It's a joyful thing   to know that you are truly a physicist. What else besides love can compare with it? (E.P.W.)

-- Like all children, I was born without my permission. What a pity it is that we cannot recall the day of our birth. What a memory that would be! But as soon as I realized that I was alive, I was curious about the world and happy with it. At least internally, I thanked my parents for having given me life -- Wigner told Andrew Szanton who has written the most comprehensive biography about him.

Wiegner means cradle-maker in German and this was shortened to Wigner in Hungary. Eugene corresponds to the Hungarian given name Jenő. It's a bit of a formal grownup name, therefore the small boy was simply called Jancsi (Johnny) in the family. (Later on, in America, Eugene signed his letters mailed to friends as Wigwam, to be more personal.)

Eugene said about Budapest that -- you heard a great deal more erudite conversation than you hear in the United States -- people talked more about culture. [Blumberg--Owens] -- Szanton has described how dearly Wigner loved Hungary. When Szanton mentioned that he wanted to ask about Hungary, Wigner answered: -- Good! -- clapped his hands, and said with his "wonderfully rich, heavily accented voice":

-- Simple Hungarian poems and songs that I learned before 1910 still come to me unbidden. After 60 years in the United States, I am still more Hungarian than American, much of American culture escapes me. Jokes are apparently universal, but no country could possibly love them more than Hungarians did. I have never known such a taste for jokes in all the years since I left Hungary; certainly not in Germany and not in the United States either. Food and shelter are necessities, but laughter is not. So why do we invent jokes with such skill, and laugh at them with pleasure? -- Another Hungarian, Arthur Koestler wrote a treatise about laughter, discussing the interrelation of humor, discovery, and art [in the The Act of Creation ]. Wigner especially liked Hungarian poetry, -- perhaps the finest in Europe. -- He liked to recall long texts from his favorite poet, Vörösmarty, even in his late years. -- In Budapest there were many cafés, of a kind that hardly exist in the United States. In such places, you were not only allowed to linger over coffee, you were supposed to linger, making intelligent conversation about science, art, and literature.

In 1919, after the collapse of the Austrio--Hungarian Empire the communists took over in Budapest. Their leader, Béla Kun was a Jew, indoctrinated in Russia as a prisoner of war. Most of his top commissars were Jews as well: they wished to get rid of the feudalistic-nationalistic supremacy of aristocratic landlords. After the fall of communism this created a further excuse for antisemitism. This was the reason why not only Theodore von Kármán, Arthur Koestler, Michael Polányi, and Leo Szilard (that time politically leaning towards the left), George de Hevesy (accused of cooperation with Theodore von Kármán), but later also John von Neumann, Edward Teller, and Eugene P. Wigner (coming from well-to-do capitalist families) -- emigrated from Hungary. -- Béla Kun can unwittingly take credit for the American preeminence in the development of nuclear energy -- as Stanley A. Blumberg and Gwinn Owens wrote. But this was not the reason why Béla Kun was executed by Stalin's purges in Russia in 1937.

-- Under the hardening conditions of World War I the communists began gaining strength in Hungary. My father deeply opposed them. Many of the top communist leaders were Jewish. As Jews became more associated with communism, my father arranged the conversion of his family to Christianity. For him Roman Catholicism seemed to be much like communism: a well-run dictatorship. He had been a student in the Lutheran Gymnasium, so it was natural for him to pick the Lutherans. [Wigner to Szanton.]

The well-to-do family sent Eugene to the Lutheran Gymnasium, which provided a lasting intellectual provision to him. He especially emphasized the impact of his mathematics teacher, László Rátz. who took special care with him, and also of his schoolmate, John von Neumann.

*

When Eugene became 17, he had to decide on his future profession.

-- My father came and asked me: -- "My son, when you grow up, what do you want to become?" -- After a short silence I answered: -- "Father, if I am to be frank with you I have to say that I would like to become a physicist." -- My father seemed to have expected this answer, and asked me: -- "Tell me, my son, how many jobs are available in our country for a physicist?" -- With some exaggeration I told: -- "I think, four." -- (In reality there were only three at the three universities.) -- "And do you think, my son, that you will obtain any of these four jobs?" -- This is how and why I chose studying chemical engineering. After the high school classes taught by Sándor Mikola, the lectures at the Institutes of Technology in Budapest and Berlin were mere repetitions. Essentially the physics lessons in the Lutheran Gymnasium were the last physics courses which I regularly attended. [To the author 1987.]

