The EmDrive

Roger Shawyer conceived of a new method of propulsion some years back. It involved moving particles around in a chamber . . . well, let me allow Mr. Shawyer to explain it more fully: "Thrust is produced by the amplification of the radiation pressure of an electromagnetic wave propagated through a resonant waveguide assembly."

Exactly.

Well everyone has ignored the new method of propulsion since it seems to violate certain laws of physics. Which basically says that in a closed system the momentum is constant. Like here:

But Mr. Shawyer retorts that it does not. To add to the discussion enter the Chinese, they have said they created a EmDrive in a laboratory and that the principle works. But now to make it even more crazy, NASA has replicated the experiment.

Granted they only achieved a very small amount of thrust but, it means, if it works, that space travel will not require fuel. Ships can generate it as they travel.

Now that is pretty damn cool. Emdrive.  Article at Space.com