day and night

Light travels in straight lines so only half the world can be lit up by the Sun; the other half must be in darkness.

We say that the Sun rises in the East and sets in the West because that is what appears to be happening. But this is an illusion caused by the rotation of the Earth.

As we stand on the spinning Earth, it is we who are moving towards the East rather than the Sun moving westwards.

Stand outside on a sunny day and try imagining that instead of the Sun travelling westwards across the sky, it is YOU and the Earth’s surface that are moving eastward.

The Hindu view of the universe was even more imaginative. They believed that the Earth was carried on the back of a group of elephants, which stood on a turtle. The whole universe was encircled by a cobra. Earthquakes were thought to be caused when the elephants moved!