Children ask, taz answers: Is the earth round or oval?
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We want to know from children what questions concern them. We answer one every week. This question comes from Yara, 4 years old.
In the middle, at the equator, the Earth is a little wider than at the poles Photo: imago
If you look at photos of the Earth or a globe, the Earth looks round. It is a sphere that orbits the sun just like the other planets. But why is that so?
It’s because of gravity. This is the same force that causes an apple to fall to the ground when you let go of it. When the Earth was formed, there was only dust and rocks around the sun. Gravity attracted the larger pieces of rock to each other and little by little the earth was formed.
The pressure on the chunks was so great that they became hot and liquid. This liquid material was able to spread easily and gravity caused it to become a sphere: if a piece stuck out somewhere, it was attracted to the rest. Until the surface of the earth was smooth and round.
The ancient Greeks
You may have heard that people in the Middle Ages thought that the earth was flat. But that’s not correct. In reality, people back then already knew that the earth was round.
Even the ancient Greeks many thousands of years ago suspected this. It was harder for them back then than it is for us today: We can send satellites and people into space and see the Earth from above. Back then they could only look at the sky from the ground.
But the ancient Greeks had a trick that could help you see that the Earth is a sphere: Next time you’re by the sea, watch a sailing ship heading toward the horizon. At some point the hull disappears first. But you can see the sails for much longer. Precisely because the earth is round and not flat.
This text comes from the weekday. Our weekly newspaper from the left! Every week, wochentaz is about the world as it is – and as it could be. A left-wing weekly newspaper with a voice, attitude and the special taz view of the world. New every Saturday at the kiosk and of course by subscription.
500 years ago, a ship from Portugal named “Victoria” sailed around the world. That took several years back then. This circumnavigation proved that the earth is really round.
But wait, it’s not completely round. In the middle, at the equator, the Earth is a little wider than at the poles. Like a ball when you take it in your hands and squeeze it slightly from above and below. This is due to centrifugal force. You’ll notice it when you ride the chain carousel.
When the carousel spins, the seats float. And you feel like you’re being pushed outwards and flying away. This also happens with the earth. Because it turns around once every day, it is a little more bulbous in the middle.
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