Whipping his racquet through the air like a cesta in jai alai, Rafael Nadal produces such tremendous topspin that the ball sometimes seems to catapult off the court, creating a shot as challenging to ...

Two masses pull a scale in different directions to measure the tension in the string. One mass can be detached and the string held in hand to simulate the string being attached to a wall. The string ...

The apparent inability of physics' string theory to be proved right or wrong is one of the stickiest – and argument-generating – problems in modern science. But now researchers at the University of ...