July 16, 2009 at 20:09Physics of the Impossible: Invisibility
I am sure that there will not be such a person who would not watch the movie "Star Wars" or the series "Star Trek" or any other fiction. This genre uses technologies that have not yet been discovered in the real world: a protective force field, laser swords, aircraft moving at a speed close to the speed of light, telepathy, invisibility, etc. And the creation of such technologies seems impossible, but is it so on the part of physics?
If you like this article, then I will try to write some more articles about other fruits of the human imagination. The next topic will be: a 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 don’t 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 have a better understanding of this area than I do. So you don’t have 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 know that tectonic plates are quite capable of this. Some time ago, the hypothesis that dinosaurs became extinct due to the fall of a huge meteorite of 10 km across seemed ridiculous and completely unrealistic. However, physicists have proved that this is also quite possible. What was previously considered impossible may well become an established scientific fact. Here are some examples:
So does it make sense to say that teleporting from one place to another is impossible? Or is it impossible to build a spaceship that can take 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 - here is a list of those theories that can grow into more powerful and unimaginable theories, thanks to which I can still pull an apple or a handful of raspberries from someone else’s site, while remaining unnoticed, because I will be invisible.
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 such an environment for light in which light moves “faster than in a vacuum” (That is, a special arrangement of implants in this material would create the same effect as if light in this medium moves faster, which, of course, is impossible). This means that all rays of light passing through the metamaterial are rejected and the object behind this material becomes invisible. The figure shows blue metamaterial, an orange object and red rays of light. This is undoubtedly a huge breakthrough in this area, but still there are a huge number of obstacles:
In general, at present, the goal is very clear: to create using nanotechnology metamaterials that can bend not only microwaves, but also visible light. Several very promising approaches have already been proposed. One of the proposals is to use ready-made methods, that is, to borrow from the microelectronic industry technologies that have been used for the production of metamaterials. At the heart of computer miniaturization is the Photolithography technology ; it also serves as the engine of the computer revolution. This technology allows engineers to place hundreds of millions of tiny transistors on a silicon substrate the size of a thumbnail.
By the way, the power of computers doubles every 18 months (This pattern is Moore's law). This is due to the fact that scientists using ultraviolet radiation "etch" increasingly tiny components on silicon chips. This technology is reminiscent of the process by which a pattern is printed on a colorful T-shirt.
Here are just a few possible uses:
Another way to make a person partially invisible is to photograph the view behind him and then project this image directly on the person’s clothes or on the screen in front of him. This process is called Optical Masking. They even created a cloak covered with tiny reflective beads that worked like a movie screen. What happens behind is filmed on a camcorder. Then this image enters the video projector, which in turn projects it onto the cloak in front. It seems that light penetrates a person. (See photo on the left).
However, if they move slightly to the right or left of the central normal to this cloak, 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 implementation problems. First: you need to create a holographic camera capable of taking at least 30 pictures per second; second: storage and processing of this information; third: designing an image so that it looks realistic.
There is another, much trickier way to become invisible, outlined by Herbert Wells in the novel The Invisible Man. This method is possible due 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 much more energy than we currently have. Of course, this method lies far beyond our current knowledge and capabilities.
Given the enormous successes achieved on the path to invisibility, it is entirely possible to count on the appearance of such devices in the next few decades or, at the very 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 “Physics of the impossible” , Stephen Hawking “A Brief History of Time” .
Question. Please answer this question: “What invention do you dream most of all and why?” For example, I really want some affordable soft robot that would simulate the enemy in battle, since I am fond of martial arts, and a real person can not always be found to practice with him.
If you like this article, then I will try to write some more articles about other fruits of the human imagination. The next topic will be: a 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 don’t 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 have a better understanding of this area than I do. So you don’t have to go to school to learn something new - you just need to read the comments. Thanks, Habrahabr;)
Impossibility is a relative concept
If at the first moment 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 know that tectonic plates are quite capable of this. Some time ago, the hypothesis that dinosaurs became extinct due to the fall of a huge meteorite of 10 km across seemed ridiculous and completely unrealistic. However, physicists have proved that this is also quite possible. What was previously considered impossible may well become an established scientific fact. Here are some examples:
- Do you know what was once proven that black holes cannot form naturally? Moreover, Einstein himself proved it . But he was wrong. The Hubble Telescope easily discovered similar natural phenomena. By the way, black holes are parts of the universe with a very high density or with a very small volume. In general, there is very large gravity in a black hole that even light cannot fly out of it. If such geniuses are mistaken, then why cannot we be mistaken in 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 quite capable of keeping the Earth's core in a molten state for billions of years due to radioactive decay. Wrong again.
