Werner Heisenberg, discovering the matrix world of quantum field theory

Werner Heisenberg is one of the most famous physicists of the 20th century who managed to rewrite quantum mechanics in terms of matrices. He also established his position in the world of science by presenting principles that are fundamental concepts in physics today. In this article, we are going to review the life of Werner Heisenberg.

The study period of Werner Heisenberg

“Werner Carl Heisenberg» December 5, 1901 in the city Wurzburg, Germany was born. His father August Heisenberg was a researcher of ancient Greek language and modern Greek literature. He taught at the University of Würzburg. His mother is also “Ana Veklin”, the daughter of the president of the university.MaximilianIt was Munich. The birth of Werner Heisenberg in such a family caused him to study and acquire knowledge from his childhood. It is said that during school, his teachers were impressed by his mathematical intelligence; Because he was able to learn concepts faster than other students and discuss them despite his young age.

Heisenberg entered the University of Munich in 1920, when he was 19 years old, and after studying the introductory courses, he was apprenticed toArnold Sommerfeld» Income to study atomic spectroscopy and description of quantum models. About a decade ago, a scientist namedNiels BohrHe proposed the idea that there are certain properties in atomic physics that take only discrete values ​​and cannot be assigned continuous values. Heisenberg focused on this theory in his studies. He successfully defended his doctoral thesis in 1923.

Despite the fact that Werner Heisenberg did not succeed in extracting an impressive article from his thesis, he was able to explain the behavior of the spectral lines of the atom under the influence of the magnetic field. Heisenberg developed a model to describe this behavior; However, this explanation was accompanied by the introduction of half-correct quantum numbers, which contradicted Bohr’s theory at that time.

In 1922, while still officially a student of Sommerfeld, Heisenberg became a research assistantMax Bourne» was at the University of Göttingen; where Heisenberg first met Bohr. In 1924, he succeeded in getting teaching qualifications in German universities.

The foundation of quantum mechanics

In 1925, Werner Heisenberg, after a long visit to the Bohr Institute for Theoretical Physics at the University of Copenhagen, studied the intensity of the electron spectrum, considered as a harmonic oscillator. His position based on this theory should be based only on observable quantities. He published the results of his studies on this issue under the title of an article with “Reinterpretation Quantum-theoretical kinematic and mechanical relationsHe published in 1925.

Werner Heisenberg’s formalism was based on immutable multiplication. At the same time, Bourne, along with a student namedPasquale JordanThey found that these results can be expressed in matrix algebra. In November of the same year, Bourne, Heisenberg and Jordan published an article on “quantum mechanicsThey wrote that he became famous during that time; So that it was referred to as the basic document of the new quantum mechanics.

Werner Heisenberg’s Uncertainty Principle

During those years, other formulations of quantum mechanics were being developed: Brackett’s notation, developed using vectors in Hilbert space, was another breakthrough in quantum mechanics. On the other hand, the wave equation given byErwin Schrödinger“, wrote the Austrian physicist, worked well. At that time, Schrödinger showed that in quantum mechanics, different formulas are mathematically equivalent; Although the importance of discovering this point was not very clear in those years.

After the aforementioned article in quantum mechanics, Heisenberg increased his studies in this field and succeeded in writing an article entitled “The perceptual content of theoretical quantum mechanicsHe wrote that he became famous in the world of science.

In this article, he statedUncertainty Principle” the payment. According to Werner Heisenberg, quantum mechanics has shown that the momentum and position of a particle cannot be measured exactly at the same time and with the same precision. Instead, a relationship between the changes of these two quantities with a numerical constant value called “Planck’s constant» exists, which states that if the uncertainty in one variable decreases, the uncertainty in the other quantity increases reciprocally. There is a similar relationship between energy and time variables.

Heisenberg made a deep philosophical conclusion: it is impossible to accurately determine the state and characteristics of a physical system; Because it is not possible to simultaneously know the position and movement (as initial conditions) with high accuracy. Therefore, the use of probabilistic formulas in atomic theory comes from the necessarily uncertain relationship between variables.

