World History Toolbox – Lesson 5

Earth is a sphere; maps are flat. This poses a problem.

Have you ever tried to peel an orange and lay the peel flat? What happens?

In order to “flatten” the surface of the Earth, cartographers (mapmakers, remember?) use mathematical calculations to create a projection of the Earth’s surface on a map.

In order to make a map that is smooth and flat, cartographers have to stretch, or distort, parts of the world. All maps are distorted, but some are more

apparent than others.

Do the following for ONE of the map projections in your pile. Estimate the number of sq. cm. of water vs.

land area, and use a calculator to compute the approximate percentage on each projection.

Use the grid to estimate the number of sq. cm. of the land masses on your chart. Use a calculator to compute the area and percentages of the total global surface area and complete the appropriate boxes on your chart.

Not smooth…

How might the use of the Mercator projection in schools have affected generations of students in terms of their perception of the relative size and importance of different land masses?

Even assuming that people realize that the sizes of Greenland and Antarctica are out of proportion on the Mercator projection, how are people likely to perceive the relative sizes of Asia and Africa? Are people likely to perceive that a relative size distortion exists? Why or why not?

Equal area projections (such as the Peters projection) are quite commonly used now. How might that fact affect the geographical perceptions of the current generation of students?