Are force fields real

4. The final touches

A Force field (also: energy shield, protective shield or protective screen) in science fiction refers to a generally invisible barrier which, for example, is supposed to protect a spaceship from rockets, radiation weapons, cosmic rays or meteorites.

But what are force fields actually? The idea of ​​real existing force fields comes from the pen of the important English natural scientist Michael Faraday. Faraday lived in the 19th century and belonged to the working class. His father was a blacksmith, and in the first years of the 19th century the young Michael had a poor existence as an apprentice bookbinder. He was fascinated by the amazing breakthroughs that came with the discovery of the mysterious properties of two new forces, electricity and magnetism. Faraday devoured everything he could find on these subjects and attended Professor Humphry Davy's lectures at the Royal Institution in London.

Until said Professor Davy suffered serious eye injuries one day as a result of a tragic chemical accident and then offered the bright Faraday a job as his secretary. Over time, Faraday gained the trust of scientists at the Royal Institution and was allowed to conduct important experiments of his own, although he was not always treated with respect. Over the years, Professor Davy became increasingly jealous of the genius his young assistant displayed. His fame spread among experimental physicists and eventually outshone Davy's own reputation. When the professor died in 1829, Faraday made a few spectacular breakthroughs that led to the creation of generators that would soon power entire cities and change the course of world civilization.

The key to Faraday's greatest discovery was his "force fields". If you distribute iron filings on a magnet, you will see that the filings create a spider web-like pattern that takes up the entire space. These are Faraday's lines of force that describe in graphic form how electrical and magnetic fields of force penetrate space. For example, if you want to graphically represent the earth's magnetic fields, then the lines in the north pole region emerge from the earth and end in the earth again in the south pole region. If you wanted to draw the electric field lines of lightning during a thunderstorm in a similar way, you discovered that the lines of force concentrate at the tip of the lightning rod. From Faraday's point of view, the empty space was not empty at all, but filled with lines of force that could set distant objects in motion.

Faraday was mathematically illiterate due to his youth spent in poverty, which is why his notebooks do not contain formulas, but hand-drawn power line diagrams. Ironically, it was precisely his lack of mathematical knowledge that led him to draw beautiful diagrams of lines of force that can now be found in every physics textbook. Mathematically highly educated theoretical physicists deal with Faraday's concept, which he had designed because it was not mathematically formed.

Today, force fields are considered to be one of the most important concepts in the history of science. Because in fact all modern physics is written in the language of the Faraday force fields. In 1831 he achieved the decisive breakthrough that changed civilization for all time. One day he moved his toy magnet over a coil of wire and found that this way he could generate electrical current in the wire without even touching it. This meant that the invisible field of the magnet - across the empty space - could set electrons in motion in a wire and generate electricity in the process.

Faraday's "force fields," previously thought to be senseless, unfounded scribbles, were suddenly real material forces that could move objects and generate electrical power. Today the falling of her cup this morning, the shining of the sun and her bedside lamp are described with the help of forces that can be understood as fields. In relation to your bedside lamp, this means the following: A moving magnet creates a force field that pushes the electrons in a wire and causes them to move in an electric current, and this electricity in the wire is used to make the lightbulb glow . The same principle is used all over the world to generate electricity to power cities. For example, water flowing over a dam sets a giant magnet in a turbine in motion, pushing electrons in a wire, which in turn generates electrical current that flows through high-voltage wires into our homes.

The force fields devised by Faraday are therefore the forces that supply us with electricity and thus drive our modern civilization. They have been inspiring physicists for 150 years now. Einstein felt inspired by them that he formulated his theory of gravity in terms of force fields. And people like the famous physicist Michio Kaku wrote down the string theory in the language of Faraday force fields and thus founded the string field theory.

There are four basic forces or fundamental interactions on which physical objects can influence one another. They can all be described in the field language as Faraday developed them. Unfortunately, however, none of them show the properties of the force fields that are described in most science fiction novels and that we look for. The forces are called as follows:

1.Gravity, the silent force that keeps our feet on the ground, that prevents the disintegration of the earth and stars, and holds the solar system and galaxy together. Without gravity, we would be repelled from the rotating earth at a speed of around 1,500 kilometers per hour and hurled into space. The problem is that gravity has exactly the opposite properties of a force field as we find it in science fiction. The gravitation has an attractive effect, the futuristic force field usually repulsive. In addition, gravity is, relatively speaking, extremely weak and functions over enormous astronomical distances, while force fields are described as impenetrable and their effect is very limited in space. For example, by moving the little finger that lifts a spring, we can cancel the gravity of an entire planet that weighs over six trillion trillion kilograms!

