2 0 1 7 L D S H E Y O U T H E D U C A T I O N C O N F E R E N C E

How Maps Lie David Glassett \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Objectives:

- • A map that distorts area will mean that • A map that distorts area will mean that two areas (countries, parks, islands, etc.) that are the same size on a globe are not the same size on the map. This is a very common distortion. Think of Greenland. How large do you think it is in comparison to South America? About the same size? Maybe a little smaller? Can you believe it is only one-fourth the size of Brazil? Most maps we see make it look huge because they distort area in favor of some other attribute.
- • you to understand how the mapmaking • you to understand how the mapmaking process requires a cartographer to make compromises that may affect the "truth" of the information displayed.
- • you to be able to critically assess a map and • you to be able to critically assess a map and understand how the information shown may or may not tell the whole story.

EXERCISE 1: Draw a line on the map of the shortest distance possible between Williamsburg and Rome. Did you really draw the shortest distance? Maps have three basic elements: projection, scale, and symbolization. We just demonstrated how the first element, projection, can cause maps to lie.

- • A map that distorts shape will mean that • A map that distorts shape will mean that how something looks on the globe will not be the same as how it looks on the map. Instead it will be squished or elongated or warped in some way. Most maps that preserve area do so at the expense of shape.
- • Like we saw in the first exercise, the • Like we saw in the first exercise, the shortest distance on a map is not always the shortest distance in real life. That's because distance is a very difficult attribute to preserve in a map. It can be done, but usually only from one point or along one line of the map.

## PROJECTION

Projections are the inevitable need to distort information because you're taking a three-dimensional object (the Earth) and trying to represent it in two dimensions (a flat piece of paper or screen). EXERCISE 2: Find a partner. One person blows up a balloon and holds it (don't tie it!). The other person draws a large face on the balloon. Gently let the air out. Take a look at the face you drew. What happened to it? When you have the round earth projected onto a flat piece of paper, that's a map projection. You can imagine a light bulb in the middle of a clear globe with lines on it for country outlines. When the light is on, it projects the light out into a room. If you were to hold that globe close to a chalkboard, you could trace the projection of the lines onto the board, and you would have a flat map. That's how cartographers make map projections, except it's all done using very high-level trigonometry. In the process of creating a projection, you are going to distort one of four things:

- • The ability to take a compass bearing • The ability to take a compass bearing from your location to your destination and to actually arrive where you planned on was very important to sailors in the age of exploration. They created maps that preserve direction (usually at the expense of area).

MAP READER BE AWARE: The cartographer chooses the projection of the map you're looking at. It can be chosen carefully or carelessly. Think about what you're seeing. EXERCISE 3: Draw a map of how you get from your house to your church. Why didn't you draw every bush, sidwalk crack, and fire hydrant on your map? The second basic element of a map is scale.