"Raise shields!" - is the first order, which in the endless series "Star trek" gives a sharp voice captain kirk its crew; obey the orders of the crew includes force field, designed to protect the space ship "enterprise" from enemy fire.

In the story "Star trek" force fields are so important that their condition might well determine the outcome of the battle. Is the energy force fields are depleted, the body "enterprise will receive blows, the further, the deeper; in the end, defeat is inevitable.

So what is a protective force field? In science fiction it is deceptively simple thing: thin invisible, but impenetrable barrier capable equally easy to reflect laser beams and missiles. At first glance, the force field appears so simple that creation - and soon - fighting boards based on it seems inevitable. And expect not today or tomorrow some enterprising inventor will announce that he was able to obtain a protective force field. But the truth is much more complicated.

Like a light bulb Edison, who revolutionized modern civilization, the force field is able to deeply affect all our lives. The military used force field to become invulnerable, would create on its basis an impenetrable shield against enemy missiles and bullets. In theory you could create bridges, splendid highway and the road one click of a button. Entire cities would arise in the desert as if by magic; all of them, until skyscrapers, would be built entirely of force fields. Dome force fields over cities would enable their inhabitants to freely manage weather events - storms, blizzards, tornadoes. Under reliable gentle force field could build cities, even on the bottom of oceans. From glass, steel and concrete could refuse, replacing all construction materials force fields.

But, strangely enough, the force field is one of those phenomena that are extremely difficult to reproduce in the laboratory. Some physicists believe that this could not be done without changing its properties.
Michael Faraday

The concept of physical fields originated in the work of the great British scientist of the XIX century, Michael Faraday.

Parents Faraday belonged to the working class (his father was a blacksmith). He is in the early 1800s, it was to apprentices at the binder and dragged out a pitiful existence. But the young Faraday was fascinated recent huge advance in science is the discovery of the mysterious properties of two new forces of electricity and magnetism. He greedily devoured all available information on these issues and attended the lectures of Professor Humphrey Davy of the Royal institution in London.

One day Professor Davey seriously damaged the eyes during an unsuccessful chemical experiment; it took the Secretary, and he took on the post of Faraday. Gradually the young man had gained the confidence of the scientists of the Royal institution and had the opportunity to conduct its own important experiments, though often he had to endure and neglect. Over the years, Professor Davey all revnivui belonged to the success of his talented young assistant, who first considered in circles experimenters rising star, and eventually eclipsed the glory of the Devi. Only after the death of Davy in 1829 Faraday received scientific freedom and carried out a whole series of remarkable discoveries. The result was the creation of electric generators, provided by the energy of the whole city and changed the course of world civilization.

The key to the greatest discoveries Faraday became law enforcement or physical fields. If you put the iron filings over the magnet and shake, you find that sawdust fit into the pattern resembling the web and taking all the space around the magnet. "Threads of a spider's web" - this is furadeeva power lines. They clearly show the distribution in space of the electric and magnetic fields. For example, if you draw the graph of the magnetic field of the Earth, you will find that line come from somewhere in the North pole area, and then come back and go again to the land in the area of the South pole. Similarly, if you draw the lines of force of the electric field lightning during a thunderstorm, you find that they agree on the tip of lightning.

Empty space for Faraday was not empty; it is filled by power lines, by which it was possible to get far move.

(Poor youth did not allow him to receive systematic education, and it is practically not versed in mathematics; consequently, his notebooks were filled not by the equations and formulas, and hand-drawn diagrams of power lines. Ironically, it is the lack of mathematical education led him to develop a great chart of power lines, which can be seen today in any textbook on physics. Physical picture in science often more important than the mathematical apparatus, which is used to describe it.)

Historians have put forward a lot of assumptions about what led him to the discovery of physical fields - one of the most important concepts in the history of world science. Virtually all of modern physics is written in the language furadeeva fields. In 1831 Faraday made a crucial breakthrough in the field of physical fields forever change our civilization. One day, carrying a magnet - children's toy over the wire frame, he noticed that in the frame occurs electric current, while the magnet is not in contact with it. This meant that the invisible field magnet able distance to force electrons to move, creating a current.

