It is the most revolutionary idea that appeared in physics according to the theory of relativity and the theory of amounts. But is it truthful?

Article of Prof.Eduard WITTEN (1987)

From Isaac Newton to Albert Einstein and Niels Bohr, the sommies of theoretical physics have tried to find links between the fundamental forces of nature. Today, Edward Witten is an important promoter of one of the most promising - and controversial - probable solutions of this problem the theory of ropes, a mathematical representation of a universe built not from particles similar to billiard balls, but of tiny circular strings vibrating in ten dimensions.

If it is correct, this theory possesses the potential to provide a single consistent explanation for everything in the universe, from the mechanisms inside the atom to the cosmos structure. But a human life may pass until the scientists will invent the means of verifying this theory.

In this article, K.C. Cole sketches a portrait of an extremely remarkable physicist who is working on the borders of mathematics and physics. << is extremely important to believe in what you do <<,Spune Edward Witten. << However, it is hard to keep your faith when everything is so speculative.

One of the teachings you draw is not to give up good ideas- but how can you know they are good?-

K.C. Cole has published numerous articles in Omni and The New York Times Magazine magazines and is the author of the volume entitled "Sympathetic Vibration: Reflection on Physics As a Gay of Life".

Recently, she conducted a study commissioned by Association of Science- Technology Centers and with the activity of women and members of minority ethnic categories in the field of science.

By measuring the room with big and secure steps, he holds his lecture as a conductor, the Ra-ta-ta of Crete on the board, ringing as a counterpoint of his high voice and which is sometimes almost imperceptible. He talks about «Vector bundles», «banal modules» and «free circular spaces». At one point he stops and says the following: «I have lived so far in a world of finished dimensions. And now I invite you to advance in a world of infinite dimensions ».

The teacher is Eduard Witten at the Institute of Advanced Study in Princeton (New Jersey).

At the age of 36, Witten is among the most important contemporary physicists. Currently, he is in New York to hold lectures at the Mathematics Faculty of Colombia University about the applications of physics in mathematics "!" Mathematics «A discipline that deals with abstract, intangible» relationships has always been a useful tool in physics "A discipline that deals with the concrete forces and objects of the real world." Witten turned everything upside down, trying to prove how physics can facilitate new discernment.

"It is not desirable to hurry to make comparisons with Einstein," says one of the members of the Faculty of Physics at Princeton University, "but when it comes to Witten" his arms open in a gesture of powerlessness. «He is with his head and shoulders above all others. He guided entire groups of people on new roads, created whole new fields. It shows elegant, formidable evidence that causes people to remain with their mouths, which arouse overwhelming feelings of admiration ».

Witten seems to be permanently everywhere, publishing scientific reports and taking lectures on cosmology, mathematics and different aspects of physics. Whenever he speaks, physicists listen to the tight attention.

Probably their attention was never greater than a few years ago, when Witten tried to seriously deal with a bizarre and long -forgotten theory that radically changes our conception of physical universal. Although it is difficult to present a contribution that made Witten become such a force in physics, his passion for this controversial theory makes him the most promoter of an idea that could be the most revolutionary concept in physics in the last 5 decades-as a revolutionary, Witten says.

If this theory is correct (and Witten believes that its validity will probably be proved in the end), it could provide completely new answers to the fundamental questions asked by philosophers, poets and theologians from the beginning of human civilization: Why is the universe as it is and what is the origin of matter?

«Strip theory» , or "string theory", as it is usually called (some scholars call it "Sueprsting Theory"), Eliminate the well -known image of a universe made up of particles of the kind of billiard balls, rejected and attracted by well -known forces such as gravity and electricity. The theory of quantities had already revealed, in the third decade of the current century, that billiard balls have certain strange properties that make them look like waves - they are more vibrations than defined in space. Now, The theory of strings assumes that these points are actually tiny circles, or closed "strings". The ropes vibrate invisibly in subtle resonances. According to the theory, these vibrations build everything that exists in the universe - from light to licorice, from gravity to gold.

Of course, these strings are not visible, nor can they be similar to the garters or with pieces of string. Since they cannot be detected with any of the means available to science today, they are mathematical curves. Talking about strings, just as talking about billiards balls or where, is a simple way to try to understand the unknown in known terms. The truth is that physics has always had to resort to metaphors. "When it comes to atoms," said the Danish physicist Niels Bohr, the father of the theory of quantities, "the language can be used in poetry. The poet is interested in the creation of images than the description of the realities."

