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 ...

Gravity used to be the most dependable rule in the cosmic rulebook, the quiet background force that never changed its mind. Now a series of discoveries and bold claims are turning that certainty into ...

Ever since Isaac Newton famously talked about gravity, its dominance as a force in our Solar System has been well known. It’s responsible for the orbits of the planets and their satellites but there ...

Keeping an orbiting satellite in the proper attitude is no mean trick. But there are times when antennas and cameras have to be kept pointing continually at the earth if they are to work effectively, ...