Peer-reviewed NASA “EM drive” report draws media enthusiasm and doubt
DOI: 10.1063/PT.5.8198
Journalists and commentators got a new physics-reporting challenge in November: not neutrinos purportedly exceeding the speed of light, but a peer-reviewed NASA paper claiming in-principle confirmation of an electromagnetic (EM) drive system that seems to violate physical law. In general, media coverage has happily celebrated the apparently revolutionary possibilities, but has also stipulated forthrightly the importance of skepticism.
After an earlier round of EM drive excitement in 2014—before peer review became a factor—investments expert Clem Chambers captured the excitement by declaring at the business site Forbes.com that if “there is a get around to Newton’s Third Law,” even the internet is going to look small. “Inventing a time machine would be more dramatic … but not a lot more,” he enthused. “A force engine would be like inventing fire.”
The extraordinary claim comes from principal investigator Harold G. White’s team of NASA research engineers in Houston, Texas, at Johnson Space Center’s ambitious Eagleworks Laboratories. NASA established Eagleworks in 2011 “to pursue propulsion technologies” and to enable “interstellar spaceflight by the end of the century.”
In 2014, the abstract for a not-peer-reviewed conference paper by White’s team began by reporting testing “classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the quantum vacuum virtual plasma.” It noted that the team would “not address the physics of the quantum vacuum plasma thruster,” but instead would describe the testing of equipment, which came from Cannae LLC of Doylestown, Pennsylvania.
The abstract stated that “approximately 30-50 micro-Newtons of thrust were recorded from an electric propulsion test article consisting primarily of a radio frequency (RF) resonant cavity excited at approximately 935 megahertz.” It included something certain to incite media interest: “Test results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.”
This electromagnetic drive system produced dozens of micronewtons of thrust, according to a recent peer-reviewed study.
H. White et al./Journal of Propulsion and Power 2016
The more recent round of EM drive excitement stems from White’s team’s 2016 peer-reviewed paper “Measurement of impulsive thrust from a closed radio-frequency cavity in vacuum.” It appears in the Journal of Propulsion and Power from the American Institute of Aeronautics and Astronautics. Here’s how it opens:
It was previously reported that radio-frequency (RF) resonant cavities generated anomalous thrust on a low-thrust torsion pendulum in spite of the apparent lack of a propellant or other medium with which to exchange momentum. It is shown here that a dielectrically loaded, tapered RF test article excited in the transverse magnetic 212 (TM212) mode at 1937 MHz is capable of consistently generating force at a thrust-to-power level of 1.2 ± 0.1 mN/kW with the force directed to the narrow end under vacuum conditions.
In some cases, the news has drawn enthusiastic effusions.
Mirror.Co.UK calls itself “the online edition of The Daily Mirror, Britain’s brightest tabloid newspaper.” In 2015 it reported that the US National Aeronautics and Space Administration—which it mistermed the “North American Space Agency"—is building a “real life warp drive,” a fictional faster-than-light spacecraft-propulsion system. In November 2016, the Mirror reported that NASA had built “a working ‘warp drive.’”
ScienceAlert proclaimed that “the controversial propulsion system really does work, and is capable of generating impressive thrust in a vacuum, even after error measurements have been accounted for.” Headlines and Global News told readers that EM drive had not just received peer review, but “peer approval.”
Peer approval? Several media organizations explained that peer review is only peer review. At National Geographic, Nadia Drake and Michael Greshko, who formerly wrote for Inside Science news service at the American Institute of Physics, reminded readers that peer review “doesn’t guarantee that a finding or observation is valid.” Similar reminders and explanations appeared from the Economist , Discover , the Christian Science Monitor , the Daily Caller , the Inquisitr , Forbes , and Wired .
The fact-checking site Snopes.com, recognizing the public importance of the peer-review factor, published a clarifying article under the headline “Results of ‘impossible’ EmDrive propulsion experiment published in peer-reviewed journal.” Snopes concluded, “The fact that they were able to publish their results in a peer-reviewed journal is a great leap forward for the team, but the peer review process does not mean the results are necessarily valid.”
Snopes took a decidely skeptical view overall, as telegraphed in the subhead “Depending on which of the many explanations you prefer, this propulsion system violates myriad laws of physics, leaving many skeptical of the findings.” The article derived in part from a strongly skeptical Ars Technica commentary by physicist Chris Lee, whose subhead observed, “New paper generates more noise than experimental thrust.”
Lee’s piece opened by disdaining the EM drive as a “zombie incarnation” with “all the best features of a new technology: it generally violates well-established physical principles, there is a badly outlined suggestion for how it might work, and the data that ostensibly demonstrates that it does work is both sparse and inadequately explained.” Lee also wrote, “I know that I sound a bit flippant and dismissive of this work. I promise you that I went into this paper determined to be skeptical but positive. Unfortunately, all of my positive thoughts drained through the gaping holes in the paper, leaving me at skeptical and exasperated.”
In May 2015 and again almost a year later , Popular Mechanics also offered skepticism. Science writer John Wenz predicted, “The next few months could bring an end to this silly episode in hyperbolic research. Of course, there’s the small-fraction-of-a-chance that it could survive the peer review process, at which point it maybe, just maybe … has a ghost of a chance of being a reality.” The magazine reported in September that the Eagleworks research was being peer reviewed and that “most believe that it will fail.”
