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 down ...

The idea is still new and requires a lot of assumptions in its calculations to make it work. Over the years, experimental results have been mixed. When you purchase through links on our site, we may ...

Have you ever wondered why when you throw something into the air it falls straight back to the ground? This is because of gravity, an invisible force which acts on objects, pulling them towards the ...