Heisenberg was raised and lived as aLutheran Christian.[8] In his late teenage years, Heisenberg read Plato'sTimaeus while hiking in theBavarian Alps. He recounted philosophical conversations with his fellow students and teachers about understanding theatom while receiving his scientific training in Munich, Göttingen and Copenhagen.[9] Heisenberg later stated that "My mind was formed by studying philosophy, Plato and that sort of thing"[10] and that "Modern physics has definitely decided in favor of Plato. In fact the smallest units of matter are not physical objects in the ordinary sense; they are forms, ideas which can be expressed unambiguously only in mathematical language".[11]
In 1919 Heisenberg arrived in Munich as a member of theFreikorps to fight theBavarian Soviet Republic established a year earlier. Five decades later he recalled those days as youthful fun, like "playing cops and robbers and so on; it was nothing serious at all";[12] his duties were restricted to "seizing bicycles or typewriters from 'red' administrative buildings", and guarding suspected "red" prisoners.[13]
In June 1922, Sommerfeld took Heisenberg to Göttingen to attend theBohr Festival, because Sommerfeld had a sincere interest in his students and knew of Heisenberg's interest inNiels Bohr's theories onatomic physics. At the event, Bohr was a guest lecturer and gave a series of comprehensive lectures on quantum atomic physics and Heisenberg met Bohr for the first time, which had a lasting effect on him.[14][15][16]
In his youth he was a member and Scoutleader of theNeupfadfinder, aGerman Scout association and part of theGerman Youth Movement.[22][23][24] In August 1923 Robert Honsell and Heisenberg organized a trip to Finland with a Scout group of this association from Munich.[25]
Heisenberg enjoyedclassical music and was an accomplished pianist; playing for others was a prominent part of his social life.[3] During the late 1920s and early 1930s he would often play music and dance at the Berlin home of his aristocratic studentCarl Friedrich von Weizsäcker, during which time he carried on a courtship with Carl's high-school-age sister Adelheid, which led to him being unwelcome at their home for a time.[26]Years later, his interest in music also led to meeting his future wife. In January 1937, Heisenberg met Elisabeth Schumacher (1914–1998) at a private music recital. Schumacher was the daughter of a well-known Berlin economics professor, and her brother was the economistE. F. Schumacher, author ofSmall Is Beautiful. Heisenberg and Schumacher were married on 29 April. Fraternal twins Maria and Wolfgang were born in January 1938, whereuponWolfgang Pauli congratulated Heisenberg on his "pair creation"—a wordplay on a process from elementary particle physics,pair production. They had five more children over the next 12 years: Barbara, Christine,Jochen,Martin and Verena.[27][28] In 1939 he bought a summer home for his family inUrfeld am Walchensee, in southern Germany.
From 1924 to 1927, Heisenberg was aPrivatdozent atGöttingen, meaning he was qualified to teach and examine independently, without having a chair. From 17 September 1924 to 1 May 1925, under an International Education BoardRockefeller Foundation fellowship, Heisenberg went to do research withNiels Bohr, director of the Institute of Theoretical Physics at theUniversity of Copenhagen. On 7 June, after weeks of failing to alleviate a severe bout ofhay fever with aspirin and cocaine,[30] Heisenberg retreated to the pollen-freeNorth Sea island ofHelgoland to focus on quantum mechanics.[31][32] His seminal paper, "Über quantentheoretische Umdeutung kinematischer und mechanischer Beziehungen" ("Quantum theoretical re-interpretation of kinematic and mechanical relations") also called theUmdeutung (reinterpretation) paper, was published in September 1925.[33] He returned to Göttingen and, withMax Born andPascual Jordan over a period of about six months, developed thematrix mechanics formulation ofquantum mechanics. On 1 May 1926, Heisenberg began his appointment as a university lecturer and assistant to Bohr in Copenhagen. It was in Copenhagen, in 1927, that Heisenberg developed hisuncertainty principle, while working on the mathematical foundations of quantum mechanics. On 23 February, Heisenberg wrote a letter to fellow physicistWolfgang Pauli, in which he first described his new principle.[34] In his paper on the principle,[35] Heisenberg used the word "Ungenauigkeit" (imprecision), not uncertainty, to describe it.[3][36][37]
In 1927, Heisenberg was appointedordentlicher Professor (professor ordinarius) of theoretical physics and head of the department of physics at theUniversity of Leipzig; he gave his inaugural lecture there on 1 February 1928. In his first paper published from Leipzig,[38] Heisenberg used thePauli exclusion principle to solve the mystery offerromagnetism.[3][20][36][39]
At 25 years old, Heisenberg gained the title of the youngest full-time professor in Germany and professorial chair[40] of the Institute for Theoretical Physics at the University of Leipzig. He gave lectures that were attended by physicists likeEdward Teller andRobert Oppenheimer,[40] who would later work on theManhattan Project[41] for the United States.