But despite widely seen readiness to question the Eagleworks work, a certain cheery optimism has pervaded the media coverage too. Cornell engineering professor and former NASA chief technologist Mason Peck captured it in a brief Newsweek commentary that began this way:
NASA’s Sonny White and his collaborators have published experimental confirmation that the so-called EM drive produces thrust. If this technology fulfills its promise, it will transform public and private space exploration and may have even broader implications for terrestrial power and energy.
Their paper explains why this work is important with typically understated academic language: “For missions with very large delta-v requirements, having a propellant consumption rate of zero could offset the higher power requirements.” Let me say it another way for everyone else: wouldn’t it be great to travel in space as fast as you want without even using fuel?
The what-ifs that these questions inspire in us are why we find technology at the edge of science fiction so appealing. I suspect that they also inspire the engineers at Eagleworks. Narratives about our future break us free from the tyranny of everyday life and give us permission to imagine a better future for ourselves and the world, if only briefly. That’s part of the appeal of Star Trek and other optimistic takes on the future. It’s little wonder that White’s advanced propulsion research provided the real-world basis for the spacecraft in the current Star Trek reboot.
Peck continued to extol the idea of “revolutionary discoveries":
I suppose that as an academic, I am expected to counsel everyone to proceed with caution. We don’t know exactly why this strange device appears to propel itself by bouncing electromagnetic waves around inside a closed cavity. I should remind people that the basic idea of the EM drive violates the fundamental principle of conservation of momentum. I should point out that White’s speculation that the radio-frequency energy in the EM drive interacts with the quantum vacuum has not been confirmed in peer-reviewed research. In response to their claim that there is no experimental reason why this should not work, I should say something like, “absence of proof is not proof of absence.”
And I should point out that we’ve been burned before. Remember “cold fusion” from the 1980s? Remember more recently, in 2011, when CERN startled the world by announcing that its scientists had detected a particle traveling faster than light? The internet exploded with enthusiastic designs for faster-than-light spacecraft. It turned out that CERN’s measurements weren’t perfect, and the fiber-optic timing system had just enough unexpected error to lead them to this false conclusion. So, we don’t have faster-than-light technology—yet.
But I’m just not that kind of academic. In my own research, I much prefer “yes if” to “no because.”
Articles sharing Peck’s outlook appeared at the Washington Post , the UK’s Daily Mail , the New York Post , Space.com , and the International Business Times .
Often but not always along similar lines, Forbes has regularly posted articles about EM drive, with authorship regularly by astrophysicists Brian Koberlein of the Rochester Institute of Technology and Ethan Siegel of Lewis and Clark College in Portland, Oregon. In a May 2015 piece , Siegel called Eagleworks principal investigator White “notorious for making extraordinary claims about warp drive and fictitious physics.” Siegel invoked an aggressively skeptical 2014 analysis in Discover magazine that included this: “Being skeptical about a delicious story like this isn’t much fun, but it is essential if we are going to make real progress in space exploration. Marc Millis, who for years directed the Breakthrough Propulsion Physics program at NASA’s Glenn Research Center, calls things like the EmDrive ‘idea zombies,’ because they keep returning even when objective evaluations do not back up their claims.”
Popular Mechanics and others including ScienceAlert have reported plans to seek objective evaluation in space. Cannae has announced it will launch, possibly as early as 2017, its EM drive “thruster on a 6U cubesat … the size of a small shoebox.” The idea is to keep it “on station for at least six months” because the “longer it stays in orbit, the more the satellite will show that it must be producing thrust without propellant.”
Physics and astronomy professor Siegel contributed a Forbes piece explaining “how physics falls apart” if the EM drive works. His ending would be widely understood by many who have reported and commented:
If you remember faster-than-light neutrinos, the BICEP2 results of gravitational waves from inflation, claims of cold fusion, perpetual motion or any other set of results that were later overturned with more and better data, you’ll recall that this is far from a slam-dunk. The theoretical claims of how this could work range from easily disprovable to highly speculative, and they all have no evidence except this one engine to show for it.
The point isn’t that physics is wrong, nor is the point that the Eagleworks team is wrong. The point is that this is the beginning stages of actual science being done to examine an effect. The most likely outcome is that momentum really is conserved and there’s something funny going on here. For faster-than-light neutrinos, it was a loose cable. For the BICEP2 results, it was an incorrect calibration of galactic gas. For cold fusion, it was a poor experimental setup, and for perpetual motion, it was a scam. No matter what the outcome, there’s something to be learned from further investigation. Whether it’s new physics and a new type of engine results, or whether it’s simpler than that and the effect’s cause simply hasn’t been determined yet, more and better experiments will be the ultimate arbiter. This is why we do the science in the first place.
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Steven T. Corneliussen, a media analyst for the American Institute of Physics, monitors three national newspapers, the weeklies Nature and Science, and occasionally other publications. He has published op-eds in the Washington Post and other newspapers, has written for NASA’s history program, and was a science writer at a particle-accelerator laboratory.