Force field Faraday, who up to this point was considered useless pictures, fruit pleasant, idle fantasy was real material force that can move objects and to generate energy. Today we can say for sure: the light source you are using to read this page, gets energy by Faraday's discoveries in the field of electromagnetism. Rotating magnet creates a field that pushes the electrons in a conductor and makes them move, giving rise to an electric current, which can then be used to power light bulbs. Based on this principle, the electricity generators that provide energy cities around the world. For example, a stream of water falling from the dam, causes the rotating giant magnet in the turbine; magnet pushes the electrons in the wire, forming an electric current; current, in turn, flows through the high-voltage wires in our homes.

In other words, force fields Michael Faraday, are the very forces that move modern civilization, in all its kinds - from electric locomotives to the latest computer systems, the Internet and handheld computers.

A century and a half furadeeva physical fields inspired physicists for further research. On Einstein, for example, they had such a strong effect that he formulated his theory of gravitation in the language of physical fields. At me too the work of Faraday has made the strongest impression. Several years ago I successfully made a string theory in terms of physical fields Faraday, thus laying the Foundation for the field of string theory. In physics to say about somebody that he thinks lines of force is to make this person a serious compliment.
Four fundamental interactions

One of the greatest achievements of physics over the past two millennia has been the selection and definition of the four types of interaction that rule the universe. All of them can be described in the language field, which we are obliged to Faraday. Unfortunately, however, none of the four species does not possess properties of fields is described in the most fantastic works. We list these types of interactions.

1. Gravitation. Silent force, which does not allow our feet to break away from the bearing. It is not disintegrating the Earth and the stars, helps maintain the integrity of the Solar system and Galaxy. Without gravity rotation of the planet'd have thrown us from the Earth into space at a speed of 1000 miles per hour. The problem is that the properties of gravity exactly the opposite properties fantastic force fields. Gravity is the force of attraction, not repulsive; she is extremely weak - relatively, of course; it works on a vast astronomical distances. In other words, is an almost complete contrast to the flat, thin, impermeable barrier, which can be found in almost any fantasy novel or movie. For example, a feather to the floor attracts the whole planet Earth, but we can easily overcome the pull of the Earth and to raise a feather one finger. The influence of one of our fingers are able to overcome the force of gravity of a planet, which weighs more than six trillion kilograms.

2. Electromagnetics (EM). The power of covering our cities. Lasers, radio, TV, modern electronics, computers, Internet, electricity, magnetism - all these are consequences of the manifestation of the electromagnetic interaction. This is perhaps the most useful power that managed to control mankind throughout its history. Unlike gravity it might work on the attraction and repulsion. However, it is not suitable for the role of a force field for severalHolcim reasons. First, it can be easily neutralized. For example, plastic or any other non-conductive material can easily penetrate into powerful electric or magnetic field. Piece of plastic, thrown in a magnetic field, freely pass through him. Secondly, electromagnetism is valid at large distances, its hard to focus in the plane. The laws of EM interactions are described by the equations of James Clerk Maxwell, and it looks like force fields are not the solution of these equations.

3 and 4. The strong and weak nuclear interaction. The weak interaction is the power of radioactive decay, the one that heats the radioactive core of the Earth. This force behind volcanic eruptions, earthquakes and drift continental plates. Strong interaction is not disintegrating the nuclei of atoms; it provides the energy of the sun and stars and is responsible for the lighting of the Universe. The problem is that the nuclear interaction works only on very small distances, mostly within the atomic nucleus. It is so strongly associated with characteristics of the kernel that manage extremely difficult. At present we know only two ways to influence this interaction: we can break subatomic particle in the accelerator or to explode a nuclear bomb.

Although the protective field in science fiction and not subject to known laws of physics, there are still loopholes that in the future, probably, will create force fields possible. First, there is, perhaps, the fifth type of fundamental interaction that anyone still failed to see in the laboratory. May be, for example, that this interaction works only at distances from a few inches to a foot - and not at astronomical distances. (However, the first attempts to detect the fifth type of interaction gave negative results.)

Second, we may be able to cause the plasma to mimic some properties of the force field. Plasma is the "fourth state of matter". The first three, familiar to us state of matter - solid, liquid and gaseous; however, the most common form of matter in the universe is in the plasma: gas, consisting of ionized atoms. The atoms in plasma is not linked and stripped of electrons, and therefore carry a charge. They can easily be controlled by electric and magnetic fields.