He was enrolled at the Budapest Institute of Technology in chemical engineering, but the new rightist military regime reduced the rights of Jews to attend university, thus Wigner left for the Institute of Technology in Berlin-Dahlem. There Wigner's consultant was Michael Polányi. -- After László Rátz of the Lutheran Gymnasium, Michael Polanyi was my dearest teacher -- remembered Wigner. -- His finest gift was to encourage young men with his very great heart. In all my life, I have never known anyone who used encouragement as skillfully as Polanyi. He was truly an artist of praise. -- In Berlin Wigner considered Polanyi to be as valuable a scientist as the Nobel laureates Laue, Nerst, Pauli.

-- Once I made a remark to Polanyi about the impossibility of an association reaction. He heard my idea without grasping it. Months later Polanyi told me, -- "I am quite sorry. This point which you have made on association reactions: I have heard that the same problem had been discussed in a very recent paper of Max Born and James Franck. (Both obtained Nobel Prizes later.) I told them that you had the same idea. I am quite sorry, I failed to understand you."

Wigner completed his Ph.D. thesis under the supervision of Michael Polanyi in Berlin. His thesis (published later in 1925 jointly with Polányi) treated the formation and decay of molecules.

-- As two hydogen atoms collide, they stick to a single molecule. After a bit of thinking I found it to be a miracle: the molecules have discrete energy levels. How do they know that they have to collide with just such an amount of energy? How do they manage that their angular momentum is an integer multiple of Planck's constant h/2p? I suggested that the energy of molecular levels is not sharply determined, because the excited molecular state may decay after a while into atoms. Even the conservation of angular momentum is not a completely strict law! At collision the value of the angular momentum jumps to the nearest integer multiple of Planck's constant h/2p. These were written down much before quantum mechanics was invented. This is why several people accused me of having invented Heisenberg's uncertainity relation which is not true. But my conclusions turned out to be right. [Wigner to the author in Budapest 1983.]

*

Anthony Wigner, himself being a director of a leather factory, worked hard to convince his son Eugene to study chemical engineering, which might become useful in the factory. Dr. Eugene Wigner worked in the tannery in Budapest (1925--1926), where he ordered the Zeitschrift für Physik. the avant-garde journal of modern physics. From this journal Wigner learned that quantum mechanics had been invented! After having read the paper of Max Born and Pasqual Jordan, which elaborated Heisenberg's quantum theory, he was in heaven. He could not resist the temptation of becoming an assistant at the Kaiser Wilhelm Institute for a salary of 136 marks per month. (It turned out that Polányi's helping hand was behind this invitation.) This is when Wigner's interest started in   s y m m e t r y. Let us listen to his recollection:

-- When I returned to Berlin, the excellent crystallographer Weissenberg asked me to study: why is it that in a crystal the atoms like to sit in a symmetry plane or symmetry axis. After a short time of thinking I understood: being on the symmetry axis ensures that the derivatives of the potential energy vanish in two directions perpendicular to the symmetry axis. (In case of a symmetry plane the derivative of the potential energy vanishes in one direction.) This is how I became interested in the role of   s y m m e t r i e s  i n  q u a n t u m  m e c h a n i c s . I spent the holidays -- Christmastime and summertime -- in Hungary, in Budapest and in Alsógöd, on the shore of the Danube. There I wrote the book on "Group Theory and its Application to the Quantum Mechanics of Atomic Spectra." [To the author 1983.] -- The intrusion of group theory into quantum mechanics was not received with applause. Wolfgang Pauli called the idea Gruppenpest. Albert Einstein and Erwin Schrödinger also expressed their uneasiness. Max Born and Max von Laue were more encouraging. John von Neumann and Leo Szilard enthusiastically encouraged Wigner's efforts. It was worth to do so: these efforts later resulted in a Nobel Prize.

If an experiment is repeated elsewhere in another laboratory under similar conditions, it will give identical result. The experiment today yields the very same result as it yielded yesterday. If we turn the whole equipment by 300, it will not influence the result. The outcome depends neither on the location and timing of the experiment, nor on the spacial orientation of the equipment. Even speed (e.g. that of the Earth) does not influence the way the laws of Nature work. To express this  b a s i c  e x p e r i e n c e  in a more direct way: the world does not have a privileged center, there is no absolute rest, preferred direction, unique origin of calendar time, even left and right seem to be rather symmetric.

The interference of electrons, photons, neutrons has indicated that the state of a particle can be described by a vector. possessing a certain number of components. As the observer is replaced by another observer (working elsewhere, looking at a different direction, using an other clock, perhaps being lefthanded), the state of the very same particle is described by another vector, obtained from the previous vector by multiplying it with a matrix. This matrix transfers from one observer to another.