The physicists defacted the atom and discovered, first, electrons, protons, and neutrons, and then, more exotic elements, such as neutrines and so -called quarks. I learned how nuclear force, gravity and electromagnetic force build from these molecules and galaxies. But, among other things, no one knows why there are electrons or why the particles are influenced by gravity. According to the opinion of her followers, the theory of strings has the potential to provide a single consistent explanation for absolutely everything, from the internal mechanisms of the Oana atom to the structure of the cosmos.

Unfortunately, the theory of strings contains what some scientists consider to be a great defect. The mathematical consistency that makes it so convincing is relevant only if we are willing to suspend our conception that the physical world is defined by four well -known dimensions (height, length, width and time) and suppose the existence of six other hidden dimensions - therefore, ten dimensions in total.

Imagine a closed rope-a circle-of fundamental matter of one kind or another.

Imagine then that the circle rotates, twists and vibrates only in the three ordinary spatial dimensions (plus the temporal dimension), but also in six dimensions that we cannot perceive.

The circle vibrates in countless tones, like a violin dimensional string that emits cosmic versions from or Mi bemol. If the string theory is correct, these vibrations may determine all the possible particles and forces of the universe.

If you ask them to give you a clearer explanation, Witten smiles and shrugs. "No one understands this much better than as I explained to you now," he says.

A ten-dimensions system does not bother Witten at any time: "These added dimensions are not more strange than many other things that physicists think." However, the notion of dimensional universe and the absence of any experimental data that could provide evidence in this regard made many physicists adopt a very skeptical position.

Obviously, the theory of strings has a lot to explain. For example, it will have to explain how it is done that the six additional dimensions remain invisible. The followers of this theory imagine these dimensions as being closely "wrapped" at billions of times smaller than that of an atom nucleus. However, they do not know why or when the six dimensions were wrapped. Some of these scholars think that it is simply possible that they have not expanded billions of years ago with the rest of the physical universe.

Such doubts do not diminish Witten's belief. "It is very possible that the proper understanding of the theory of the ropes will lead to the Dissolution of the continuity - space," he says. "The theory of strings is in a miracle."

Witten began to obtain offers of university chair positions only a few years after completing his studies at Princeton University, where he was employed as a professor at the age of 28. He was distinguished with a lot of prizes awarded by institutions around the world, including a "genius scholarship" from the MacARthur Foundation and recently, the prize awarded by the National Science Foundation to the most important young researcher.

In physics, the effort to find a definitive explanation has always been obviously countless times, physics has taken a step forward with the discovery that appearance in appearance were actually aspects of a single phenomenon. Newton's great discovery, for example, was that the same force that made the apple fall to the ground made the moon stay on its terrestrial orbit and that the Earth would stay on its solar orbit. For a long time there was the opinion that between magnetism, electricity and light there was no connection, until in the 19th century James Clark Maxwell and Michael Faraday discovered that all were manifestations of electromagnetism. The theory of relativity went from Einstein's effort to reconcile electromagnetism with classical mechanics.

Lately, physicists are obsessed with trying to unify the fundamental forces of nature - gravity, electromagnetism, the "strong" force (that force that ensures the cohesion of particles in the nucleus of an atom) and the "weak" force (which determines, among others the radioactivity, the spontaneous disintegration of the atomic nucleus).

Electromagnetism, strong and weak force and all the particles known as present in the universe can be explained according to the theory of quantities, something that Witten qualifies as "magic". This theory created a whole field of scientific research in which Witten himself has made a lot of important contributions. According to the theory of quantities, everything results from the interactions of the energy fields. The fields vibrate but not only in certain patterns or resonances that correspond to certain quantities (hence the term "amounts") of energy. These resonances are the known particles and forces of the natural universe, who use giant accelerators to crush atoms and find the particles that make them sometimes call their "resonance hunt" work.

The theory of quantities has managed to clarify many phenomena and led to the understanding of the subatomic processes, a fact resulting in the production of many wonders, from laser to semiconductors. However, the theory of quantities cannot explain gravity. Mathematical calculations that try to embrace gravity in this theoretical framework give unusable results.

However, gravity was in interaction with all types of energy present in the universe and a ray of light is influenced by it. Therefore, gravity must comply with the same laws of nature. But what are these laws?

Einstein has been striving for a long time to make a connection between gravity and electromagnetism so it can still explain the whole system of nature within a single "unified theory". He failed to do this. In 1919, however, Einstein received a letter from a physicist of German origin, a certain Theodor F.E. Kaluza, who believed that electromagnetism could be understood that a manifestation of gravity in a fifth dimension. Kaluza does not explain why the fifth dimension could not be perceived. In 1926, however, a Swedish mathematician, Oskar Klein, assumed that this was due to the fifth dimension exists on such a tiny scale that it influences anything, not even the size of a subatomic particle.

