What did Newton understand that was such a revolution? Can someone just... explain gravity to me? Let's start with a ...

Legend has it that Isaac Newton had the moment of inspiration that would lead to his theory of gravity when, on a warm afternoon, he saw an apple fall from a tree and wondered why it should fall ...

Isaac Newton - isn't he the guy who discovered gravity? Great! So, what's gravity? Aaaah, gravity is the force that makes objects fall towards the ground. And, without gravity, we'd all float!

The moon, is only a quarter the size of the Earth. Gravity holds it in an ongoing embrace, its orbit taking nearly 27 and a half days to complete. The planet Earth is about 4.5 billion years old.