The theory of absolute invisibility or Thoughts on the invisible cap

Many scientists are able to sell "air" - not yet done work. But to ensure that you have been allocated money for work, the result of which is impossible to see by definition - this, in my opinion, is the pinnacle of fundraising. Nevertheless, I was lucky to meet with one such scientific work.

When you ask scientists if they know how to sell "air", many people look at you like an idiot. Indeed, these are clever people who are engaged in highly intellectual activity and all that. However, it is the air they often trade. At least, this is how the grant system of financing science is built: the scientist promises to do something, he is given money for it, and only then he gets to work.

Strange as it may sound for some scientists, but the result of scientific activity is not an article in a scientific journal, nor a speech at a conference. It is rather a method of fixing or even popularizing the result. Therefore, it was very interesting for me to get acquainted with the group, the result of whose work (more precisely, its practical implementation) cannot be seen by definition.

The head of this research group, Alexey Basharin, became my test task when applying for a job at NITU “MISiS”. Official information about the work of Alexei can be found on the university website. Here I can only say that this was my first detailed acquaintance with metamaterials. These are such strange substances, whose properties depend not so much on the set of atoms from which they are made, but on the structure. For a while, I, a certified chemist from Moscow State University, had to spend on putting this concept in my head. Although, I must say, I had to face the prerequisites for the existence of metamaterials even in the course of my own scientific activities.

But if the nanoparticles of metals in an inert matrix behaved at least somewhat similar to their larger or smaller counterparts, then something unimaginable is happening with the metamaterials. Literally do not understand what you can almost saw with a jigsaw a lot of structures that do not fundamentally resemble each other in their properties. If you want - there will be an invisible material for you, if you want - an atom the size of a five-story house.

However, jigsaw saw a five-story building for a long time. And with invisibility, not everything is in order. First, there are not so many transparent substances in the world. Secondly, there are not so many ways to make an object invisible or even simply indistinguishable. The most obvious is when the refractive indices of the transparent object and the transparent medium coincide. The second is more suitable for opaque objects - when its color coincides with the background color (from the point of view of the observer). Although, invisibility in this case is rather conditional - technically we see the object, we simply do not perceive it.

The third method works only in a very narrow frequency range - the surface of the body absorbs or scatters the waves of this particular frequency (consider that it reflects anywhere, and not in the direction from which the scanning beam came). This is how STEALTH technologies work. With their help, the size of giant bombers on the radar screen is compressed to the size of a large bird. But this effect can be achieved only in the centimeter and decimeter ranges. In meter, no matter how you change the geometry of the object, no matter how structured the surface, nothing happens - too long waves compared to the length of the object. And in general, at the existing level of technology, it is impossible to make an object completely invisible even in the radio band.

As the experimental development continues, the information field periodically explodes with messages about the “invisible cap”, then about the “invisibility cloak”, or about some other piece of clothing. In actual fact, of course, it turns out that this cap has a diameter of 4 microns and is only half invisible, the raincoats are collected from mobile phones, and the video produced in China in recent days is generally montage. My eldest daughter can do even better.

In general, the problem we have with the creation of invisible objects. I would like to believe that we are theoretically well-grounded, but even here there are problems. Of course, scientists tried to invent the invisibility mathematical apparatus more than once. But even with theoretically studied objects, even having dimensions much larger than the length of the wave that runs around them, it is impossible to achieve complete invisibility. As Aleksey explained, this is why they, together with colleagues from the Polytechnic University of Turin, did work on the theory of absolute invisibility. Taking into account new research in the field of metamaterials, theorists have a chance to "catch the invisibility by the tail."

It was here that the very work arose, the practical embodiment of which is impossible to see - the ANASTASIA project (Advanced Non-radiating Architectural Scattering Tenuously And Sustaining Invisible Anapoles). If physicists can make their plans, the result will be an absolutely invisible object. According to Alexey, they “have an idea” how to do it. And the right thought can bend anything into the ram's horn. Even a ray of light.


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