2.Electromagnetism, the power that, as already mentioned, makes our cities shine. Laser beams, radio, television, modern electronics, computers, the Internet, electricity, magnetism - are also all results of electromagnetic force. From the electronics technician's point of view, it is the most useful force that humans have ever acquired. And it has - in contrast to gravity - both attractive and repulsive. However, there are also some reasons why it would be completely unsuitable as a force field of a spaceship Enterprise. First of all, it can be neutralized without any problems. Plastics and other insulators can easily penetrate a strong electric or magnetic field. A piece of plastic thrown into a magnetic field would fall straight through. In addition, the electromagnetism acts over great distances and cannot be shielded so easily over a small area of ​​effect. Its laws are described by the equations that James Clerk Maxwell developed and which apparently do not allow force fields as solutions.

3rd and 4th The weak and the strong nuclear force, the two unknown forces. The weak nuclear force is the force of radioactive decay. It heats up the earth's core, which is radioactive. She is the force behind volcanoes, earthquakes and continental drift. The strong nuclear force holds the atomic nucleus together. The energy of the sun and the stars comes from the nuclear force that illuminates the universe. One of several problematic aspects of nuclear power is its short range. It does not work beyond the diameter of an atomic nucleus. Because it is tied to the properties of the core, it is extremely difficult to manipulate. At present, their only technical application is to smash subatomic particles in particle accelerators or detonate atomic bombs.

Although the force fields used in science fiction do not necessarily obey the known laws of nature, there are still some chances that the creation of a force field like from Star Trek could make possible. First, there might be a fifth force that hasn't shown up in the labs yet. Such a force could act, for example, over a distance of a few centimeters or a few meters, instead of across astronomical distances. So far, all attempts to trace the existence of such a fifth force have remained unsuccessful.

A second chance is in the plasma. A plasma is, so to speak, the fourth state of matter. The three familiar states of matter are solid, liquid and gaseous - but the predominant and much less known form of matter in the universe is plasma (a gas of ionized atoms). And because the plasma atoms are torn apart - electrons separate from the atom - they are electrically charged and can easily be influenced by electrical and magnetic fields. Here there is a real possibility of imitating force fields as seen in science fiction films. Plasmas are one of the most common forms of visible matter in the universe. They are components of the sun, stars and interstellar gas. We humans are not very familiar with plasmas because they rarely occur on earth, but we can perceive them in lightning, in the sun and in the housing of our plasma television sets.

You can heat a gas to a sufficiently high temperature and thereby generate a plasma that can be melted and redesigned using magnetic and electric fields. Conceivable shapes are panels or windows. In addition, such a "Plasma window"can be used to separate a vacuum from ordinary air. In principle, this would not only prevent the air from flowing out of a spaceship into space, but also one create a practical and transparent interface between space and spaceship.

The plasma window was invented in 1995 by physicist Ady Herschcovitch at Brookhaven National Laboratory in Long Island, New York. He developed it as a solution to the problem of welding metals with the help of electron beams. Hot gas flows from an acetylene welding torch, which melts the metal parts and then welds them together. With an electron beam, on the other hand, the workpieces can be welded faster, cleaner and cheaper than with conventional methods. However, electron beam welding is problematic because it has to take place in a vacuum. This requirement is extremely impractical because a vacuum box would have to be built for it, which may have the dimensions of an entire work area and in which no normal worker can work.

To solve this problem, Dr. Herchcovitch then the plasma window. It is less than a meter high and less than 30 centimeters in diameter. It heats gas to 6650 degrees Celsius, creating a plasma that is enclosed by electric and magnetic fields. As in any gas, these particles exert pressure, which prevents air from flowing into the vacuum chamber. If argon is used in the plasma window, it glows bluish, just like the force field in Star Trek.

