Today we were wondering "Why don't we fall off the Earth when it is up-side down in space?" We were also wondering "Why do astronauts on the moon bounce about so much every time they take a step?".......Both these questions can be answered if we know about gravity.

On Earth if we drop anything, it falls to the ground. Have you ever wondered why this is?

Well, there is a force called "gravity" which pulls everything it can. That's why things fall down if they can.

Teacher had two identical pieces of paper. She asked us which was heavier. (We spotted this as a trick question, both weigh the same!) When we let them fall, both pieces floated to the ground at the same time. We know that it is air (air resistance) that makes the pieces of paper float in the air rather than fall straight down to ground.

Then teacher scrunched up one piece of paper and asked us again which piece of paper was heavier. (We didn't realise that this is also a trick question-the two pieces of paper are still the same weight!) This time when we dropped the paper, the scrunched up piece of paper landed first.

We were wondering if it is the weight or the shape of the object that matters when you are deciding which object falls first. We decided to test this out:

A stone and the scrunched paper are about the same shape but are very different weights. What happens if we drop these at the same time? Believe it or not they land together. Amazing!

Next we tried two water bottles, one empty, one full. We dropped these at the same time. Again they landed at the same time.