Physics of the impossible: Invisibility
I am sure that there is no such person here who would not watch the movie “Star Wars” or the Star Trek series or some other fiction. In this genre, technologies are used that are not yet open in the real world: a protective force field, laser swords, movement of an aircraft at a speed close to the speed of light, telepathy, invisibility, etc. And the creation of such technologies seems impossible, but is this true of physics?
If you like this article, I will try to write a few more articles about other fruits of the human imagination. The next topic will be: protective force field.
Since this article is the first, so I will allow myself to digress a little from the main topic and try to prove the relativity of the impossible. You really do not kick me for it. :) I tried very hard, I hope you enjoy it.
I apologize for the offtopic. How nice to write articles on Habré: so many smart people. Write on any topic and still there are people who understand you. Better yet, most of these people understand this area better than me. So it is not necessary to go to school to learn something new - you just need to read the comments. Thanks, Habrahabr;)
Some time ago, the hypothesis that a huge tectonic plate could burst and turn into two continents seemed simply ridiculous and ridiculous. Indeed, where to get such a force that can break a tall sandwich of granite, silicon and aluminum? But now we all know that tectonic plates are quite capable of it. Some time ago, the hypothesis that dinosaurs became extinct due to the fall of a huge meteorite 10 km across seemed ridiculous and completely unreal. However, physicists have proven that this is also quite possible. What was previously considered impossible is quite likely to become an established scientific fact. Here are some examples:
So does it make sense to say that it is impossible to teleport from one place to another? Or that it is impossible to build a spacecraft capable of carrying us many light years from Earth to the stars? I think no.
Are there any theories with which we can still create these "impossible" devices? Rather yes than no. Quantum physics , nanophysics and string theory are a list of theories that can develop into more powerful and unimaginable theories, thanks to which I can pull an apple or a handful of raspberries from someone else's site, while remaining unnoticed, because I will have an invisible costume.
')
Perhaps the most promising in terms of invisibility of recent advances is the exotic new material known as " metamaterial ." It's funny, but once the existence of such material was also considered impossible, since it contradicts the laws of Maxwell's optics. But in 2006 they invented this material and made the object invisible to microwave rays. What is so special about this invention? And the fact that he is able to create an environment for light in which light moves “faster than in a vacuum” (That is, the special arrangement of implants in this material would create the same effect, as if the light in this medium moves faster which, of course, is impossible). This means that all the rays of light passing through the metamaterial are deflected and the object behind this material becomes invisible. The figure in blue shows the metamaterial, an orange object and red rays of light. This is undoubtedly a huge breakthrough in this area, but there are still a huge number of obstacles:
In general, at the present time, the goal is quite clear: to create with the help of nanotechnology metamaterials that can bend not only microwaves, but also visible light. Already proposed several very promising approaches. One of the proposals is to use ready-made methods, that is, to borrow used technologies of the microelectronic industry for the production of metamaterials. The photolithography technology is at the heart of the miniaturization of computers; it also serves as the engine of the computer revolution. This technology allows engineers to place on the silicon substrate the size of a thumbnail hundreds of millions of tiny transistors.
By the way, the power of computers doubles every 18 months (This pattern is Moore's law). This is due to the fact that with the help of ultraviolet radiation, scientists “etch” more and more tiny components on silicon chips. This technology resembles the process by which stencilled patterns are applied to a colorful T-shirt.
Here are just a few possible uses:
Another way to make a person somewhat invisible is to photograph the view behind him and then project this image directly on the person’s clothing or on the screen in front of him. This process is called "Optical Disguise." They even created a raincoat covered with tiny reflective beads that work like a projection screen. What happens behind is filmed on a video camera. Then this image enters the video projector, which in turn projects it onto the cloak in front. It seems that the light penetrates a person (see photo on the left).
However, if they move a little to the right or to the left of the central normal to this cloak, then it will be seen that this is a hoax. Therefore, it is necessary to use holograms - this is a three-dimensional image created by lasers. However, this method also has its own problems in implementation. First: it is necessary to create a holographic camera capable of taking at least 30 images per second; the second is the storage and processing of this information; third: design the image so that it looks realistic.