The symmetry transformations in Euclidean space and time play such important roles in nature that their generators have deserved specific names: momentum, angular momentum, center of mass coordinate, energy, parity. Actually, the energy generates the change of the time coordinate: it transforms present to the future. Thus the symmetry generators express the dynamics (how the future evolves from the present), the structure (how objects interact by exchanging momenta), and also the outcome of our measurements (how a human brain observes the state of objects). From these symmetries of Nature the conservation of momentum, speed of center of mass, angular momentum, energy and parity follows.

If a body is rotated by 900 around the x-axis, and after that around the y-axis, the outcome differs from the outcome of a y first, x second rotation. Rotations don't commute; their generators, the components of angular momenta don't commute. This simple everyday experience of non-commutability of transformations in the three dimensional space and time implies that the corresponding matrices cannot be diagonalized simultaneously, therefore the corresponding quantities cannot be exactly measured at the same time. The uncertainty relation of angular momenta (furthermore uncertainity relation between time and energy) was recognized by Wigner before 1925 while working on his Ph.D. thesis, well before Heisenberg's deduction of the uncertainity relation. The extra power of left/right reflection symmetry -- resulting in the parity conservation law, leading to specific selection rules in atomic spectra -- was recognized by Wigner.

In 1930 Wigner showed the utmost power of these experienced symmetry properties of space and time in quantum mechanics. His book has become one of the most important classics of the new science, having been published in German, English, Japanese, and Hungarian. The author is convinced that the long-lasting essence of quantum mechanics has been understood by Eugene Wigner: the basic experiences of superposition and symmetry will serve as a lasting foundation; it will influence how this intellectual achievement of the 20th century with utmost importance will be taught in the schools of the 21st century. (When this was told to Wigner, he sharply disagreed. According to him only one person understood quantum mechanics: John von Neumann. )

Wigner received the Nobel Prize in 1963 for his contribution to the theory of the atomic nucleus and the elementary particles, particularly through the discovery and application of fundamental symmetry principles.

*

History reached again Wigner in Berlin: Nazism was at the corner. Thus he accepted the invitation from Princeton University. Cornelius Lanczos, John von Neumann, Edward Teller, and Eugene Wigner were called to America to teach the New Physics to the New World. For their advanced understanding of these revolutionary scientific ideas and their special political instinct they were called the Martians. Neumann, Szilard, and Teller enjoyed being called Martians, only Wigner did not. He considered himself to be the slowest among the four friends, but he was the one not only sparkling with ideas but completing works. This is why it was he who received the Nobel Prize. Wigner enjoyed Teller's wide interest and lightning logics. He acknowledged Szilard's originality, but was puzzled by his pushy character, opposite to Wigner's polite modesty. But he admired the superiority of Neumann's brain the most.

The late 1920s and the 1930s were heroic times for quantum mechanics: it was successfully applied to explain the empirical facts collected in spectroscopy, chemistry, atomic physics, molecular physics, solid state physics, nuclear physics. Eugene Wigner and his students like John Bardeen (later  Nobel laureated twice, the only one in physics) and Frederic Seitz (later president of the National Academy of Sciences) played a leading role. Wigner published over 60 fundamental papers in these years, alone and with such celebrities as Michael Polanyi, Pasqual Jordan, John von Neumann, Victor Weisskopf, Frederick Seitz, John Bardeen, George Breit, R. Smoluchowski, and Edward Teller.

From time to time Wigner visited Hungary to spend holidays with his family, and to lecture at the Colloquium organized by Rudolf Ortvay about quantum mechanics in Budapest. Professor Ortvay once invited Paul Adrien Maurice Dirac, the Nobel laureate creator of relativistic quantum mechanics, to lecture at his Colloquium. Dirac was known to be withdrawn, not interested in social activities. Therefore it was a great surprise when in the next year Dirac himself offered a new visit and lecture to Ortvay. Dirac arrived, "by chance" his visit happened in coincidence with that of Wigner, and they both spent a relaxing holiday at Lake Balaton, together with Wigner's sisters. After one of his prominent visits, the deeper reason for Dirac's interest in Hungary became understood: he married Manci Wigner.

*

The neutron, a new nuclear particle with zero charge, was discovered in 1932. Wigner Jenő published his first paper on nuclear physics in Hungarian, in the periodical of the Hungarian Academy in 1932, about the theory of neutrons. He showed how quantum mechanics can be used to understand nuclear properties. Hideki Yukawa began his Nobel lecture by saying:

-- Wigner pointed out that nuclear forces between two nuclear particles must have a very short range, in order to account for the rapid increase of the binding energy from the heavy hydrogen to the helium.

