EmDrives: The End of Newtonian Physics?

Peter Selness, MJLST Staffer

The EmDrive has been the center of much controversy over the past decade, and rightfully so.  But what exactly is an EmDrive, and why does it have the scientific community at odds with one another over the underlying science behind it?  The EmDrive is a type of propulsion system that was first designed by Roger Shawyer in 2001.  Essentially, it is a RF resonant cavity thruster that relies on electro magnetic radiation projected into the cavity of a cone to produce thrust.

The EmDrive was met with no small amount of criticism when first proposed because it is what is known as a propellantless propulsion system in that it consumes no fuel when producing thrust.  Not only does it consume no fuel, however, it also appears to only produce force in one direction, thus contradicting Newton’s third law of “for every action there is an equal and opposite reaction.”  Such a proposition has been compared to standing on the deck of a sailboat and pushing on the mast to propel it across a lake, or the old adage of “pulling yourself up by your bootstraps.”  The implications of such a device means that our understanding of physics as it relates to Newton’s third law (which has been relied upon for centuries) is either not entirely understood yet by humanity, or is completely wrong; which is largely why the EmDrive has received such criticism from the scientific community.

And yet, there are multiple confirmed reports of EmDrive testing resulting in this unexplainable thrust that have arisen independently from Roger Shawyer.  Even NASA conducted testing on EmDrives in 2014 and reported measuring a thrust produced by the device.  A similar experiment was then carried out by NASA again in 2015 to correct for some reported errors from the first test, but thrust was surprisingly recorded again despite the corrections.  Also, an EmDrive paper has finally been accepted by peer review by the American Institute of Aeronautics and Astronautics, granting the technology more authority from critics.

Interestingly enough, legal developments have also granted significant legitimacy to the EmDrive.  Roger Shawyer currently has three patents granted on the EmDrive, while two more are still going through the patent process.  Being granted three patents from the UK IP Office means that the physics behind the EmDrive has been thoroughly examined and was found to not violate the laws of physics, as such a violation would inevitably have lead to the patent applications being denied.  Furthermore, Shawyer’s most recent patent, as of October 12th, was filed more than 18 months ago, allowing the patent office to disclose the information contained to the public.  Such a public disclosure should in turn allow for greater scrutiny of Shawyer’s more recent efforts in developing the EmDrive.

The implications of the EmDrive being accepted as a legitimate technology are immense.  First of all, a working propellantless propulsion system would allow for future space craft to be much lighter and cheaper without requiring large amounts of rocket fuel for each take off.  It also would allow for much faster space travel, possibly allowing humans to reach the outer limits of our solar system in a matter of years and Mars within only a few months.  Furthermore, outside its space propulsion systems applications, there’s really no limit to what it may be applied to.

Despite passing several hurdles in recent years, however, the EmDrive is still a long way from leading us to interstellar travel.  The testing conducted by NASA, while showing positive results, also recorded thrust of a force just slightly higher than the magnitude of error for the experiment.  Also, while this positive result allowed it to pass peer review, that does not necessarily mean that the technology is sound and will not later be found to have flaws.  In all likelihood, the chances of a new technology being discovered that, for the first time, violates the laws of physics as we have known them for hundreds of years is a far less likely result than finding some sort of experimental error in the technology.  But maybe, just maybe, this could be the end of Newtonian physics as we know it.