator projection. if you’re american, you probably studiedit in school. it’s the projection google maps uses. mercator projection is popular for a coupleof reasons. first, it generally preserves the shape ofthe countries.
brazil on the globe has the same shape asbrazil on the mercator projection. but the real purpose of the mercator projectionwas navigation -- it preserves direction, which is a big deal if you are trying to navigatethe ocean with only a compass. it was designed so that a line drawn betweentwo points on the map would provide the exact angle to follow on a compass to travel betweenthose points. if we go back into a globe, you can see thatthis line is not shortest route. but it provides a simple, reliable way tonavigate across oceans. gerardus mercator, who created the projectionin the 16th century, was able to preserve direction by varying the distance betweenlatitude lines while also making them straight,
creating a grid of right angles.. but that created other problems. where mercator fails is its representationof size. look at the size of africa as compared togreenland. on the mercator map they look about the samesize. but look at a globe for greenland’s truesize, and you’ll see it’s way smaller than africa. by a factor of 14 in fact. if we put some dot that are all the same sizeon a globe, then we projected as a mercator
map, we would end up with this. the circles retain their shape but are enlargedthe closer you get the poles. one modern critique is that this distortionperpetuates imperialist attitudes of european domination over the southern hemisphere "the mercator projection has fostered imperialist attitudes for centuries and created a ethnic bias against the third world." "really?" if you want to see a map that more accuratelydisplays size, you can use the gall-peters projection, which is called an equal-areamap.
look at greenland and africa. the size comparison is now accurate. much better than the mercator. but it’s obvious that the country shapesare now stretched. here are the dots again so you can see howthe projection preserves area while totally distorting shape. something happened in the late 60s that wouldchange the whole purpose of mapping and the way we think about projections. satellites orbiting our planet started sendinglocation and navigation data to little receiver
units all over the world. this global positioning system wiped out theneed for paper maps as a means of navigating both the seas and the sky. map projection choices became less about navigationalimperatives and more about aesthetics, design, and presentation. the mercator map, that vital tool of pre-gpsnavigation, was shunned by cartographers who now saw it as misleading. but most web mapping tools like google mapsstill use the mercator. according to google this is because the mercator’sability to preserve shape and angles makes
close-up views of cities more accurate -- a90 degree left turn on the map is a 90degree left turn on the street you’re driving down. but when trying to display something on aworld map, cartographers rarely use the mercator. most modern cartographers have settled ona variety of non-rectangular projections that split the difference between totally distortingeither size or shape. in 1998 the national geographic society adoptedthe winkel tripel projection because of it’s a pleasant balance between size and shapeaccuracy. but the fact remains, that there is no oneright projection. cartographers and mathematicians have createda huge library of available projections, each
a new perspective on the planet. the best way to see what the earth reallylooks like is to look at a globe. but as long we use flat maps, we will dealwith the tradeoffs of projections, just remember: there’s no right answer.
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