This week in science Year 3 have been looking at how we get day and night on our planet. Is there a giant switch that someone turns off when it’s time to go to sleep, or is there perhaps a more scientific explanation? The ancient Greeks believed that Helios pulled the sun across the sky each day in a chariot.
Everyday we can see the sunrise and set so we discussed does the sun actually move around the earth? We discovered that the sun actually stays in the same place in relation to the Earth. It appears to move because of the movements of Earth as it orbits the Sun. Earth moves in two ways. It revolves (orbits) the Sun and one revolution takes just over 365 days. It rotates (spins) on its own axis and completes one revolution once every 24 hours. From these pieces of information we deduced that the revolution of Earth (once every 365 days) causes the seasons and the rotation of Earth (once every 24 hours) causes night and day.
We also talked about how the Earth is tilted at a slight angle. Currently, this tilt is 23.5° and it can change over thousands of years. One of our classmates is in China at the moment and when we talk to her it is night time there so we discussed how we have different time zones on our planet. We will often joke and say she is actually in the future because as we are having our day she has already had hers. When we talk to her it is 1:00pm our time but it is 9:00pm her time.
We had lots of fun recreating day and night using a globe and a torch too.