The plasma window is widely used in aerospace and industry. A vacuum is often required for the manufacturing process of microstructures and dry etching techniques for industrial purposes. Working in a vacuum can be expensive. But with the plasma window, a vacuum can be created inexpensively and at the push of a button. But can the plasma window also be used as an impenetrable protective shield? Does it fend off a burst of cannon fire? For the future, a plasma window of much greater efficiency and higher temperature could indeed be envisaged, which could damage approaching projectiles or dissolve them in air. However, in order to generate a more realistic force field, as is common in science fiction, a combination of different, superimposed layers was required. Perhaps each layer alone is not strong enough to stop a cannonball, but combined with the others it could work.

The outer layer should, if possible, be a charged plasma window that is so strongly heated that it can vaporize metals. A second layer could be a curtain of high-energy laser beams, thousands of intersecting laser beams would create a grid that could heat incoming objects and effectively dissolve them into steam. A grid of carbon nanotubes, tiny tubes made from individual carbon atoms, could be installed behind this laser curtain.

Carbon atoms are tiny and many times more stable than steel. Although the current world record for a carbon nanotube is only 15 millimeters in length, it can realistically be imagined that one day we will be able to manufacture such tubes of any length. Assuming carbon nanotubes could be linked to form a giant grid, they could create a screen of enormous strength that would repel most objects. A screen constructed in this way would be invisible, as in science fiction, since no nanotube is larger than an atom. Nevertheless, this grid made of carbon nanotubes would be more stable than any ordinary material known to us (see also: space elevator).

Using a combination of plasma window, laser curtain and carbon nanotube screen, an invisible protective shield could be built that hardly any object could penetrate. However, even this multilayered shield would not have all of the properties that a force field has in science fiction - because it would be transparent and thus unable to stop a laser beam. In a battle with laser cannons, our multi-layer force field hybrid would be useless.

In order to effectively stop a laser beam, an advanced form of photochromic would also need to be applied to the shield. This process is used in sunglasses, which darken when exposed to UV radiation. The basis of photochromatics are molecules that exist in at least two states. In one stage the molecule is transparent and in the other, when exposed to UV radiation, it changes to an opaque form.

It is quite conceivable that one day we will be able to use nanotechnology to produce a substance that is as stable as carbon nanotubes. In addition, their optical properties can be changed when they are exposed to laser light. And so a shield could be able to repel a laser attack, a particle beam and all other conventional sci-fi attacks. The practical implementation of such a plasma window laser curtain carbon nanotube photochromic protective shield is of course still a long way off.

And attack defense isn't the only purpose force fields have to serve in science fiction films. They also serve as a platform to resist gravity. In Back to the Future Michael J. Fox moves on a hover board that resembles a skateboard, except that it hovers over the road. In view of the laws of nature as we know them today, such an anti-gravity apparatus is an impossibility. But magnetic floating boards and corresponding automobiles could become a reality in the future and give us the ability to lift heavy objects at will. A necessary condition for such magnetic hoverboards would be "superconductors at room temperature".

If we place two bar magnets with their respective north poles opposite each other, they repel each other. When we turn one of the magnets, the two magnets attract each other. The same principle, namely the mutual repulsion of the same poles, can be used to lift astonishingly heavy weights off the ground. In some countries, advanced magnetic trains are already being built that float directly above the route with the help of ordinary magnets.And since they are not subject to friction, they can reach record breaking speeds while floating on an air cushion.

So far, however, magnetic trains have been extremely expensive. One way to increase their efficiency would be to use superconductors, which lose their electrical resistance as soon as they have been cooled to just above absolute zero. Superconductivity was discovered in 1911 by the Dutch physicist Heike Onnes. If certain substances are cooled to minus 253 degrees Celsius, there is no longer any electrical resistance. Usually electrical resistance gradually decreases as the temperature of a metal decreases. The reason for this are random atomic vibrations that make it difficult for electrons to flow in a wire. If you lower the temperature, these random movements also decrease, so that the electricity flows with less resistance. But Onnes was amazed when he found that the resistance of certain materials suddenly drops to zero at a certain temperature.

Physicists immediately recognized the importance of this discovery. Power cables lose a significant amount of energy when carrying electricity over long distances. But if all resistance could be eliminated, the electrical force could be transmitted (almost) without loss. Indeed, if electricity could be made to circulate in a coil of wire, it would continue to circulate for millions of years without losing energy. In addition, one could build magnets of unbelievable power with comparatively effortlessly from these enormous electric currents and with their help lift huge loads. But despite all of these wonderful properties of superconductivity, the problem remains that it is very expensive to store giant magnets in barrels of supercooled liquid. Huge cooling machines are required to cool the liquids to near zero, which makes superconducting magnets prohibitively expensive.

