Two mathematicians have proved that a straightforward question—how hard is it to untie a knot?—has a complicated answer.

High-frequency weekly indicators provide an up-to-date forecast and nowcast of the U.S. economy, signaling changes ahead of ...

Next week sees 25 new games and bundles heading to the PlayStation platform. Fast-paced 2D action-platformer where you step into the boots of a young knight on his very first adventure. Run, jump, ...