Chinese scientists just announced that they have successfully recreated NASA’s ‘impossible’ EmDrive, an engine that works entirely on electromagnetic radiation.
The prototype is not in a garage-filmed Youtube video, the radical technology recently stirred up controversy after a paper published by a team of researchers from NASA’s Eagleworks Laboratories in the peer-reviewed Journal of Propulsion and Power appeared to show they’d successfully built the technology.
It was said the engine could get humans to Mars in just 70 days.
The “reactionless” Electromagnetic Drive, or EmDrive for short, is an engine propelled solely by electromagnetic radiation.
This “impossible” engine appears to violate one of the fundamental laws of physics. With no fuel to eject, this tech contradicts Newton’s third law of motion, that for every action there is an equal and opposite reaction.
But now, scientists from Chinese Aerospace Science and Technology Corporation (CASC) claim NASA’s results “re-confirm” what they’d already achieved.
At a press conference in Beijing the researchers confirmed the government has been funding research into the technology since 2010, and claimed they’ve developed a device that’s already being tested in low-Earth orbit aboard Tiangong-2, IBTimes UK reports. They also said they planned to implement this engine in satellites “as quickly as possible.”
The EmDrive, first proposed by British engineer Roger Shawyer, allegedly uses only electricity to generate movement simply by bouncing microwaves around a cone-shaped copper chamber and creating radiation pressure.
No propellant goes in, no exhaust comes out. Even though the idea garnered headlines in the science press globally and even hit the the cover of New Scientist magazine, most scientists were, and still are, extremely skeptical.
The propulsion theory behind the EmDrive, explained more thoroughly:
“At first sight the idea of propulsion without propellant seems impossible. However the technology is firmly anchored in the basic laws of physics and following an extensive review process, no transgressions of these laws have been identified.
The principle of operation is based on the well-known phenomenon of radiation pressure. This relies on Newton’s Second Law where force is defined as the rate of change of momentum. Thus an electromagnetic (EM) wave, travelling at the speed of light has a certain momentum which it will transfer to a reflector, resulting in a tiny force.
If the same EM wave is travelling at a fraction of the speed of light, the rate of change of momentum, and hence force, is reduced by that fraction. The propagation velocity of an EM wave, and the resulting force it exerts, can be varied depending on the geometry of a waveguide within which it travels. This was demonstrated by work carried out in the 1950’s. (CULLEN, A.L. ‘Absolute Power Measurements at Microwave Frequencies’ IEE Proceedings Vol 99 Part 1V 1952 P.100)
Thus if the EM wave travelling in a tapered waveguide is bounced between two reflectors, with a large velocity difference at the reflector surfaces, the force difference will give a resultant thrust to the waveguide linking the two reflectors. If the reflectors are separated by a multiple of half the effective wavelength of the EM wave, this thrust will be multiplied by the Q of the resulting resonant cavity, as illustrated below.”