Nobel Prize

In 1927, Heisenberg became a professor at the University ofLeipzig” Meeting. In those years, Heisenberg turned to study the theory describing the atomic nucleus; Because the neutron had just been discovered and it seemed like an interesting topic. He managed to discover a force calledstrong force” became. This force describes the interaction model between proton and neutron.

Werner Heisenberg finally won the Nobel Prize in Physics in 1932.

On the other hand, Dirac, Jordan andWolfgang Paioliwho were studying the creation of a quantum field theory, won the Nobel Prize in 1933. Quantum field theory tries to unite quantum mechanics and relativity theory with the aim of understanding the interaction between particles and forces.

The cause of war is found!

In the same year that Werner Heisenberg won the Nobel Prize in Physics, the Nazi Party was gaining power in Germany. This party, which was actually the egalitarian party of the German working class, believed that the NazisNon-Aryan” or politically unreliable should be removed from their government jobs – the Nazis believed that their roots were Aryan.

Among those who, according to this belief, should have been fired from university professorships, were Born, Einstein, Schrödinger and a number of Heisenberg’s students and colleagues in Leipzig. Heisenberg tried to express his protest in a calm and logical manner, but after despairing of the Nazis changing their beliefs, he could only hope that the Nazi Party would soon be abolished.

During these years he apparently never thought of leaving Germany. Although he could certainly have risen to professorships in American universities, he was gripped by a strong sense of national loyalty that separated politics from patriotism for him.

WWII

The discovery of nuclear fission put the nucleus of the atom in the center of attention. After the German invasion of Poland in 1939, Heisenberg was called by the military to study the problem of nuclear energy. At first, in addition to his scientific activity at the University of Leipzig, he worked at the Institute of PhysicsKaiser WilhelmHe was also in Berlin to continue his studies. Finally, in 1942, he was chosen as the director of this institute and assumed the main role in German nuclear research. Given the motivations of the Nazi Party, this position was extremely dangerous.

Of course, his research group was unsuccessful in producing a reactor or an atomic bomb. Some critics believed that his lack of success was due to his lack of knowledge about atomic bombs. But others believe that he deliberately sabotaged the creation of the atomic bomb. But it cannot be ignored that there were important mistakes in his research, which ultimately led to his failure in this field.

Thus, it is clear that the German nuclear weapons project did not progress much compared to the United States. But factors beyond Heisenberg’s control played a more fundamental role in the final result. The German Minister of Armaments and War, after a conference in 1942, announced that the research of the reactor should be continued by other scientists; Even if the probability of building a bomb for use in World War II is slim.

During the war years, there were discussions about Werner Heisenberg’s speeches in countries such as Denmark and the Netherlands, which were to be taken over by Germany. These trips necessarily had to be made with the approval of the German authorities and thus indicated the support of the Nazi leaders for Heisenberg and vice versa.

His most infamous speech was during a trip to Copenhagen in 1941, during which he raised the issue of nuclear research with Bohr, causing Bohr to worry about his position. However, Heisenberg later claimed that there had only been a misunderstanding and that he had not intended to jeopardize Bohr’s position.

In 1945, after the atomic bombing of Hiroshima, Japan and the arrest of Heisenberg by the British, it became clear that Werner Heisenberg had no understanding of some basic principles of bomb design – for example, determining the critical mass of the bomb.

What did Werner Heisenberg do in the years after the war?

Heisenberg was released by the British authorities in 1946 and obtained a managerial position at the Kaiser Wilhelm Institute. In the same years, this institution was changed to “Max Planck» The name was changed. In the post-war years, Werner Heisenberg assumed various positions as manager and spokesman of the German government, which was in fact a political role and differed from his position as a scientist before 1945.

Beginning in 1952, he played an important role in Germany’s participation in the creation of a nuclear research center.CERN” had In 1953, he became the head of the third branch of the Foundation.Humboldt» was chosen. With the help of the government budget, this institute financed the education of foreign researchers to conduct research in Germany.

Heisenberg’s activities continued in parallel in the world of science and politics until the end of his life. Werner Heisenberg finally died in 1976 in Munich, Germany.