One of the ultimate dreams of humans everywhere is limitless, free energy. It's the ability to do the impossible: to pull power out of empty space itself; to create a device that spins faster-and-faster without an energy source; to accelerate a rocket without any fuel or propellant. Yet the laws of physics have always stood in the way.

A few years ago, a few renegade inventors emerged with another incarnation of this idea, in the form of a device called an EmDrive. This electromagnetic cavity claimed to be an engine that required no fuel and emitted no exhaust. It simply required input power, and could convert that energy into thrust. This would violate the laws of physics, but the experiments seemed to indicate that it worked.

Until now, when a team led by Martin Tajmar has exposed what's really going on behind-the-scenes. This purported "impossible" space engine, as it turns out, really is too good to be true.

Good pedagogical explanation why it won't work as hyped.  To read more, click here.