The EM Drive: Is It for Real?

This weekend, I read the recently published paper on NASA’s “impossible” EM drive. Or rather, I read about the “closed radio-frequency resonant cavity” designed and tested by Eagleworks Laboratories (which is part of NASA).

Basically, this closed radio-frequency thing is a box with radio waves bouncing around inside it. Because of the box’s unusual shape, the radio waves end up pushing more on one side of the box than the other, which generates thrust. Supposedly. Even though that violates conservation of momentum.

This post is a review of the paper itself, and nothing more, because I’ve found that responsible scientists and quack scientists often reveal themselves in the way they write their papers. And whatever else might be going on with this physics-defying new engine design, the paper does not appear to be quack science.

• Experimental methods and equipment are documented in meticulous detail, and sections are included describing “force measurements procedures” and “force measurement uncertainty.”
• The researchers appear to be presenting all of their data, or at least they don’t appear to be deliberately hiding anything. They also make a point of explaining the data analysis techniques they used.
• There’s a lengthy section on potential sources of experimental error. The paper explains how each possible error was corrected, or it tells us why the researchers believe the error is not statistically significant. The important thing is that these possible experimental errors are acknowledged to the reader.

Now I’m not a scientist or an engineer, so I can’t personally evaluate the data being presented here. But the fact that the Eagleworks team share so much information and go into such extensive technical detail is a good sign (even though it makes for rather dull reading).

It means they’re not asking us to just take their word for it. Anyone with the necessary knowledge, resources, and technical skills could evaluate the data for themselves or attempt to recreate the experiment in order to independently verify the test results. And that’s how science is supposed to be done.

That does not necessarily mean the EM drive works. A paper like this should be seen as the opening of a conversation. The Eagleworks team discovered something. Something that seems to violate conservation of momentum, or perhaps undermines the Copenhagen interpretation of quantum mechanics.

Follow up papers will continue the conversation, most likely by investigating those possible sources of error the Eagleworks team mentioned, or by trying to find sources of error the Eagleworks team may have overlooked. And my guess is that the conversation will end at that point.

But if it turns out the EM drive really does work, if the test results can’t be explained away by an experimental error, then the conversation will move on to trying to figure out what’s wrong with our current understanding of the laws of physics.

Regardless of how this plays out, it’s always good to see real scientific discourse in action.