Wading through lies in search of the truth
The maps in both Figure 4-2 and 4-3 are lying. But the map in Figure 4-3 provides the most accurate — that is, most globe-like — perspective regarding the shortest route between New York and Singapore. I’d really love to be able to prove that to you right here on the page of this book, but therein lies the problem — literally. This page is flat. To find out which route is shortest, you need a map that really looks like the world itself. That is, you need a globe.
Because a globe doesn’t come with this book, you have to come to grips with the four ways in which maps can lie: distance, direction, shape, and area.
Distance
Theoretically, transferring a curved Earth to a flat map involves selectively stretching some parts of Earth’s surface more than others. For example, imagine two cities are 1,000 miles apart and the land between them gets stretched a great deal during the map-making process. Now imagine that elsewhere on Earth, two other cities are also 1,000 miles apart, but the land between them gets stretched just a little to make the very same map. On the resulting maps, the distance of 1,000 miles isn’t portrayed the same.
Direction
The situation with direction is pretty much the same as with distance. By stretching a globe to make a flat map, true directions become incorrect. If some parts of the globe are stretched more than others, then a north arrow placed on one part of the map may point in a different direction than a north arrow placed elsewhere.
Actually, it’s possible to make a map that keeps true directions throughout its surface. The Mercator Projection, a rather famous map introduced later in the chapter, is an example. But maintaining true direction can only be achieved by distorting something else. As the Mercator Projection shows, that something else is distance and area.
Shape
Shape refers to the outline of objects on Earth’s surface. In the process of projection, you can transfer a continent or island from a globe to a flat surface while keeping its shape pretty intact. Then again, you can make a complete mess of things because stretching here and pulling there is part and parcel to the projection process and may play havoc with shape.
For example, compare Greenland in Figures 4-2 and 4-3. Notice that the island appears very differently in the two maps. Greenland’s shape is virtually correct in Figure 4-3 because the lines of longitude meet at the North Pole, just as in reality. In Figure 4-2, however, Greenland is seriously misshapen because the lines of longitude do not meet at the North Pole but are instead spread apart in the polar area. The result is a greatly distorted Greenland.
But before we sing the praises of Figure 4-3, compare the shape of Northern Africa on both maps. Africa appears much more accurately in Figure 4-2 because in that map, the spacing of North Africa’s lines of latitude and longitude are pretty much true to life. In Figure 4-3, however, North Africa appears to have become an accordion. It has been stretched laterally out of proportion to its true shape. That happens because as the lines of longitude extend outward from the center point — the North Pole — the projection excessively stretches the distance between them. As a result, North Africa has a flattened appearance.
Area
Area refers to the size of objects on Earth’s surface. As is the case with shape, you can transfer (project) some features from a globe onto a flat surface while keeping sizes accurate relative to other objects on Earth’s surface. Then again, you can make a complete mess of things. As to the reasons why, well, I apologize that this is sounding like a stuck record, but the simple fact is that stretching here and pulling there to make a flat map screws up the relative sizes of continents, oceans, and everything else on Earth.
Isn’t there a truthful map anywhere?
Many maps are honest. But before I point some of them out to you, let me re-emphasize that flat map untruthfulness is related to Earth’s curvature. Obviously, big portions of Earth involve more curvature than small portions.
A flat map of the entire world is going to lie a lot because so much curvature is involved. In contrast, a flat map of the United States has the potential of being more truthful (strictly geographically speaking) because the area of the United States has less curvature than the entire world. A flat map of the town or area in which you live — well, now we’re talking little fibs as opposed to big lies because your local surroundings do not have that much of Earth’s curved surface. And if we’re talking about a map of your backyard that could be an absolutely honest map because Earth’s curvature over such a small space is virtually nil.
So, yes there are honest maps, but only ones that involve relatively small portions of Earth’s surface. Geography, however, involves study of the whole Earth or portions of it that typically are bigger than your backyard. That means curvature is involved and therefore the likelihood of dealing with dishonest maps.
The one and only honest map: The globe!
A globe is a spherical map of the world. I’m almost embarrassed to write that because everybody knows a globe when they see one. But over the years, I’ve been amazed at the number of people who tell me that a globe isn’t a map because, according to them, maps are by definition flat. Not so. A globe is a representation of Earth; so, by definition, it most definitely is a map.
The globe is the one and only honest map of the world. Because the globe has the same shape as Earth, the appearance of Earth on a globe is free of distortion. Put differently, a globe doesn’t lie flat so it doesn’t lie at all (except for maybe the information displayed on or left off the globe). On a side note, globes are very attractive and fun to look at. Place one conspicuously in your home and guests are likely to think you have good taste and are very intellectual.
Honesty is the best policy, except …
Globes are truthful and the truth counts, but globes have four major disadvantages relative to flat maps.
Limited field of view
No matter how you look at a globe, you can never see the whole world at once (unless you’re in a room full of mirrors, but forget that as a practical solution). Indeed, when you calculate the geometry, you cannot see even half of the world at once on a globe. However, it’s often desirable to view Earth in its entirety or to visually compare far away parts of the world. These perspectives aren’t possible on a globe but are possible on flat maps.
High cost
Before going any further, why is this book of maps called an atlas? See the sidebar “Why is an atlas