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 called an atlas?” (later in this chapter) to find out more.
Lack of detail
Because globes entail the whole world, they tend to show less detail. Next time you’re face-to-face with the typical desktop globe, look for the region in which you live. Unless you are a resident of a big city, there’s a good chance the globe doesn’t show your hometown. And suppose you wanted a detailed map of your home area. How big would a globe have to be to include that kind of information? Probably as big as the Empire State Building. Globes are good for giving you the big picture, but if you want to view an area in detail then you better get a flat map.
Inefficient data storage
Two paragraphs ago, I mentioned a globe with a 12-inch diameter. If you want to take it somewhere, you can’t fold it up and put it in your pocket. It probably won’t even fit in your backpack. In contrast, I have an atlas that is 12 inches long, 8 inches wide, 1.5 inches thick and contains more than 100 maps. Better still, you can find all kinds of different maps via the internet. By comparison, globes are very inefficient when it comes to data storage. (Besides, it’s very difficult to walk around carrying a globe and look cool at the same time.)
How serious are these disadvantages? So serious that you’ll need to amend a pearl of wisdom you learned as a kid. Honesty is the best policy except when it comes to globes. Globes are truthful, but the truth in this case comes at a very high and bulky
