Add Yahoo as a preferred source to see more of our stories on Google. Imaginary numbers push the boundaries of calculus and other branches of math. Hill Street Studios/DigitalVision via Getty Images ...

A century ago, the strange behavior of atoms and elementary particles led physicists to formulate a new theory of nature. That theory, quantum mechanics, found immediate success, proving its worth ...

Several years ago one of us, Toni, asked another of us, Marco, to come to his office at the Institute of Photonic Sciences, a large research center in Castelldefels near Barcelona. “There is a problem ...