For every action, there is an equal and opposite action. This formulation of Newton's third law has two very important consequences: first, there is a physical quantity that is always preserved in the universe (momentum), and secondly, the laws of physics are the same regardless of your position in space. It would seem that only a few words, but in fact they are colossal, because if you want to force, for example, a device to change movement, you need to push it with something.
This could be rocket exhaust, tires against the road, train wheels on rails, or even photons bouncing off a sail. The only thing that is prohibited is the so-called inercoid, motion without reaction: action without reaction. This is what EMDrive - an "impossible" space engine that recently passed NASA tests - is said to be. If it actually works as advertised, it is breaking the laws of physics. But there is also a possible loophole: perhaps there is a reaction, we just did not find it. It is possible that there is opposition, but it is associated with dark matter.
According to the standard model of cosmology, most of the matter in the universe is not in the form of atoms or other known particles. No, the vast majority of mass - within 5-to-1 difference - is dark matter. Dark matter does not collide, does not annihilate, and no longer interacts with itself or with other, ordinary matter under any known circumstances, except for gravitational influence. 13.8 billion years later, it has formed a giant, diffuse cosmic network of gravitational structures and huge spherical halos over a million light-years in diameter that flank galaxies like ours. Dark matter permeates every square centimeter of our galaxy, including every object on Earth, even our bodies, albeit in small quantities.
Under certain conditions, however, dark matter can be persuaded to interact with itself or with ordinary matter, depending on its nature. If dark matter consists of WIMPs (WIMP, a weakly interacting massive particle), then the product of its annihilation could be detected by detectors. If it consists of very light, low-mass particles of axions, it can combine with photons under certain conditions. One of the experiments aimed at finding axions is known as ADMX: the dark matter axion experiment. In 1983, physicist Pierre Sikivi invented the axion haloscope, exploiting the fact that an axion-photon pair can be amplified under certain conditions within an electromagnetic cavity. Twenty years later, ADMX grew out of this study and since then scientists have been looking for axions using this method.
To date, unfortunately, their search has not yet been crowned with success. Perhaps axions do not exist, or, if they are not dark matter, they may have different parameters for which ADMX is not sensitive enough. It is quite possible that different electromagnetic cavities with different properties could activate interactions with axions. Possibly, photon-axion interactions can occur, and the cavity with the required parameters led to the scattering of axions in the preferred direction. It is unlikely, but quite acceptable, that EMDrive is such a cavity.
How it works? At any given moment in time, dark matter particles pass through all areas of space, without being constrained by the presence of matter or other particles of the Standard Model. In the electromagnetic cavity, photons of a certain frequency jump in all directions, maintaining momentum and not creating thrust. But if the photons move in a certain direction - for example, to the back of the cavity - they can collide with dark matter particles and this will be:
Promotional video:
- The photon changes momentum and moves "a little less backward" and "a little more forward" than it was before the collision with the dark matter particle.
- The photon collides with the cavity wall, bounces off it, and transmits an impulse forward to the cavity itself.
- A particle of dark matter receives an impulse in just the opposite direction: back.
- The momentum is preserved because the dark matter carries it away, equal and opposite in magnitude to that which absorbs the cavity.
If this is what happens, then this is a real breakthrough. Since dark matter is everywhere, we would only need a source of energy - not fuel - to travel across the galaxy, because at any point in space we will find enough dark matter. This means that we will receive a method for detecting dark matter that accidentally collides with our particles, and thus confirm its existence. And most importantly, all this does not violate the laws of physics, because the momentum is preserved.
The EMDrive test results have yet to be proven. There are many potential sources of error, and the measurements themselves indicate a large uncertainty in how much thrust is produced. It is not yet clear whether there really is a thrust without reaction, or whether there is a reaction that we have not yet found.
And the explanation involving dark matter will also be dubious, since it requires many unknowns. But if EMDrive really works using dark energy, and the mystery of dark matter is solved once and for all in the most unexpected way, it will be incredible.
ILYA KHEL