There is another, much more cunning way to become invisible, as outlined by HG Wells in the novel The Invisible Man. This method is possible thanks to the fourth dimension. Can a person leave our three-dimensional universe and soar above it, being in the fourth dimension? There is only one small problem: the existence of other dimensions has not yet been proved :) And the journey to such a dimension required far more energy than we have at the moment. Of course, this method lies far beyond our current knowledge and capabilities.
Given the tremendous progress achieved on the path to invisibility, it is possible to count on the appearance of such devices in the next few decades, or at least at the end of the century.
Thanks for attention. I hope the article did not seem boring and incomprehensible to you.
Material used: Michio Kaku "The Physics of the Impossible" , Stephen Hawking "A Brief History of Time . "
Question. Please answer this question: “What invention do you dream of the most and why?” I, for example, really want some affordable soft robot that would pretend to the enemy in battle, as I enjoy martial arts, but a real person cannot always be found to practice with him.
If you like this article, I will try to write a few more articles about other fruits of the human imagination. The next topic will be: protective force field.
Since this article is the first, so I will allow myself to digress a little from the main topic and try to prove the relativity of the impossible. You really do not kick me for it. :) I tried very hard, I hope you enjoy it.
I apologize for the offtopic. How nice to write articles on Habré: so many smart people. Write on any topic and still there are people who understand you. Better yet, most of these people understand this area better than me. So it is not necessary to go to school to learn something new - you just need to read the comments. Thanks, Habrahabr;)
Impossibility is a relative concept
If at first the idea does not seem absurd, it is hopeless. © Albert Einstein
Some time ago, the hypothesis that a huge tectonic plate could burst and turn into two continents seemed simply ridiculous and ridiculous. Indeed, where to get such a force that can break a tall sandwich of granite, silicon and aluminum? But now we all know that tectonic plates are quite capable of it. Some time ago, the hypothesis that dinosaurs became extinct due to the fall of a huge meteorite 10 km across seemed ridiculous and completely unreal. However, physicists have proven that this is also quite possible. What was previously considered impossible is quite likely to become an established scientific fact. Here are some examples:
- Did you know that it was once proved that black holes cannot form naturally? And Einstein himself proved it. But he was wrong. Hubble telescope is easy to find similar phenomena of nature. By the way, black holes are areas of the universe with a very large density or with a very small volume. In general, there is a very large gravity in a black hole that even light cannot escape from it. If such geniuses are mistaken, why can we not be mistaken, saying that it is impossible to return to the past?
- At the end of the 19th century, scientists believed that the age of the Earth could not be several billion years. However, it was proved that the nuclear forces discovered by Madame Curie and other scientists are fully capable of keeping the Earth’s core in the molten state for billions of years due to radioactive decay. Wrong again.
- Previously, everyone believed that a rocket could not fly in space, because it has nothing to push off (there is no air). The first one of the leaders who believed in the existence of "space" rockets was Adolf Hitler. He forced his scientists to study this question better and as a result, the V-2 rocket was created, which became almost deadly for Britain. Here the error cost a lot of life.
- Even nobody believed in the existence of the atomic bomb, including Einstein. But nuclear physicist Leo Szilard just fantasized about this topic and thought of a chain reaction, after which he organized secret correspondence with Einstein and Franklin Roosevelt. The outcome was the Manhattan project, the creation of the atomic bomb, Hiroshima and Nagasaki, and the terrible cold war, and the collapse of the USSR. These are the consequences ...
So does it make sense to say that it is impossible to teleport from one place to another? Or that it is impossible to build a spacecraft capable of carrying us many light years from Earth to the stars? I think no.
Theories of the Future
Are there any theories with which we can still create these "impossible" devices? Rather yes than no. Quantum physics , nanophysics and string theory are a list of theories that can develop into more powerful and unimaginable theories, thanks to which I can pull an apple or a handful of raspberries from someone else's site, while remaining unnoticed, because I will have an invisible costume.