TThe string eoria is a new and more complex version of Kaluza-Klein theory. Like the fifth dimension postulated by Klein, the six additional dimensions postulated by the theory of the rope have "contracted", somehow until invisibility. The theory of strings argues that if we accept the notion of these six hidden dimensions, the mathematical inconsistencies that have prevented the previous attempts to reconcile the theory of quantity with gravity disappear as a miracle.

However, we cannot be sure that the theory of strings is a truthful representation of reality. Except for the mathematical consistency, there is no evidence regarding the existence of the six additional dimensions. Witten remarks, however, that over the last hundred years, the mathematical consistency has been "one of the most confidence of physicists."

To some extent, the theoretician world is by definition a personal world. The work does not require tubes or laboratories, cyclists or high capacity electronic computers, nothing but pencil and paper, and sometimes neither. Although among Witten's students were some who do specialization studies he hesitate to engage in his projects in which scientific speculation plays an important role, because, he says, he does not want to endanger their professional future.

Listening to Witten as he talks about his own career, you could gain the belief that becoming a physicist is almost ordinary. Although his father, Louis Witten, is a specialized physicist in studying gravity, he says he was not influenced by his family to too much. "I was about to do something else," he explains.

Witten grew up in Baltimore and graduated from the College courses of Brandeis University in Massachusetts with a diploma in history, although what interested him to a large extent was linguistic. Before starting his university specialization studies at Princeton, Witten wrote articles published in The Nation, The New Republic and other magazines. In 1972, he worked for six months in the campaign of the candidate for Presidency George McGovern as an assistant of one of his advisers for legislative issues. Witten said today that he does not possess the qualities required by a career in publicity or political especially the "sense of reality". When he started his studies at Princeton University, he was very close to choosing mathematics before deciding in favor of physics.

Witten's colleagues are much more generous with himself when it comes to his merits, especially his contribution to the attention of the theory of strings today.

The physicists did not endeavor to elaborate this theory, nor did they pay too much attention to the Kaluza-Klein theory. What happened was that they prevented them in the dark, then they tried to give it a precise form. "I don't think any physicist would have been insightful enough to invent the theory of strings intentionally," says Witten. "Fortunately, she was invented by chance."

In 1968, an Italian physicist Gabriele Veneziano, he was studying the strong force (the binder that unites the particles of the atomic nucleus) and simply overwhelmed what Witten calls "a formula that had some strange properties." A few years later, due to the research by Yoichiro Nambu from the University of Chicago and others, the physicists "realized that that bizarre formula was defining the vibrations of some strings."

For several years the theory of strings has aroused much interest. In the middle of the past decade, however, she had been largely abandoned, partly because other roads of thought seemed more promising and partly because of the Falţ that this theory involved the unacceptable idea of additional dimensions.

"When they realized it was plausible only in a decadimensional framework," says Witten, "most physicists left the ground." His own interest in this theory had been primarily aroused by the research done by physicists John H. Schwarz by la California Institute of Technology and Michael B. Green from Queen Mary College from London. Witten remembers that the effort to inform himself of this theory cost him "a few months of a difficult road". "It was different than anything else, he added," he added. "There is no one to give you encouragement."

It seems that the interest in the theory of strings was resuscitated by a series of reports issued by Schwarz and Green at the beginning of the current decade. In 1984 they published an important report that according to a Nobel laureate the physicist Steven Weinberg of Texas University gave an answer to a question that had been asked by Witten.

The question referred to the anomalies in the theories that were trying to unite the gravity with the quantum theory of the field. In the case of a theory anomalies are defective that generate absurd results that annihilate the theory, Witten as Luis Alvarez-Gaumé from Havard University has discovered a new class of abnormalities. At the same time, an even more important thing has shown (...)

The theory of strings assumes that if we could see the universe as a decadimensional ensemble, a new symmetry would appear, and all forces and particles would appear to us as the facets of a single coherent.

A layer that the origin of the anomalies was topological, in other words, it was related to geometric properties that do not appear in the presence of four dimensions, but appear in the presence of ten dimensions.

Witten considers the topology, which studies the properties of the geometric figures distorted or deformed in different dimensions, as a "mental bottom". The thought that topology could be unknown to specialists causes astonishment. "It's like when you say that I don't know how to speak in prose," he says, borrowing a joke of Moliere. A cup with a fate, for example, is the topological equivalent of a donut. respectively, but it does not change when you change the shape of the objects by bending. ” He admits, however, that the physicists did not take the topology in the past.

