Martin Tajmar, researcher at the Dresden University of Technology in Germany, has presented new test results consistent with “encouraging results” presented by NASA’s Eagleworks research team in July 2014 at the 50th Joint Propulsions Conference in Cleveland, Ohio.
According to the Tajmar, using a version of NASA’s EM Drive, he was able to produce in vacuum measurable amounts of thrust comparable with those obtained by NASA researchers at the Johnson Space Center (JSC).
Science Alert reports that Tajmar and a graduate student Georg Fielder, presented their test results in a paper titled, “Direct Thrust Measurements of an EM Drive and Evaluation of Possible Side-Effects,” at the 2015 American Institute for Aeronautics and Astronautics’ Propulsion and Energy Forum and Exposition, held in Florida on July 27.
Admitting that the conditions under which they obtained the test results were not sufficiently exacting to confirm the claims that the EM Drive actually works, the researcher said the results nevertheless indicate need for further investigation of the cause of observed measurable thrusts.
The researchers said they plan to carry out further tests using “improved EM Drive models” under conditions that permit better control over experimental error sources.
“Our test campaign cannot confirm or refute the claims of the EM Drive but intends to independently assess possible side-effects in the measurements [sic] methods used so far. Nevertheless, we do observe thrust close to the actual predictions after eliminating many possible error sources that should warrant further investigation into the phenomena.”
But the latest claim of independent confirmation of NASA’s results has met with expected skepticism from experts in the field.
Eric Davis, a physicist at the Institute for Advanced Studies at Austin, pointed out flaws in Tajmar’s experiment and rejected the claim by the researchers that they eliminated “many possible error sources” that could explain the thrust signals measured.
“I noted in [the study’s] conclusion paragraphs that [Tajmar’s] apparatus was producing hundreds of micro-Newtons of thrust when it got very hot and that his measuring instrumentation is not very accurate when the apparatus becomes hot.
“He also stated that he was still recording thrust signals even after the electrical power was turned off which is a huge key clue that his thrust measurements are all systematic artifact false positive thrust signals.”
Davis went on to point out that the researchers made no attempt to explain the violation of the law of conservation of momentum, a failure which, according to Davis, “will cause peer reviews and technical journal editors to reject his paper should it be submitted to any of the peer-review physics and aerospace journals.”
A CalTech physicist, Sean Carroll, dismissed the EM Drive concept as “complete crap and waste of time.”
“My insight is that the EM Drive is complete crap and a waste of time. Right there in the abstract this paper says, ‘Our test campaign cannot confirm or refute the claims of the EM Drive,’ so I’m not sure what the news is. I’m going to spend my time thinking about ideas that don’t violate conservation of momentum.”
The idea of the EM Drive, first proposed by the English researcher Roger Shawyer in 2001, suggests it is possible to generate thrust from electrical energy by bouncing microwaves in a closed environment called a resonant cavity.
But the theoretical puzzle is that the novel system appears to violate the law of conservation of momentum, a basic law of physics. This explains why Shawyer faced ridicule when New Scientist published his theory paper on the EM Drive in 2006.
The EM Drive’s apparent violation of the law of conservation of momentum makes it appear a scientifically “impossible” engine.
The law of conservation of momentum requires that before you can have a thrust in any given direction, there must be a propellant that generates thrust in the opposite direction.
But in 2008, Chinese researchers at the Northwestern Polytechnical University in Xi’an, published a report claiming they had confirmed Shawyer’s EmDrive concept experimentally.
Reports that a team at Johnson Space Center’s Eagleworks Laboratories had conducted independent tests in 2014 and observed thrusts consistent with previous test results caused considerable excitement online early in 2015.
But the problem is that no one can give a theoretical explanation of how the EM Drive works and although tests have produced claims of thrust generation, there are still no peer-reviewed studies showing that the thrust produced in experiments was not the result of measurement errors consequent to some aspect of the experimental setup.
In his assessment of Tajmar’s report, for instance, Davis points out that the measured thrust could have been nothing but a thermal effect.
A NASA aerospace engineer, Marc Millis, agreed with Davis, pointing out that the experimental observation that the thrust lingered after electrical power had been turned off suggests a thermal effect.
But some sympathetic observers have pointed out the fact that Tajmar merely presented experimental results without claiming to provide theoretical explanation of the observed effect. The significance of his work simply is that he has been able to reproduce NASA’s results under more controlled conditions that account for “many possible sources of error.”
If further experimental tests show that the EM Drive actually works, theoreticians would have to look closely at the system to understand why it works despite apparent contradiction of the laws of physics.
All trained scientists will agree that experimental results guide theoretical conclusions and not the other way round. As an example of effort to allow experimental results guide theoretical conclusions, NASA’s White proposed that the thrust could be due to virtual particles in vacuum behaving like propellant ions.
And as Hacked notes, the fact that Tajmar has impeccable credentials as an experimental physicist and a track record of exposing experimental error in his field, means that his suggestion that there is need for further experimental tests of the observed phenomenon should be taken seriously.
Meanwhile, scientists have been making efforts to correct the mistaken impression given in the popular media that the EM Drive is a form of “faster-than-light” warp drive system. While scientists admit that the impact of a successful demonstration of the EM Drive could be revolutionary due to its potential ability to provide faster and more economical means of space travel, it has nothing do with the Star Trek-derived concept of the “Warp Drive.”