But one day physicists might be able to create a superconductor at room temperature, the Holy Grail of solid-state physics. The invention of such a superconductor would set a second industrial revolution in motion. Powerful magnetic fields that could lift cars and trains would become so cheap that floating cars would be economically feasible. With superconductors at room temperature, the fantastic flying cars from the movies could be Back to the Future, Minority Report and war of stars Become reality.

In principle, you could then wear a belt made of superconducting magnets with which you would easily take off. For decades, physicists have searched unsuccessfully for superconductors at room temperature. It's been a lengthy, unreliable process of testing one material at a time. But in 1986 a new category of substances was found, which was called high-temperature superconductors and which already became superconducting at -183 degrees Celsius, which was a sensation for the physicist community. Suddenly all the dams seemed to be broken. For months, the physicists tried to outdo each other and break the next world record for a superconductor. For a brief period of time it looked as if at any moment the superconductors at room temperature from the science fiction books might land right in our living rooms. But after a few years of research at breakneck speed, the search for the high-temperature superconductor stalled.

Currently, the world record for a high-temperature superconductor is held by a substance called mercury-thallium-barium-calcium-copper oxide, which becomes superconducting at -135 degrees Celsius. This relatively high temperature is still far from room temperature, but this record is of crucial importance. Nitrogen liquefies at -196 degrees Celsius, and liquid nitrogen costs about the same as ordinary milk. So these high-temperature superconductors could be cooled quite inexpensively with them. Of course, room temperature superconductors do not require any cooling at all.

It is unfortunate that there is currently no theory that can explain the properties of these high-temperature superconductors. The active physicist who succeeds in this can count on the Nobel Prize. The high-temperature superconductors consist of atoms that are arranged in distinctive layers. Many physicists are of the opinion that this layering of the ceramic material enables electrons to move freely within each layer, creating a superconductor in the process. But how this works in detail remains a mystery.

Because of this knowledge gap, physicists unfortunately have to resort to rather uncertain methods to find new high-temperature superconductors. Which means that the fabulous superconductor at room temperature will perhaps be discovered tomorrow, next year or never. Nobody is in a position to make such a prognosis. However, should we actually discover it, this would trigger a chain reaction of commercial applications. Magnetic fields that exceed the earth's magnetic field by a million times over would be quite conceivable.

A common property of superconductivity is called the Meissner-Ochsenfeld effect. If you place a magnet over a superconductor, it floats in the air as if it were being carried by an invisible force. This effect results from the fact that the magnet creates a "mirror image magnet" in the superconductor, so that the real magnet and its mirror image repel each other. From another perspective it looks like this: Since magnetic fields cannot penetrate a superconductor, they are excluded. Therefore, when a magnet is held over a superconductor, its lines of force bounce off the superconductor, whereupon they push the magnet upwards so that it begins to float.

The Meißner effect makes it possible to imagine a future in which the motorway pavements are coated with this special ceramic. With magnets in the belt or in the tires of our cars, we would be able to float towards our targets as if by magic without friction or loss of energy. However, it only works with magnetic materials such as metals. But it is also possible to lift non-magnetic materials, which are called para- or diamagnetic, with superconducting magnets. These substances themselves have no magnetic properties; they only take on such characteristics in the presence of an external magnetic field. Paramagnets are attracted to an external magnet, while diamagnets are repelled. For example, water (H2O) is a diamagnet - and since all living things are made of water, they can float within reach of a strong magnetic field. Scientists have already made small creatures such as frogs float in a magnetic field of around 15 Tesla strength, 30,000 times that of the Earth's magnetic field. If room temperature superconductors were to become a reality, then large non-magnetic objects could also be lifted due to their diamagnetic properties.

We conclude that the force fields commonly described in science fiction literature do not fit the description of the four fundamental forces in the universe. However, it would be possible to simulate many properties of force fields using multilayered shields made up of a plasma window, laser curtains, carbon nanotubes, photochromic materials, and gravitational compensating magnets. But many decades, if not centuries, could pass before such a shield is developed. But if we should one day be able to generate a force field, we could be protected from almost any danger and trundle through the air and space with room temperature superconductors - just like in the legendary science fiction films.

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