Witten attaches great importance to topology because the question if the real world can be explained by the theory of strings depends not only on the existence of additional dimensions, but also on the forms they take in space - if they are, say, the shape of the tubes, or the donuts, or if they are spheres.

In Flatland ”, the famous Victorian scientific-fantastic writing, Edwin Abbott eloquently demonstrated that what seems confusing and obscure in a dimension can become clear in another dimension. In his hypothetical world of two-dimensional triangles and squares, a three-dimensional sphere was an incomprehensible object. a point.

The theory of strings assumes that if we could see the universe in the decay, a new symmetry would make its appearance, and the confused multitude of forces and particles would prove to be only different facets of the same coherent.

Unfortunately, this adhesive symmetry inherent in decadimensional space is not easy to translate into particles and dimensional forces. Its perception requires incredibly subtle mathematical tools, tools that have probably not yet been invented.

A few years ago, Witten had a colleague conversation, and this discussion impressed him deeply. "They spoke of a very talented physicist who was not as productive as he could have been," explains' Witten. "And his opinion was that the reason was that the physicist never worked on the types of problems for which he was really the right man," Witten took the advice involved in his colleague. They consider themselves to be the right man to "take a problem of physics and find a solution based on bizarre mathematical operations." The "string theory" continues, "it will require a large amount of new mathematics - and the application of bizarre mathematics is my specialty." In the last few! years.

Witten stated that one of the protagonists of a new alliance between physicists and mathematicians, an alliance made by the theory of ropes. "I consider it as the number one protagonist," says I.M. Singer, professor of mathematics at the Massachusetts Institute of Technology "his intuition is fantasty". Witten himself considers some of his most important contributions as contributions to mathematics than physics.

Most of the great progress made by man in understanding the universe were due to close links between physics and mathematics. Newton had to invent a new type mathematics differentiated and completely-to complete its theory of gravity. Einstein's theory of general relative was based on a geometry of the curved space invented by the German mathematician F.B. Riemann in the middle of the 19th century. The theory of quantities required a tool called "functional analysis".

Witten says that the theory of strings "leads us to the borders of mathematics." But this does not intimidate them in the same way. "I realized that I could actually turn everything on the other side." he adds, and to obtain with the help of physics some surprising discernment about mathematics. ”

The new marriage between physics and mathematics has made for the first time the physical to be truly difficult for Witten. This is one of the reasons that determined him to accept the invitation to work at the prestigious Institute for Advanced Study, two steps from Princeton University, where he should not pay for the obligations of chair. "I want to work more intensely in fewer things," he confesses. All the "things" Witten is currently working on are aspects of string theory.

Witten's conclusions cannot be checked today in the laboratory, and this will not be possible in the foreseeable future. In fact, everything he does is so distant from the observable reality that a whole human life may pass or even more until the value of his theoretical discernment-and their possible practical applications-will become known. Theoretical physics is a risky job. "It is extremely important to believe in what you do," says Witten. "However, it is difficult to keep your faith when everything is so speculative."

"One of the teachings you draw," he continues, "is not to make mistakes - but that is not of too much use to you. Another teaching is not to give up good ideas - but how can you know they are good?"

Witten remarks that neutron stars and gravitational lenses - high concentrations of matter present in the cosmic space and, when observed from Earth, produce double images of the stars - were considered as fantastic notions, as pure speculation, until they were truly discovered. "The history of science is full of predictions that the validity of new ideas will never be proved. The history of physics shows that good ideas eventually prove to be correct."

Witten believes that string theory is a good idea to not be correct. It seems difficult and complicated, only because it is not well understood. The theory of strings is for now, according to Witten's opinion, "A piece of physics belonging to the 21st century and accidentally fallen in the 20th century." Physicists work today with only "A few crumbs compared to the great feast that awaits us."

However, Witten sometimes fears that difficulties will be too high. "The chances that this theory will lead us everywhere in the next few years are not too big.", admits the, "But if I didn't try, I would have the feeling that insight left me."

John Ellis one of the experts in theoretical physics of the European Center for Nuclear Research in Geneva, recently wrote the following: . "The phenomenology of the strings is still a young subject. There are numerous unanswered questions and technical problems, and it is easy to ridicule the totalitarian passion of the promoters of this theory. However, if it was to quote what was written on a candy cover that I have opened a few years ago," only ".

Or, in Witten's words: "If we get to prove the theory of strings, we will probably need luck. But in physics there are many ways to be lucky."