In this workshop you will use whole sky movies
to help you understand what different people around the world experience as our planet spins once every 24 hours. The following sections will guide you through different aspects of the relationship between Earth's rotation, orbital path
towards the Sun.
Day and Night
We get day and night because the Earth is spinning, making the Sun appear to move across the sky. The following steps will demonstrate that this has to be the case, and that it's not the Sun moving around the Earth.
- Watch the March in Europe movie a few times.
- You will see that the stars and planets all move in the same way as the Sun.
- Now stand up and slowly spin around a couple of times with your eyes pointing straight ahead.
- You will see that everything in the room (near and far) also appears to move at the same speed.
- Because you can be certain that it's you moving, and not the room, the same can be said for the spinning Earth.
When it is daytime in the UK, it can be in the middle of the night somewhere else in the world. Because of this, people in different parts of the world have their clocks set to different times. The following steps show what would happen if we all set our clocks to the same time - e.g. the time in the United Kingdom, known as GMT.
- Watch the March in Europe movie again and try to pause it at 12:00 GMT.
- Do the same for the March in North America movie.
- Is it day or night in each place? Remember, the clocks in both movies show UK time (i.e. GMT).
- You can see that day and night come at different times around the world.
- Going by the time in the UK, is sunrise earlier in North America or in Europe?
- Do you think it would be earlier or later in Australia?
Seasons occur because the Earth is tilted towards or away from the Sun. If you are not sure how this works, find out here. The tilt makes the Sun appear higher in the sky in Summer and lower in the sky in Winter. The following steps will help to re-inforce these ideas.
- First watch the June in Europe movie a few times.
- Now watch the December in Europe movie.
- You will see that the Sun stays close to the horizon in the Winter.
- This is because the northern part of the Earth is tilted away from the Sun.
- Next watch the June in Australia movie.
- How does it differ from the June in Europe movie?
- Did you note that the Sun is to the north at mid-day, rather than to the south - as we see it in the UK.
- What do you think the Movie for December in Australia will be like? Click here to see if you are right.
Places where the Sun doesn't shine
In some parts of the world, there are days, or even months, where the Sun does not rise and others where it does not set. Where do you think these places might be? Take the following steps to discover where the Sun doesn't shine.
- Watch the December in the Arctic movie a few times.
- Have a think about the tilt of the Earth and try to explain what you saw.
- Now watch the June in Antartica movie.
- Has anything changed? Can you see why this is the case?
- Can you think of anywhere in the world where the Sun might stay up all day?
- Click here or here to find out the answer.