For several years, scientists have been discussing the “impossible engine” EmDrive, which gives “extra” cravings that come from nowhere. He was repeatedly tested, as ordinary enthusiasts, and
scientists from NASA . Each time it turned out that the engine is at least a very small draft, but it gives. And this every time caused surprise and incomprehension of experts.
The other day it became known about the results of testing the "impossible" engines (not only EmDrive) by scientists from the Dresden Technical University. The results are disappointing for those who were already going to fly to EmDrive to the stars. The scientists who conducted the experiments are confident that the thrust is due to poor engine shielding.
EmDrive was introduced to the general public in 1999 by Roger Schoer. On Geektimes it was
repeatedly described . In particular, it was said that the design of the engine is several elements, including an asymmetric resonator and a magnetron. The latter sends electromagnetic radiation to the resonator, provoking the appearance of standing electromagnetic waves. Due to the fact that the design is asymmetrical, the waves create a different pressure on the walls of the engine and give thrust.
Earlier it was claimed that the operation of the engine violates the law of conservation of momentum. Two years ago, NASA published the results of a research engine. Then the scientists found out that in case of summing up the electric power of 60 W the engine gives about 80 micronewton thrust. After such an authoritative organization published such results, very few people already wanted to argue with them, although up to this point a large number of scientists questioned the existence of traction.
Relatively recently, the Chinese, who said that EmDrive is working, joined the chorus of voices advocating a “new type of engine”. Thus, they confirmed the results of the experiments of their colleagues from NASA. It was even reported that scientists from China decided to test the engine in Earth orbit.
Now the engine decided to
explore the experts under the leadership of Martin Taymara of Dresden University. They used to measure engine thrusts with the help of a specialized installation, which was developed more than four years ago and has been continuously improved since. This is a kind of
torsional scales , which were invented at the end of the XVIII century, they were used to verify and measure the laws of Coulomb and Newton. However, if a thread was used in conventional torsion scales, then in the development of the Germans, sensitive torsion springs were installed to hold the camera with the engine. The displacement of the camera is measured using a laser interferometer.
The accuracy of the device is so high that it allows you to fix the thrust force of a few micronewtons. In order to ensure the purity of experiments, scientists decided to minimize the influence of factors that could give extra cravings. To do this, the engine was placed in an almost complete vacuum, installed a system for monitoring the microclimate of the installation and protected the engine from interference with additional screens.
Despite all the precautions taken, the engine continued to work, its thrust was about 4 micronewtons. This is even slightly larger than the results of several other experiments. But the problem is that the camera has been fixed and offset. The worst thing for the coherent theory of the “impossible engine” is that the thrust was maintained even if the electromagnetic oscillations inside were suppressed.
According to experts, all this is because there is no unrecorded thrust, and the problem is with external factors, albeit unobtrusive. One of the factors is the earth's magnetic field. It was already mentioned above that, despite the additional protection of the engine with screens, the traction still appeared. Therefore, it was
concluded that the impact as a manifestation of the magnetic field of the Earth.
In addition to the EmDrive, other engines were tested, including the Mach engine, which was proposed by James Woodward in 1990. Here, for work, the principle is used that the inertial mass of the body arises only due to the gravitational interaction with all the bodies of the Universe. The interaction changes in the event that separate parts of the body fluctuate, which makes it possible for the body mass to fluctuate. If you pick up the changes by setting a certain order, you can achieve traction. Traction turned out too small - something about 1.2 micronewton. But as it turned out, the magnitude of the thrust depended on the angle of rotation of the engine, which indicates the presence of external factors, as is the case with the EmDrive.
So far, the evidence of the "inoperability" of the engines are only indirect, but scientists are working to acquaint other colleagues with their work. Many scientists have previously expressed in relation to the work of EmDrive in the spirit that, despite the fact that the external factor that provides “extra” cravings, has not yet been found, the whole structure cannot violate the laws of physics. It is either an error or that unaccounted factor. Unicorns - do not exist, no matter how much we would like.