Visible matter of the universe exists mostly in the form of various kinds of plasma; it formed the sun, stars and interstellar gas. In ordinary life we almost do not face plasma, because on Earth, this phenomenon is rare; however, the plasma can be seen. It is enough to look at the lightning, the sun or plasma screen television.
Plasma window

As noted above, if you heat the gas to a temperature high enough and thus receive the plasma, using magnetic and electric fields will be possible to preserve it and to give it form. For example, the plasma can be given the shape of a leaf or window glass. Moreover, this "plasma" window you can use as a partition between the vacuum and the ordinary air. In principle, this way you could keep the air inside the spaceship, not allowing it to evaporate into space plasma in this case forms a convenient transparent membrane, the border between the open space of the ship.

In the TV series "Star trek" force field is used, in particular, in order to isolate the compartment where and from where starts a small space Shuttle, from outer space. And this is not simply a cunning trick, designed to save money on decorations; so transparent invisible film can be created.

Plasma box was invented in 1995 physicist Edie Hershkowitz at the Brookhaven national laboratory (long island, new York). This was developed in the process of solution of another problem - the problem welding of metals by means of electronic beam. Acetylene burner welder melts the metal flow of hot gas, and then connects pieces of metal together. It is known that the electron beam is able to weld metals faster, cleaner and cheaper than obtained by conventional methods of welding. The main problem of the method of electronic welding is that should be carried out in a vacuum. This requirement causes a lot of inconveniences, because it means the construction of the vacuum vessel size, possibly with an entire room.

To solve this problem, Dr herskowitz invented plasma window. This device is only 3 feet in height and 1 foot in diameter; it heats the gas to a temperature of 6500 C and thereby creates a plasma, which immediately falls into the trap of electric and magnetic fields. The plasma particles as particles of any gas pressure, which prevents air to rush in and fill the vacuum chamber. (To use in plasma window argon, it emits a bluish glow just like a force field in Star trek.)

Plasma window, obviously, will find wide application in space industry, and industry. Even in industry for micromachining and dry etching is often needed vacuum, but its application in the production process can be very expensive. But now, with the invention of plasma window, to keep the vacuum one click will be easy and inexpensive.

But is it possible to use a plasma window as impenetrable shield? Protects whether it shot out of a cannon? You can imagine the emergence in the future plasma Windows, with a much higher energy and temperature, sufficient to evaporate entering into it of interest. But to create more realistic force field with known by the fantastic works characteristics will require a multi-layered combination of several technologies. Perhaps each layer itself will not be strong enough to stop Cannonball, but together multiple layers may be enough.

Let's try to imagine the structure of such a force field. The outer layer, for example, sverhzaryadnogo plasma window, heated to a temperature sufficient for evaporation of metals. The second layer can be hung from the high-energy laser beams. This veil of thousands crossed laser beams would spatial lattice, which was heated, would pass through objects and effectively evaporated. In more detail, we will talk about the lasers in the next Chapter.

Further, for laser veil, you can imagine spatial lattice of carbon nanotubes" - tiny tubes consisting of individual carbon atoms, with the walls with one atom thick. This tube is many times stronger than steel. Currently the longest received in the world of carbon nanotubes has a length of only about 15 mm, but we can foresee a day when we will be able to create carbon nanotubes arbitrary length. Assume that carbon nanotubes can be woven spatial network; in this case we get extremely durable screen, capable to reflect most of the objects. This screen will be invisible, because each individual nanotube thickness is comparable to the atom, but the spatial network of carbon nanotubes surpasses the strength of any other material.

So, we have reason to believe that the combination of plasma window, laser veil and screen from carbon nanotubes could serve as a basis for creation of almost impenetrable, invisible wall.

But even such a multi-layered shield will not be able to demonstrate all the properties that science fiction assigns force field. So, it will be clear, and therefore will not be able to stop a laser ray. In the battle with laser cannons our multilayer boards will be useless.

To stop the laser beam, the shield must be in addition to possess a strong property of fotochromatyczne", or variable transparency. At present, the materials with such characteristics are used in the manufacture of sunglasses that can darken when exposed to UV radiation. Variable transparency of the material is achieved through the use of molecules that can exist in at least two States. When one state molecules such material is transparent. But under the influence of UV-radiation of molecules instantly move to another state and the material loses its transparency.

