What is EmDrive?
EmDrive is a propulsion system consisting of a magnetron and a resonator, which is not
Installation of EmDrive was first proposedBritish engineer Roger Scheuer in 1999. The magnetron used in it generates microwaves, the energy of their oscillations is accumulated in a high-Q resonator, and, according to the author, a standing wave of electromagnetic oscillations in a closed resonator of a special shape is a source of thrust.
Outside the resonator, not only matter is not emitted,but also electromagnetic radiation; in other words, EmDrive is not a photon drive. But even if the microwaves generated by the magnetron were completely emitted in one direction, the thrust obtained would be significantly less than the declared thrust of the EmDrive.
The absence of a consumable working fluid for thisengine, obviously violates the law of conservation of momentum, and the authors of the developments have not proposed any generally accepted explanation for this contradiction - Scheuer himself published a non-peer-reviewed work with an explanation, but physicists note that the theory of radiation pressure is more complex than the simplified apparatus used by Scheuer, and his explanations are generally contradictory.
Experimental data were not provided for a long timeunambiguous confirmation or refutation of the operability of such an installation, which was also due to the small magnitude of the expected effect, comparable to measurement errors.
Physicists explained what experimenters foundfew positive results due to errors in experiments. The only independent study published in a scientific journal that showed a positive result was an experiment by the groupEagleworks2016, which eliminated many sources of possible errors.
However, the work of a research group from the Dresden University of Technology showed that the measured "thrust" EmDrive arises from the influence of external factors, and not because of the device itself.
Experimental tests
- Plant manufacturers
EmDrive was first introduced by British aerospace engineer Roger Scheuer in 1999. In December 2002, the company founded by ScheuerSatellite Propulsion Researchthe first supposedly working prototype was presented, developing a force of 0.02 N.
In October 2006, the same company showed a prototype with a declared thrust force of 0.1 N. In 2015, another version of the EMDrive with a superconducting cavity was presented.
In the period 2006-2011. American companyCannae LLCunder the leadership of Guido Fetta, the “Cannae Drive” (also known as “Q-drive”) was created - an engine for which a similar operating principle was declared.
- Yang Juan's group
In the period 2008-2010.at the Chinese Northwestern Polytechnic University, under the leadership of Professor Yang Juan, a prototype was created that allegedly developed an effort of 0.72 N. measurement noise limits.
- Harold White's group
Since 2013, the Cannae Drive engine has been tested in the laboratoryEagleworks. This laboratory works in the space centerJohnson under the auspices of NASA with a relatively small budget of 50 thousand dollars a year and specializes in the study of technologies that contradict generally accepted scientific ideas.
The work was carried out under the direction of HaroldWhite. White believed that such a resonator could work by creating a virtual plasma toroid that implements thrust using magnetohydrodynamics for quantum vacuum oscillations.
During experiments in 2013-2014, it was obtainedthe anomalous result is a thrust of about 0.0001 N. The test was carried out on a small force torsion pendulum, which is capable of detecting forces of tens of micronewtons, in a stainless steel vacuum chamber at room temperature and normal atmospheric pressure.
The resonator tests were carried out at a verylow power (50 times less than in Scheuer's experiment in 2002), but the net thrust for five launches was 91.2 μN with an input power of 17 W. The short-term maximum thrust was 116 μN at the same power.
Publication of workEagleworkshas led to EmDrive being sometimes described as "NASA-tested", although the agency's official position is that "it is a small project that has not yet led to practical results."
In November 2016, the work was published,carried out by engineers of the NASA Eagleworks laboratory, in which many sources of possible errors were taken into account and eliminated, the EmDrive thrust was measured and a conclusion was made about the operability of this installation.
According to this article, the engine was able to develop thrustin 1.2 ± 0.1 mN / kW in vacuum with powers of 40, 60 and 80 W. The article suggests that engine performance can be explained using pilot wave theory.
- Martin Taimar's group from Dresden University of Technology
In July 2015, tests were carried out under the direction of Martin Taimar at the Technical University of Dresden. The results did not confirm, but did not disprove the functionality of EmDriver.
New results published in 2018the group of Martin Taimar, according to which the thrust observed in the experiments with EmDrive (including, apparently, the experiments of the Eagleworks group), is rather associated with insufficient shielding of the installation from the Earth's magnetic field than with the propulsion system itself: measurements showed the presence of a small thrust in one and the same direction even when the orientation of the installation is changed or the electromagnetic waves entering the cavity are suppressed.
Further tests of the Taimar group finally showed that EmDrive does not create traction.
- Alleged Chinese space tests
In December 2016, citingpress conference of one of the subsidiaries of the Chinese Academy of Space Technology (CAST), the International Business Times reported that the Chinese government has been funding engine research since 2010, and EmDrive prototypes were sent into space for testing on board the Tiangong-2 space laboratory "
Dr. Chen Yue (Chen yue) from CAST, according to publicationInternational Business Times, confirmed the fact that a prototype engine was manufactured for testing in low Earth orbit.
