At 03:54 PM 8/4/2014, Robert McGwier wrote:
I hope they aren't wrong because they clearly don't understand how it works!!! http://ntrs.nasa.gov/search.jsp?R=20140006052
The result is surely wrong.
When measuring MICROnewtons, from a device that's going to be getting very hot (because the microwave energy is dissipated in the walls of the cavity) you may need to do the experiment in a vacuum, to avoid air convection confusing the experiment. In any case, they say they worked on the experiment for 8 days, which is not enough time to figure out all the engineering aspects of the experiment.
They did the test in a vacuum chamber (which means they must have been thinking along the lines of my statement above about convection, but they did the test with "the door closed but at ambient atmospheric pressure". Maybe they didn't have enough time to do the tests at vacuum.
If they have resources to do more work, clearly pulling a vacuum on that chamber is the next thing to do. I predict that the thrust will disappear as the air is pumped out of the chamber.
However, of course I'm not absolutely sure its wrong. I'll be very happy if it turns out to be correct.
My bet, however, is firmly on the no side.