Your peel had a curve before it reached the table. Pressing it down may leave gaps, folds or pieces. You can move those pieces together, but the shape changes again. Keep that observation in mind when you look at a world map.

Earth has a curved surface. A globe is a round model of it. A projection is a way of showing that curved surface on a flat map. Every world-map projection changes something, such as shapes, relative sizes or distances.

Mapmakers cannot keep every property unchanged at once. They choose what matters for the map’s job. A map useful for one task may be a poor choice for another. Your peel shows the flattening puzzle, but it does not reproduce the mathematics of any particular projection.

Imagine planning a voyage and comparing the sizes of countries. Those are different jobs. A mapmaker has to decide which job a map should help with.

Gerardus Mercator developed a world-map projection for ocean navigation. On this kind of map, areas near the poles appear enlarged. A place can look much bigger beside another place than it would on a globe.

Other projections preserve relative areas while changing shapes. That does not make them perfect maps. It makes them useful for a different purpose. Before judging a flat world map, ask what you want to learn from it. A map can be carefully made and still be unsuitable for the comparison you are making.

together · About 10 minutes; untested estimate.

You need

• Orange peel or a paper shell
• Ball for the paper alternative
• Paper and pencil

Try it

1. Ask an adult to start the peel if needed. Keep a few large pieces.
2. Place the curved pieces on paper and press gently.
3. Draw gaps or overlaps without hiding them.
4. Move the pieces to close a gap. Notice another change.
5. Try wrapping them back around the orange or ball.