Try providing proof that a space rocket might go through space without using any fuel, seemingly defying the rules of physics in the process, if you're a NASA researcher looking to incite an online uproar. Even if it did exist, the Starship Enterprise could not do that trick. But that is essentially what the Eagleworks Laboratories of NASA researchers performed. Researchers at Eagleworks, a division of the Johnson Space Center in Houston, recently published a paper titled "Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum" in the peer-reviewed Journal of Propulsion and Power.
An electromagnetic drive, often known as an EM drive, was tested experimentally, as described in the article. The electromagnetic drive (EM drive) is an asymmetrical chamber in which microwave photons are made to bounce about, as was first proposed by British physicist Roger Shawyer roughly 15 years ago. Contrary to a typical rocket engine, no propellant is burnt, and no exhaust escapes from a funnel. The EM drive shouldn't be able to move objects forward based on our current understanding of how the physical universe functions. Listen to this FW:Thinking podcast for some context:
"A working EM drive would violate Newton's third law of motion, relativity, Noether's theorem and a host of other extremely fundamental theories of physics," says Rochester Institute of Technology astrophysicist and author Brian Koberlein via email. "We'd basically have to rewrite physics from scratch."
However, if the findings from NASA experts are to be accepted, the EM drive may actually function. Why the concern about something that is only theoretical? If the EM drive is functional, a trip to the moon would only take a few hours, a trip to Mars would take less than three months, and a trip to Pluto would take less than two years. In the experiment, the device was mounted on a torsion pendulum, put in a vacuum-like environment resembling space, and then turned on. The measurements show that for every kilowatt of input energy, the gadget produced roughly 1.2 millinewtons. That's a lot more powerful than the 6.67 micronewtons produced per kilowatt by solar sails, which are now the most popular form of long-distance space propulsion.
It's unclear exactly how the EM drive accomplished this. The NASA scientists appear to imply in their report that the microwave photons are rubbing up against a quantum plasma, which contains transient particles. James Woodward, a physicist at California State University Fullerton, expressed questions about the idea in an email. According to him, the article by NASA researchers "does not advance the theoretical hypotheses that pretend to explain the development of thrust in these cavity based devices." Woodward emailed along a copy of an article he and colleague Heidi Fearn recently published in the Journal of the British Interplanetary Society, which describes why the plasma notion won't work. "That is, the 'radiation pressure' and 'quantum plasma' proposals are not advanced by the results described."
Woodward, who claims to have known one of the NASA researchers, Paul March, for almost 20 years, is skeptical of the EM drive's underlying theory but was impressed by the caliber of the experimental work that showed the gadget produced thrust. The claimed thrust "passed a lot of tests that should have accounted for everything noticed," the author claims. "It was done carefully with enough resources." Anomalies are the possibility for intriguing developments, therefore this elevates the experimental result to the level of a "anomaly," at least until a technique to account for it that makes sense is discovered.
Koberlein, though, is still not persuaded of the significance of the study. The judge of truth in science, he claims, is a crystal-clear experimental outcome. The EM drive "would be one of the great inventions of history," according to Koberlein, if it turns out that further research demonstrates that it does in fact work. "I don't think the team has remotely good evidence yet. they've taken a first step with a peer-reviewed article, but I don't think it justifies spending public money on it at this point," he said.