Last year, NASA's advanced propulsion research wing made headlines by announcing the successful test of a physics-defying electromagnetic drive, or EM drive. Now, this futuristic engine, which could in theory propel objects to near-relativistic speeds, has been shown to work inside a space-like vacuum. NASA Eagleworks made the announcement quite unassumingly via NASASpaceFlight.com. The EM drive is controversial in that it appears to violate conventional physics and the law of conservation of momentum; the engine, invented by British scientist Roger Sawyer, converts electric power to thrust without the need for any propellant by bouncing microwaves within a closed container. So, with no expulsion of propellant, there’s nothing to balance the change in the spacecraft’s momentum during acceleration.In addition to violating the laws of physics as we know them (maybe they aren't so much laws as guidelines), such a drive would open up the possibility of interstellar travel using energy captured from space.
But so far, the Newton's Laws, with Einstein's corrections have worked pretty well, and I'm fairly confident that this will turn out to be experimental error, and that when tried in true space, the drive doesn't work as advertised.
But just like Nessie, Chessie, Yeti and Bigfoot, I'm rooting for it.