SpaceNASA engineer's 'helical engine' may violate the laws of physics A NASA engineer has published plans for an engine that could accelerate a rocket without using propellant. But there are questions over whether it could work News
PhysicsWelcome to the 5th dimension: Our universe's radical new fate Our best models of cosmology suggest the universe will either go on forever, implode or rip itself apart. A new proposal suggests an even weirder destiny Features