"Physicists will tell you that four forces control the universe. Of these, gravity may be the most obvious, but it is also the most mysterious. Newton managed to predict the force of gravity but couldn't explain how it worked at a distance. Einstein picked up on the simple premise that gravity and acceleration are interchangeable to devise his mind-bending general relativity, showing how matter warps space and time. Not only did this explain how gravity...

"On 14 September 2015, after 50 years of searching, gravitational waves were detected for the first time and astronomy changed for ever. Until then, investigation of the universe had depended on electromagnetic radiation: visible light, radio, X-rays and the rest. But gravitational waves--ripples in the fabric of space and time--are unrelenting, passing through barriers that stop light dead. At the two 2.5 mile long LIGO observatories in the US, scientists...

For centuries scientists believed that the universe was a vast machine - with enough detail, you could predict exactly what would happen. Admittedly real life wasn't like that. But only, they argued, because we didn't have enough data to be certain. Then the cracks began to appear. It proved impossible to predict exactly how three planets orbiting each other would move. Meteorologists discovered that the weather was truly chaotic - so dependent on...