Does the world revolve around Toronto, as this map seems
Leonard Guelke created this projection to tell you exactly
how far it was from anywhere on Earth to Toronto, Ontario,
Canada. Draw a straight line on this map from Toronto to
anywhere in the world and, with some simple math, you've got
the real-world distance. In order to achieve this benefit,
you need to sacrifice some shapes and sizes.
Look at this map. Take a second look, a good look. What do
you think of it? Would you call this is an accurate map of
the world? If you think it is, why? If you do not, why not?
If you recognize North and South America, do you also
recognize Africa? How about Australia? Let's get really
specific: trace Australia's shape onto a separate sheet of
paper. Leave the name off. Show it to some friends–how many
people looking at this do you suppose are going to say, "Of
course that's Australia–anybody would recognize it"? Why
would an honest mapmaker–in this case, Leonard Guelke–make a
map that distorts some land masses so severely? Now note
another feature of the map. The circles marked 2500 miles,
5000 miles and so on, all center on Toronto.
As you know, on a map, to show one truth you have distort
another. On any map of the world "something has got to
give." A world map that correctly shows distances from a
central point must sacrifice other qualities. Which?
Accuracy of some shapes, as we have just demonstrated with
the tracing of Australia. Precise sizes for another. Compare
Australia and the United States: which looks larger? In
spite of what this map seems to tell us, Australia really
covers 3,000,000 square miles; the United States, 3,360,000.
This map has limitations even with regard to distance. You
can accurately measure the distance from Toronto to, say,
Paris, France or to Caracas, Venezuela, but not between
Caracas and Paris. The given scale does not apply. The only
constant distances are those from Toronto. That's what the
map claims. That's exactly what it delivers.
Is this a good map? Actually, it is a very good map–for a
very limited purpose. But as soon as you try to make it do
something it was not intended to do, you have created a
problem. Note the language: the map doesn't create the
problem, the user does.
This image is taken from
Maps: The Power of Images to Shape Our World View
by Ward L. Kaiser and Denis Wood. This book looks closely at
the images and messages of maps. Chapter One is titled "The
Multiple Truths of the Mappable World" which can be
downloaded at no charge. You can also order copies of
"Seeing Through Maps" from our site.