- Previously, everyone believed that a rocket cannot fly in space, since it has nothing to push from (there is no air). The first who among the leaders believed in the existence of "space" rockets was Adolf Hitler. He forced his scientists to study this issue better and as a result the V-2 rocket was created , which became almost deadly for Britain. Here the mistake cost many lives.
- Nobody once believed even the existence of the atomic bomb, including Einstein. But nuclear physicist Leo Szilard simply fantasized on this subject and thought of a chain reaction, after which he organized a secret correspondence with Einstein and Franklin Roosevelt. The result was the Manhattan project, the creation of the atomic bomb, and Hiroshima from Nagasaki, and the terrible cold war, and the collapse of the USSR. These are the consequences ...
So does it make sense to say that teleporting from one place to another is impossible? Or is it impossible to build a spaceship that can take 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 - here is a list of those theories that can grow into more powerful and unimaginable theories, thanks to which I can still pull an apple or a handful of raspberries from someone else’s site, while remaining unnoticed, because I will be invisible.
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 such an environment for light in which light moves “faster than in a vacuum” (That is, a special arrangement of implants in this material would create the same effect as if light in this medium moves faster, which, of course, is impossible). This means that all rays of light passing through the metamaterial are rejected and the object behind this material becomes invisible. The figure shows blue metamaterial, an orange object and red rays of light. This is undoubtedly a huge breakthrough in this area, but still there are a huge number of obstacles:- The length of the microwave rays is 3cm. Therefore, in order for the metamaterial to reflect microwave rays, the implants of this material must be less than 3 cm wide. But the wavelength of visible rays is from 400 to 700 nanometers or from 0.00004 to 0.00007 cm. That is, the implants must be very, very small. Nanotechnology is indispensable here.
- To make the object completely invisible, it will be necessary to create a metamaterial capable of bending light in three dimensions, and not just in flat two-dimensional surfaces. Have to somehow compose 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 invisibility shield, even when finally created in the laboratory, may not be what we want. Most likely, it will be a heavy and clumsy device. Harry Potter’s 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 you will see flying eyes - scary :)
In general, at present, the goal is very clear: to create using nanotechnology metamaterials that can bend not only microwaves, but also visible light. Several very promising approaches have already been proposed. One of the proposals is to use ready-made methods, that is, to borrow from the microelectronic industry technologies that have been used for the production of metamaterials. At the heart of computer miniaturization is the Photolithography technology ; it also serves as the engine of the computer revolution. This technology allows engineers to place hundreds of millions of tiny transistors on a silicon substrate the size of a thumbnail.
By the way, the power of computers doubles every 18 months (This pattern is Moore's law). This is due to the fact that scientists using ultraviolet radiation "etch" increasingly tiny components on silicon chips. This technology is reminiscent of the process by which a pattern is printed on a colorful T-shirt.
Other uses of metamaterial
Here are just a few possible uses:
- They can lead to the creation of a flat super lens that works in the visible part of the spectrum. It will allow to obtain a higher resolution and distinguish between details that are significantly inferior in size to the length of the light wave.
- The ability to photograph microscopic objects with unprecedented clarity; we can even talk about photographing a human cell or diagnosing fetal diseases in the womb of the mother.
- X-ray photography of DNA molecules
Holograms and Invisibility
Another way to make a person partially invisible is to photograph the view behind him and then project this image directly on the person’s clothes or on the screen in front of him. This process is called Optical Masking. They even created a cloak covered with tiny reflective beads that worked like a movie screen. What happens behind is filmed on a camcorder. Then this image enters the video projector, which in turn projects it onto the cloak in front. It seems that light penetrates a person. (See photo on the left). However, if they move slightly to the right or left of the central normal to this cloak, 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 implementation problems. First: you need to create a holographic camera capable of taking at least 30 pictures per second; second: storage and processing of this information; third: designing an image so that it looks realistic.
Invisibility through the fourth dimension
There is another, much trickier way to become invisible, outlined by Herbert Wells in the novel The Invisible Man. This method is possible due 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 much more energy than we currently have. Of course, this method lies far beyond our current knowledge and capabilities.
Conclusion
Given the enormous successes achieved on the path to invisibility, it is entirely possible to count on the appearance of such devices in the next few decades or, at the very 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 “Physics of the impossible” , Stephen Hawking “A Brief History of Time” .
Question. Please answer this question: “What invention do you dream most of all and why?” For example, I really want some affordable soft robot that would simulate the enemy in battle, since I am fond of martial arts, and a real person can not always be found to practice with him.