Wigner recognized a new symmetry in Nature which manifests itself in the conservation of the total number of protons and neutrons. (Antiprotons and antineutrons are counted with minus signs.) Proton and antiproton can annihilate each other, but our world -- made of common matter, consisting only of protons (furthermore neutrons and electrons), which have survived billions of years due to the conservation theorem of baryonic charge.

In the meantime history took sharp turns, and Wigner played a decisive role in them. In the 1930s Wigner studied the theory of nuclear reactions (esp. those initiated by neutrons). Thus, as Leo Szilard brought the news about the discovery of uranium fission in January 1939, they immediately understood its importance in enabling a neutron chain reaction, and elaborated a theory for it. Wigner's close link to the other Princeton professor, Albert Einstein, was essential in sending the historic letter to President Roosevelt. Wigner's role in the Manhattan Project made history: he designed the large reactors in Hanford, which supplied plutonium for the Nagasaki bomb. After the collapse of Nazi Germany, his Central-European historical instinct led him to join Szilard's efforts to prevent the use of atomic weapon against the Japanese. After Nagasaki, after World War II he became director of the Oak Ridge National Laboratory, leading the design of new nuclear reactors. He obtained 37 patents. But the causalities in Hiroshima and Nagasaki haunted his conscience throughout his life: was dropping the bomb on cities really necessary? [Budapest 1987.] This made him propose the defense program against nuclear weapons. This made him think about the future.

*

-- Eugene and Heckmann were lying on the lawn near the municipial swimming pool in Göttingen. Heckmann (a German astronomer) observed that a trail of ants was crawling across Eugene's right leg, and he asked Eugene "Don't they bite?" The answer was "They do." Question: "Then why don't you kill them?" Eugene Wigner: "I don't know which one it was." -- This story was told by Edward Teller [in the foreword of Wagner's book on Wigner]. According to his other story, while Wigner was driving in Princeton, another car crossed the street unexpectedly. As the blood pressure went up, Wigner shouted at the other driver: -- Go to hell -- please! [Valentine Telegdi to the author.]

According to John von Neumann, when Leo Szilard entered a revolving door following somebody, he somehow managed to come out first. Not so with Wigner. If you are accompanied by Wigner, and let him enter the revolving door first, he manages to leave it last. -- In America every physicist knows Wigner's modesty -- Valentine Telegdi said [in a lecture in Hungary 1989]. -- This is, however, an "apparent" modesty. Wigner knows his own value very well, the modesty serves only as a defense against provocation. -- Edward Teller characterizes Wigner: -- When he says to a seminar speaker: "What you say is interesting," that is a much harder criticism than my saying to the speaker: "That's damned nonsense." -- (The author of the present booklet experienced this behavior of Eugene Wigner upon himself.)

As a small child, he was taken on an excursion in a carriage. Eugene was supposed to chat politely with grownups, but he would have preferred talking with the horse. Unfortunately, the horse did not speak Hungarian. But he kept this kind of interest through his whole life.

Albert Einstein -- and a lot of other giants of physics -- had reservations with respect to quantum mechanics because it is not deterministic in the strict Newtonian sense. One can compute the time evolution of the wave function, but at the instant of measurement the wave function suddenly shrinks to one of the eigenfuntions of the measured quantity, and we cannot predict exactly to which of them. Quantum mechanics offers only probabilistic prediction about the outcome of a measurement, and about its impact upon the state of the microobject. -- But what is a m e a s u r e m e n t ? -- asked Wigner. He tried to give himself an answer. It is the interaction of the real outside world with the mind of the physicist. This has raised the further question of consciousness. What happens if a human looks at the measuring device but he misses appreciating the position of the dial? And do animals possess consciousness? In his last years, Eugene P. Wigner thought more and more about consciousness and its relation to quantum mechanics. In his acceptance lecture for the honorary Ph.D. degree at Eötvös University, Wigner expressed his personal opinion [ The Future of Physics, printed in the Heavy Ion Physics Volume 1, a Wigner Memorial Volume, Budapest 1987]:

-- There are phenomena which physics cannot yet describe. For example, it cannot describe life, emotion, or consciousness. This situation is like not taking gravitation into account would be. But gravitation exists and life exists. I am here, I feel joy and desire. It used to be said that man is subdued to the laws of physics, and his emotions are irrelevant. I cannot accept that! I am convinced that the sequence of events is influenced by my consciousness in a similar way as it is influenced by the force of gravity. If this were true, there would be something which physics is not interested in as it was not interested in the existence of atoms 100 years ago.

