Describing movement(Introduction)

Natural and unnatural descriptions

Ideas about movement and speed are part of the language and experience of most children. But, without thinking, they tend to assume that they're at rest and everything moves around them. This is common sense, but can be deceptive. That's particularly true when thinking about astronomical movements.

It's easy enough to imagine that the Moon orbits around the Earth, although somewhat harder to explain why the appearance of the moon changes.

It's altogether harder to imagine that the Earth is orbiting around the Sun and that the Earth is spinning on its axis. Yet you'll need these two to make sense of the motion of the astronomical objects (stars and planets) and to account for day and night.

So its worth taking care to explicitly select a point of view, so laying firm foundations for clear thinking in the future.