Maybe someday we will be able using nanotechnology to obtain the substance, solid as carbon nanotubes, and able to change their optical properties under the influence of the laser beam. Shield of such substances will be able to stop a flow of particles or shells, but the laser shot. Currently, however, there are no materials with variable transparency, capable to stop a laser ray.
Magnetic levitation

In science fiction force fields have another function, except reflect the impacts of the radiation weapons, namely to provide support, which allows to overcome the force of gravity. In the movie "Back to the future" Michael Fox goes on "hoverboard", or "floating Board"; this thing around resembles the skateboard, that's just "goes in the air above the earth's surface. The physical laws as we know them today - do not allow to realize like antigravity device (as we will see in Chapter 10). But you can imagine in the future the creation of other devices - soaring boards and soaring hire magnetic levitation; these machines will make it easy for us to raise and support the weight of large objects. In the future, if "superconductivity at a room temperature" will become an affordable reality, a person is able to levitate objects, using the possibilities of magnetic fields.

If we can pack the North pole permanent magnet to SevernWMD same pole of another magnet magnets will repel each other. (If we will turn one of magnets and give it to the South pole to the North pole to another, two magnets are attracted.) The same principle is that like poles of magnets repel each other, can be used for lifting from the earth, huge weights. Already in several countries is the construction of technically advanced Maglev trains. These trains carried not in the ways, and above them at a minimum distance; the weight of their retain conventional magnets. The train as if floating in the air and thanks zero friction to develop a record speed.

The world's first commercial automated transport system Maglev was started in 1984 in the British city of Birmingham. It connected the terminal of the international airport and situated close to the railway station. The Maglev trains are also in Germany, Japan and Korea, although most of them are not designed for high speeds. The first high-speed commercial Maglev train began to go running in the action part of the track in Shanghai; this train is moving along the road with a speed up to 431 km/H. the Japanese Maglev train in the Prefecture of Yamanashi accelerated to a speed of 581 km/h - that is moving much faster than conventional trains on wheels.

But the devices on magnetic suspension extremely expensive. One of the ways to increase their effectiveness is the use of superconductors that when cooled to temperatures close to absolute zero, completely lose their electrical resistance. The phenomenon of superconductivity was discovered in 1911 Heike kamerlingh-Onnes. Its essence was that some substances when cooled to a temperature below 20 K (20 C above absolute zero) lose all electrical resistance. As a rule, cooling of the metal its electrical resistance is gradually decreasing. {The fact that the directed motion of electrons in a conductor prevent random oscillations of atoms. With decreasing temperature scale random oscillations decreases, and electricity feels less resistance.) But kamerlingh-Onnes, to his amazement, he discovered that the resistance of certain materials at a certain critical temperature drops sharply to zero.

Physics immediately understood the importance of the result. During transmission over large distances in power lines lost a significant amount of electricity. But if resistance is resolved, electricity could be transferred to any place almost nothing. In General, excited in the closed loop of electrical current could circulate it without energy losses millions of years. Moreover, of these extraordinary currents easy it would be to create magnets incredible power. And with these magnets, it would be possible without efforts to raise huge cargo.

Despite excellent opportunities superconductors, apply them very difficult. Keep large magnets in tanks with extremely cold liquids very expensive. To save fluid is cold, will require a huge factory of cold, which will raise the cost of superconducting magnets to dizzying heights and make use of them unprofitable.

But once physicists, you may be able to create a substance that will keep superconducting properties even when heated to room temperature. Superconductivity at a room temperature - the "Holy Grail" physicists tverdohlebov. The receipt of such substances, in all probability, will serve as the beginning of the second industrial revolution. Powerful magnetic field, are able to support the weight of cars and trains, will be so cheap that even planning to hire", it may be economically advantageous. It may well be that with the invention of the super-conductors, retains its properties at room temperature, fantastic flying machines that we see in the film "Back to the future", "Special opinion" and "Star wars", will become a reality.

In principle it before we put that person will be able to wear a special belt of superconducting magnets, which allows him freely to levitate above the ground. With such a zone could fly through the air like Superman. In General, superconductivity at a room temperature the phenomenon is so great that the invention and use of such superconductors are described in many science fiction novels (such as the series of novels about World-Ring created by Larry Niven in 1970).