-- I can imagine that the human intellect has its own limitations just as the animal brain is limited. Once I tried to teach the multiplication table to a nice and skillfull dog. Not to make a difficult calculation like 6× 8. Rather, I showed him 2 squares and 3 squares, and I wanted the dog to indicate that the product makes 6 squares. I failed. The dog can learn very different skills, but it seems not to be interested in multiplication. Up to a certain degree we are like animals. It is quite possible that our interest and our knowledge is limited as well. I would like to hope that understanding  l i f e  does not lie beyond the limits of our intellect. We have learned to describe the behavior of gases and the behavior of atoms. Once perhaps we shall understand life as well. This is why one cannot exclude that a deterministic description of the human mind will not be possible. It may be that present physics will be enough to descibe a bacterium.When it succeeds,the bacterium will not be considered to be a l i v e any longer. But in order  to describe the whole complexity of life,including human c o n s c i o u s n e s s, we shall be unable to restrict ourselves to pure wave functions, because the impact of the macroscopic environment disturbs it immediately, e.g. by the cosmic background radiowaves, which are present everywhere with a temperature of 2.7 K. -- It is well possible that understanding consciousness remains as far from the human intellect as multiplication from my dog.

According to Wigner, Newton was the greatest physicist because he was able to condense all the knowledge about the physical Universe in the single volume of the "Principia." The early 20th century Wigner welcome the arrival of relativity and quantum theory because they promised a compact world picture again at the price of a certain abstraction. As a matter of fact, Wigner's monography on Group Theory and its Application to the Quantum Mechanics of Atomic Spectra is a rather successful attempt to offer this synthesis for the 20th century. Seeing the expansion of physics, the recent flood of scientific information filled him with anxiety. At the age of 85 he was asked by Hungarian secondary school students about his view of the future (1987):

-- Well, please, it is a hard question. The realm of physics has been extended tremendously. In the first book I ever read about physics when I was 17, [written by Sándor Mikola] it said: "Atoms and molecules may exist but this is irrelevant from the viewpoint of physics." Only chemists were interested in atoms. It is marvelous that physics succeeded in explaining atoms. It is not clear whether such a success will be also reached in the future. How far humans can progress in science is not clear.

-- Physics has offered me a lot of joy. I loved physics. I still love it. But I cannot grasp a considerable part of recent physics: it is getting too complex and too sophisticated for me. But if a single person is able to catch only smaller and smaller fractions of science, and cannot understand the essence of science, young people may lose their interest in it. Today it is almost impossible to know the whole of physics. I consider this complexity to be a danger for the future of science. If people don't get an overview, they may lose interest. If they are not interested, they will not learn science. If young people do not study science, that will terminate the development of science.

-- I am deeply worried that we have not yet received any message from alien civilizations. It is probable that there are other habitable planets; people or other similar creatures may live on them. It is likely that some of these civilizations have developed more knowledge than we have. Therefore it is surprising that they have not established contact with us. I don't think on a direct visit because of the huge distances, but they might use telecommunication. I am surprised that there is only one earth and only one species which is interested. There are two possible explanations for this puzzle. One possibility is that they developed science and technology in the past, they started an arms race, and then they annihilated themselves and their whole planet. If this is a rule of the development of intelligence, it could explain the silence. Another possibility is that they developed science, which raised their standard of living. The luxury made them lazy, they gave up reading books and learning science. It is also possible that physics turned out to be too complicated for them, thus they found it boring, and stopped being interested in science. This is why those beings ahead of us by 50 years or more are not interested in contacting us. I hope I am wrong. I hope my fear of an end of the story is mistaken. I don't know.

In his last two decades Wigner Jenő visited his home country several times, lectured to students and professors, published in Hungarian, became an honorary member of the Eötvös Society, and also a member of the Hungarian Academy of Sciences. In 1995 he was buried in the Princeton Cemetery at the side of his former wife Mary. In Hungary, hundreds of people attended the Memorial Session on the 23rd of January 1995. In schools physics teachers spoke about his scientific and historic importance to their students. The New York Times printed a six-column obituary about the bold physicist who changed science's perception of subatomic particles and who helped usher in the Atomic Age:

-- Wigner was part of a circle of remarkably visionary scientists born and educated in Budapest who eventually came to the West and transformed the modern world.

(Author: George Marx)