The EmDrive conceived 20 years ago by Roger Shawyer and now revisited by engineers at NASA’s Advanced Propulsion Physics Research Laboratory is an engine which generate thrust by bouncing around electromagnetic waves in a closed environment. When the generated photons collide with the closed environment walls, they start pushing the device forward without expelling anything outside, but wait, is that makes sense? Not at all, but anyway future spaceships could rely on this “impossible technology” to travel through the stars without nothing more than carrying supplies and astronauts excluding the main barrier we have now to travel to deep space, fuel.
Is this the end of physics laws as we know it? Maybe, because this behavior challenges the status quo where our conception of gravity and motion based on Sir Isaac Newton´s could be in stake, we are talking about more than three centuries where humans live with this conception, so it is no easy to believe, mainly in accordance to the third law, which is the one that defies the way Sir Newton stated as of “from every action, there is an equal and opposite reaction” and since the EmDrive is not expelling any particle at all, the momentum conservation is not conceived.