Learning about the Earth

What the Activity is for

We'd suggest that a sequence of questions focusing on the shape of the Earth is the most fruitful approach. The children will have seen globes, so they are likely to know it a sphere.

However, a very big question just has to be asked, which forms the centrepiece of this activity.

Teacher: How do you know the Earth is a sphere?

What to Prepare

• Stickers to put on the classroom window

What Happens During this Activity

Teacher: So, the big question: What shape is the Earth?

(You might like to rule out pictures from space because they could be forged, and you'd like them to rely on their own senses. You could support this by pointing out that the ancient Greek philosophers had worked out that it is sphere, long before space travel, or even photographs.)

We'd suggest that children think, pair and share so that they have time to think about this carefully.

The children may come up with all sorts of ideas – here are some actual responses from Year 5 children:

Lee: If it's flat, when you make the foundations for a temple why doesn't it go through?

Jenny: Why doesn't water fall off the edge if the Earth is flat?

Azim: Because gravity comes from the centre of the earth, because a sphere is the smallest shape you can make from the centre, it would most likely be pulled up into a sphere.

All these explorations are good but the last one is awesome and shows very advanced thinking, well beyond what you might expect for primary-age children.

Using big questions in this way is an excellent tool for formative assessment.

Convincing evidence

The most convincing evidence is something that they might never have seen:

Teacher: When a bus appears in the distance, the first thing to be seen is always the top of it.

Tell/show them this if needs be (but only after they have a good length of time to come up with their own ideas) and they can then discuss why this observation suggests that the Earth is a sphere.

Counterfactual arguments

Here is a sequence of pictures of a bus coming towards you along a flat road.

Teacher: What would the approaching bus look like if the Earth were flat?

It would look like a tiny toy which just gets bigger and bigger. The fact that the top is always visible first shows that it is coming up over the curve in the Earth's surface.

Ancient thinking

The ancients also observed that the Moon and the Sun appear to be circular and understood that a sphere looks like a disc when seen.

And so they made a connection between a disc shape and a sphere, thinking that the Earth too might be curved.