NASA's prototype EmDrive at its Eagleworks Lab. (Image courtesy of NASA.)
Known as the EmDrive, the controversial propulsion system is said to use electromagnetic waves to generate thrust. The biggest controversy surrounding the system is that it appears to violate Newton’s Third Law of Motion.
According to the third law, every action has an equal and opposite reaction. Because the EmDrive doesn’t emit any propellant, it appears to contradict one of Isaac Newton’s fundamental laws.
First theorized over a decade ago, the concept underpinning the EmDrive states that electromagnetic waves generated by stars like the Sun can be harnessed inside the drive's chamber, bounced around in a manner directed by the chamber's geometry, and expelled out the business end of drive producing thrust.
Sounds perfect, if a bit implausible, doesn’t it?
In a paper that will be published in the Journal of Propulsion and Power this December, researchers at NASA’s Eagleworks Lab have found that, in a vacuum, the test drive “was consistently performing at 1.2 ± 0.1 mN/kW, which was very close to the average impulsive performance measured in air".
Though the paper does seem to point out that the EmDrive is capable of generating thrust, there haven’t been any conclusions made about how the drive works.
One explanation that’s been making the rounds in the physics community is that the EmDrive takes advantage of pilot wave theory, which is an example of the hidden variable theory, an interpretation of quantum mechanics that is both mind-bending and “non-mainstream”
Essentially, pilot wave theory flies in the face of current interpretations of quantum mechanics by insisting that particles do have a precise position whether they’re being observed or not. If you’re familiar with the ideas of quantum entanglement or Shroedinger’s paradoxical, and murderous thought experiment , you’ll know that quantum elements only find a fixed position when they’re observed.
That fundamental disconnect has led many in the physic community to believe that the EmDrive will never work.
In the coming months the EmDrive is slated to be tested in off-world. If the drive can reproduce, or better the results that were achieved in the forthcoming study, then it might lead to not only a new propulsion system, but a rethinking of how we understand the Universe on its smallest scale.
Check out this video for a great explanation of how the EmDrive should work:
For more impossible engineering, find out how one company claims it generates more than one million Watts of power.