NASA has published the article Evaluating NASA’s Futuristic EM Drive.
A group at NASA’s Johnson Space Center has successfully tested an electromagnetic (EM) propulsion drive in a vacuum – a major breakthrough for a multi-year international effort comprising several competing research teams. Thrust measurements of the EM Drive defy classical physics’ expectations that such a closed (microwave) cavity should be unusable for space propulsion because of the law of conservation of momentum.
When it comes to projects like this, science and politics often get entangled.
There are many conjectures about why this EM drive works. The most intriguing one to me that is mentioned in the article is:
On April 5, 2015, Paul March reported at NASAspaceflight.com’s Forum that Dr. White and Dr. Jerry Vera at NASA Eagleworks have just created a new computational code that models the EM Drive’s thrust as a three-dimensional magnetohydrodynamic flow of electron-positron virtual particles.
I don’t think I saw in the article what principles of physics are used in this computational code. Though, physical principles are not always necessary for computational models which can be built around fitting the model to experimental data without a complete understanding of the physics behind the data.
Well, I suppose that “three-dimensional magnetohydrodynamic flow of electron-positron virtual particles” could be considered to be the physics behind this. I don’t know how such a flow could violate conservation of momentum.
Bringing in gravity and the theory of general relativity seems unconvincing to my highly untrained physical understanding. There does not seem to be much mass to induce space/time warping to any significant degree, and to my knowledge nobody has a theory of quantum gravity yet. Unless the Higgs Boson is that quantum theory.
I leave it to Llanda Richardson and Terry Steiner to clean up all my mistakes in physics. Marden Seavy can chime in if he wants to.