In September 2017, new reports emerged of the successful creation of a working prototype of the EmDrive engine in China.
- Plymouth University
In 2018, DARPA awarded Plymouththe university $1.3 million to study and create a “fuelless engine” based on “quantized inertia” (Mike McCulloch’s alternative cosmological hypothesis, contradicting the special and general theories of relativity). Some media outlets report a connection between the project and the ideas of EmDrive.
How does EmDrive work?
This device, operating on the basis of microwave radiation, is a special conical resonator chamber to which a powerful magnetron is connected - a source of microwave radiation.
With a certain geometry of this cone, this device will mysteriously move towards its narrow part with extremely small, but force, if microwaves “walk” inside the cone.
British aircraft engineer RogerScheuer abandoned his idea, and a few years later it was tested by a number of professional physicists, including one of NASA laboratories. These tests, writes Michael McCulloch from the University of Plymouth (UK), led to unexpected results for scientists - it turned out that Scheuer's invention really works.
McCulloch offered a physically plausible explanation for this “miracle engine,” drawing attention to another controversial thing—the so-called Unruh effect.
This phenomenon was discovered by the American physicist William Unruh in the late 70s of the last century and it represents an explanation of why the force of inertia exists.
Unruh showed that an object moving withacceleration, begins to interact in a special way with the vacuum or other medium through which it moves - to put it simply, the surrounding space becomes «warmer» for him. This heat “presses” on the moving body and causes it to slow down.
Criticism
The scientific community for the most part does notbelieved in the test results of the controversial engine. Mark Mills, who headed the now-defunct Breakthrough Propulsion Physics lab, believes that the anomalous thrust could have resulted from the interaction of the engine with the test chamber.
Mills' laboratory at one time was engaged intasks similar to Eagleworks, that is, testing various semi-fictional space engine projects. So he has enough experience to make such assumptions.
Rochester Institute of Technology astrophysicist and Forbes science columnist Brian Coberlein noted that publishing an article in a peer-reviewed journal does not mean that the result will be correct.
Russian scientists also criticized the ideaEmDrive. Astrophysicist, editor-in-chief of the Troitsky Variant newspaper and member of the RAS Commission for Combating Pseudoscience Boris Stern called the very possibility of creating an impossible engine nonsense.
Similar experiments
- Rossi Energy Catalyst
In 2009, an application was filed for the alleged invention of “method and apparatus for carrying out an exothermic reaction between nickel and hydrogen, releasing copper.”
The patent refers to previous work oncold nuclear fusion, although, according to one of Rossi's statements, this is not cold nuclear fusion, but rather a low-energy nuclear reaction. A similar system, but producing less energy, was previously described by Fokardi et al.
Although the Italian patent, as well as internationalpatent applications describe the structure and general operation of the device, the detailed operation of the device is a trade secret, and the device is viewed by an independent party as an opaque black box. Observers measured the input and output energy at various times during the public demonstration. Widom and Larsen proposed a theory as an explanation for elemental transformation and the release of excess energy.
Rossi and Focardi's joint paper on "cold fusion" was rejected by a peer-reviewed scientific journal and appeared on Rossi's self-published blog.
To publish their results, Rossi and Focardi founded their own online blog in 2010, calling itJournal of Nuclear Physics (the name of the blog is similar to the name of some scientific journals). Focardi's closely related work was published in 1998 in the peer-reviewed scientific journal Il Nuovo Cimento A.
- Bubble Alcubierre
This is an idea based on solving Einstein's equations, proposed by Mexican theoretical physicist Miguel Alcubierre, in which a spacecraft could reach superluminal speed.
Moving above the speed of light is impossible forobjects with real non-zero mass in normal space-time. However, instead of moving above the speed of light within the local coordinate system, the spacecraft can move, compressing space in front of it and expanding it behind, which allows it to virtually travel at any speed, including faster than light.
In 2012, the Eagleworks group, led byHarold White, announced the creation of the White-Juday interferometer, which they claim can detect spatial disturbances created by strong electric fields. The experiment is described in detail in the work of Harold WhiteWarp Field Mechanics 101.
- Energy from the air
Valery Maisotsenko, Doctor of Technical Sciences,Professor, author of about 200 scientific and technical papers and three dozen topical breakthrough patents, found a way to extract energy from the air through natural, environmentally friendly processes of air humidification, evaporation and condensation of water.
The Maisotsenko thermodynamic cycle is based onthe action of known physical laws. The space where moist, cooled air forms is an area of low pressure. Warm, dry air is in an area of high pressure.
Air always moves from an area of highpressure to low. As long as the air layers differ in temperature, humidity, pressure, there is a directional wind. And it blows the stronger, the greater the difference between the initial parameters.
After 30 years, his developments are used byall over the world. A water-based evaporative-condensing heat pump is now capable of replacing district heating and compression climate technology, and the M-cycle may in the future implement a fundamentally new thermodynamic concept for engines and turbines.
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