Decades of physics unsuccessfully sought substances that would have superconductivity at a room temperature. It was a tedious boring process is sought by trial and error, testing one material for another. But in 1986 opened a new class of substances called "high-temperature superconductors"; these substances are found superconductivity at temperatures of about 90 C above absolute zero, or 90 K. This discovery became a real sensation in the world of physics. It seemed that opened the gates of the gateway. Month after month physics competed with each other, trying to set a new world record of superconductivity. Some time even thought that superconductivity at a room temperature going down from the pages of science fiction novels and will become a reality. But after several years of rapid development of research in the field of high-temperature superconductors began to slow down.

Currently, the world record for high-temperature superconductors belongs to the substance, a complex copper oxide, calcium, barium, thallium and mercury, which becomes superconducting at 138 (-135 C). This relatively high temperatures are still very far from the room. But this is an important milestone. Nitrogen becomes liquid at a temperature of 77 K, and liquid nitrogen is about the same as ordinary milk. So for cooling of high-temperature superconductors can use conventional liquid nitrogen, it's inexpensive. (Of course, superconductors, the remaining are at room temperature, does not require cooling.)

Unpleasant more. Currently, there is no theory to explain the properties of high-temperature superconductors. Moreover, enterprising physics, which will be able to explain how they work, waiting for the Nobel prize. (In a known high-temperature superconductors atoms arranged in distinct layers. Many physicists believe that this is the layering of ceramic material enables electrons to move freely within each layer, thus creating superconductivity. But exactly how and why this happens is still a mystery.)

Lack of knowledge makes physicists to search for new high-temperature superconductors in the same old way, by trial and error. This means that the notorious superconductivity at a room temperature can be opened any time-tomorrow, in a year, or never. Nobody knows when you find the substance with such properties and whether it is found at all.

But if superconductors at room temperature will be opened, opening them, most likely, will cause a huge wave of new inventions and commercial applications. Normal, it may become a magnetic field, a million times stronger than the Earth's magnetic field (which is 0.5 Gauss).

One of the properties common to all superconductors, is called the Meissner effect. If you place a magnet above a superconductor, the magnet will hang in the air, as if supported by some invisible force. [The reason of the Meissner effect is that the magnet has the property to create inside the superconductor own mirror image, so the real magnet and its reflection begin to push off from each other. Yet another clear explanation of this effect is that the superconductor impervious to the magnetic field. He as it pushes magnetic field. Therefore, if you place a magnet above a superconductor, the lines of force of a magnet in contact with superconductor will be distorted. These power lines and will push the unit up, forcing him to levitate.)

If humanity will be able to use the Meissner effect, you can imagine the highway of the future with a coating of such special ceramics. Then with the help of magnets placed with us on the belt or on the bottom of the vehicle, we can magically to hover above the ground and carried to their destination without any friction or loss of energy.

The Meissner effect works only with magnetic materials such as metals, But you can use superconducting magnets and levitating nonmagnetic materials, known as the paramagnetic or diamagnetic. These substances do not themselves possess magnetic properties; they find them only in the presence and under the influence of an external magnetic field. The paramagnetic attracted external magnet, the diamagnetic repelled.

Water, for example, diamagnetic. Since all living beings are made up of water, they can levitate in the presence of strong magnetic fields. In the field with magnetic induction of about 15 Tons (30 000 times more powerful than Earth's magnetic field) scientists have managed to force to levitate small animals such as frogs. But if superconductivity at a room temperature will become a reality, it will be possible to lift into the air and large non-magnetic objects, using their diamagnetic properties.

In conclusion, we note that the force field in the form in which they usually describes a fantastic literature, not consistent with the description of the four fundamental interactions in our Universe. But it can be assumed that the person will be able to simulate many of the properties of these fictional fields using multilayer boards, including plasma window, laser veil, carbon nanotubes and substances with variable transparency. But really this the Board can be developed only in a few decades and even a century. And if superconductivity at a room temperature is detected, humanity will be able to use the powerful magnetic field; it is possible that with their help it will be possible to raise in the air cars and trains, as we see in science fiction movies.

Taking all this into account, I would say the force field to the class I impossibility, i.e. identified them as something impossible for today's technology, but implemented in a modified form in the next century or so.