The history of modern physics contains several examples of crazy and successful new ideas. Unfortunately for scientists at NASA’s Johnson Space Center in Houston, their “impossible” space engine may not be one of them. Why? Simply put, it violates Isaac Newton’s third law of motion.
NASA’s experiment involved placing a radio antenna inside of a sealed, metal container. Once turned on, radio waves produced by the antenna caused the container to move very, very slightly. This result obtained without systematic error would mean that satellites, manned vehicles, and other devices traveling through space could be powered by electricity generated using solar panels instead of by combustible fuel. However, it is highly unlikely that this was the case, since Maxwell’s laws of electrodynamics and Newton’s laws of mechanics all forbid a closed box from propelling itself in one direction without ejecting matter or energy in the opposite direction. These laws are considered fundamental because they remain true despite technological advancements and human innovation.
A closer look at NASA’s original report reveals one potential source of error in that their experiment was performed at atmospheric pressure. Shimon Kolkowitz, a graduate student in Physics at Harvard University, speculates that if the tests were truly performed at atmospheric pressure, the observed force could have resulted from air currents generated from asymmetric heating of the container. Péter Kómár, a graduate student in the same department, also points out that NASA failed to propose a new theory to explain their results. This, by definition, prohibits any logically thinking scientist to talk about “breaking” our time-tested loyalties to Newton.
But don’t rule out rockets powered by radio waves just yet. Photons (including radio waves) do carry small amounts of momentum, and have been demonstrated as a feasible way to propel an object through space without violating the basic tenets of physics (see below for more information on “solar sails”). It’s just that NASA’s new physics-defying device will need to be placed under substantial scrutiny, and independently verified by other groups using different experimental techniques, before it is taken seriously.
Acknowledgments: Many thanks to Harvard Physics graduate students Shimon Kolkowitz and Péter Kómár for their expertise and detailed insights on the topic. Additional thanks to Jonathan Las Fargeas, a graduate student in Aerospace Engineering at the University of Michigan, and to Dr. Gregory Kestin, a physicist at Harvard University.
Managing Editor: Laura L. Smith
From NASA’s “Impossible” Engine Creates Controversy Among Scientists (original article)
Why NASA’s Physics-Defying Space Engine Is Probably Bogus (opinion piece)
SolarSailWiki (solar sail info)
World’s Largest Solar Sail to Launch in November 2014 (solar sails in the news)