')
Invisibility
Metamaterials
Perhaps the most promising in terms of invisibility of recent advances is the exotic new material known as " metamaterial ." It's funny, but once the existence of such material was also considered impossible, since it contradicts the laws of Maxwell's optics. But in 2006 they invented this material and made the object invisible to microwave rays. What is so special about this invention? And the fact that he is able to create an environment for light in which light moves “faster than in a vacuum” (That is, the special arrangement of implants in this material would create the same effect, as if the light in this medium moves faster which, of course, is impossible). This means that all the rays of light passing through the metamaterial are deflected and the object behind this material becomes invisible. The figure in blue shows the metamaterial, an orange object and red rays of light. This is undoubtedly a huge breakthrough in this area, but there are still a huge number of obstacles:- The length of microwave rays is 3 cm. Therefore, in order for the metamaterial to reflect microwave rays, implants for this material must be less than 3 cm wide. But the wavelength of visible rays ranges from 400 to 700 nanometers, or from 0.00004 to 0.00007cm. That is, implants should be very, very small. Here, without nanotechnology can not do.
- To make an object completely invisible, you will need to create a metamaterial capable of bending light in three dimensions, and not only in flat two-dimensional surfaces. We'll have to somehow assemble the plane.
- So far, all metamaterials are capable of bending light of only one frequency, and it will be necessary to create such material that will work for the frequency band. Here, most likely you will have to create a multilayer material.
- But the shield of invisibility, even being finally created in the laboratory, may not be the way we want it. Most likely, it will be a heavy and unwieldy device. The Harry Potter cloak will be far away. And besides, it will be impossible to see something through this device if you are inside it. If you make holes for the eyes, then from the side will be observed flying eyes - scary :)
In general, at the present time, the goal is quite clear: to create with the help of nanotechnology metamaterials that can bend not only microwaves, but also visible light. Already proposed several very promising approaches. One of the proposals is to use ready-made methods, that is, to borrow used technologies of the microelectronic industry for the production of metamaterials. The photolithography technology is at the heart of the miniaturization of computers; it also serves as the engine of the computer revolution. This technology allows engineers to place on the silicon substrate the size of a thumbnail hundreds of millions of tiny transistors.
By the way, the power of computers doubles every 18 months (This pattern is Moore's law). This is due to the fact that with the help of ultraviolet radiation, scientists “etch” more and more tiny components on silicon chips. This technology resembles the process by which stencilled patterns are applied to a colorful T-shirt.
Other Metamaterial Applications
Here are just a few possible uses:
- They can lead to the creation of a flat super lens operating in the visible part of the spectrum. It will allow to obtain a higher resolution and distinguish parts that are much smaller than the length of the light wave.
- The ability to photograph microscopic objects with unprecedented clarity; it may even be about photographing a human cell or diagnosing fetal diseases in the womb.
- Photographing DNA molecules without X-ray
Holograms and invisibility
Another way to make a person somewhat invisible is to photograph the view behind him and then project this image directly on the person’s clothing or on the screen in front of him. This process is called "Optical Disguise." They even created a raincoat covered with tiny reflective beads that work like a projection screen. What happens behind is filmed on a video camera. Then this image enters the video projector, which in turn projects it onto the cloak in front. It seems that the light penetrates a person (see photo on the left).However, if they move a little to the right or to the left of the central normal to this cloak, then it will be seen that this is a hoax. Therefore, it is necessary to use holograms - this is a three-dimensional image created by lasers. However, this method also has its own problems in implementation. First: it is necessary to create a holographic camera capable of taking at least 30 images per second; the second is the storage and processing of this information; third: design the image so that it looks realistic.
Invisibility through the fourth dimension
There is another, much more cunning way to become invisible, as outlined by HG Wells in the novel The Invisible Man. This method is possible thanks to the fourth dimension. Can a person leave our three-dimensional universe and soar above it, being in the fourth dimension? There is only one small problem: the existence of other dimensions has not yet been proved :) And the journey to such a dimension required far more energy than we have at the moment. Of course, this method lies far beyond our current knowledge and capabilities.
Conclusion
Given the tremendous progress achieved on the path to invisibility, it is possible to count on the appearance of such devices in the next few decades, or at least at the end of the century.
Thanks for attention. I hope the article did not seem boring and incomprehensible to you.
Material used: Michio Kaku "The Physics of the Impossible" , Stephen Hawking "A Brief History of Time . "
Question. Please answer this question: “What invention do you dream of the most and why?” I, for example, really want some affordable soft robot that would pretend to the enemy in battle, as I enjoy martial arts, but a real person cannot always be found to practice with him.
Source: https://habr.com/ru/post/64672/
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