In early 1929, Heisenberg and Pauli submitted the first of two papers laying the foundation for relativisticquantum field theory.[43] Also in 1929, Heisenberg went on a lecture tour of China, Japan, India, and the United States.[36][42] In the spring of 1929, he was a visiting lecturer at theUniversity of Chicago, where he lectured on quantum mechanics.[44]
In 1928, the Britishmathematical physicistPaul Dirac had derived hisrelativistic wave equation of quantum mechanics, which implied the existence of positive electrons, later to be namedpositrons. In 1932, from acloud chamber photograph ofcosmic rays, the American physicistCarl David Anderson identified a track as having been made by apositron. In mid-1933, Heisenberg presented his theory of the positron. His thinking on Dirac's theory and further development of the theory were set forth in two papers. The first, "Bemerkungen zur Diracschen Theorie des Positrons" ("Remarks on Dirac's theory of the positron") was published in 1934,[45] and the second, "Folgerungen aus der Diracschen Theorie des Positrons" ("Consequences of Dirac's Theory of the Positron"), was published in 1936.[36][46][47] In these papers Heisenberg was the first to reinterpret theDirac equation as a "classical"field equation for any point particle ofspin ħ/2, itself subject to quantization conditions involving anti-commutators. Thus reinterpreting it as a (quantum[clarification needed]) field equation accurately describing electrons, Heisenberg put matter on the same footing aselectromagnetism: as being described by relativistic quantum field equations which allowed the possibility of particle creation and destruction. (Hermann Weyl had already described this in a 1929 letter toAlbert Einstein.)
Heisenberg'sUmdeutung paper that established modern quantum mechanics[48][a] has puzzled physicists and historians. His methods assume that the reader is familiar withKramers-Heisenberg transition probability calculations. The main new idea,non-commuting matrices, is justified only by a rejection of unobservable quantities. It introduces the non-commutative multiplication ofmatrices by physical reasoning, based on thecorrespondence principle, despite the fact that Heisenberg was not then familiar with the mathematical theory of matrices. The path leading to these results has been reconstructed by MacKinnon,[49] and the detailed calculations are worked out by Aitchison and coauthors.[50]
In Copenhagen, Heisenberg andHans Kramers collaborated on a paper on dispersion, or the scattering from atoms of radiation whose wavelength is larger than the atoms. They showed that the successful formula Kramers had developed earlier could not be based on Bohr orbits, because the transition frequencies are based on level spacings which are not constant. The frequencies which occur in theFourier transform of the classicalsharp series orbits, by contrast, are equally spaced. But these results could be explained by a semi-classicalvirtual state model: the incoming radiation excites the valence, or outer, electron to a virtual state from which it decays. In a subsequent paper, Heisenberg showed that this virtual oscillator model could also explain the polarization of fluorescent radiation.
These two successes, and the continuing failure of theBohr–Sommerfeld model to explain the outstanding problem of the anomalous Zeeman effect, led Heisenberg to use the virtual oscillator model to try to calculate spectral frequencies. The method proved too difficult to immediately apply to realistic problems, so Heisenberg turned to a simpler example, theanharmonic oscillator.
The dipole oscillator consists of asimple harmonic oscillator, which is thought of as acharged particle on a spring, perturbed by an external force, like an external charge. The motion of the oscillating charge can be expressed as aFourier series in the frequency of the oscillator. Heisenberg solved for the quantum behavior by two different methods. First, he treated the system with the virtual oscillator method, calculating the transitions between the levels that would be produced by the external source.
He then solved the same problem by treating the anharmonic potential term as a perturbation to the harmonic oscillator and using theperturbation methods that he and Born had developed. Both methods led to the same results for the first and the very complicated second-order correction terms. This suggested that behind the very complicated calculations lay a consistent scheme.
So Heisenberg set out to formulate these results without any explicit dependence on the virtual oscillator model. To do this, he replaced the Fourier expansions for the spatial coordinates with matrices, matrices which corresponded to the transition coefficients in the virtual oscillator method. He justified this replacement by an appeal to Bohr's correspondence principle and the Pauli doctrine that quantum mechanics must be limited to observables.
On 9 July, Heisenberg gave Born this paper to review and submit for publication. When Born read the paper, he recognized the formulation as one which could be transcribed and extended to the systematic language of matrices,[51] which he had learned from his study underJakob Rosanes[52] atBreslau University. Born, with the help of his assistant and former studentPascual Jordan, began immediately to make the transcription and extension, and they submitted their results for publication; the paper was received for publication just 60 days after Heisenberg's paper.[53] A follow-on paper was submitted for publication before the end of the year by all three authors.[54]
Up until this time, matrices were seldom used by physicists; they were considered to belong to the realm ofpure mathematics.Gustav Mie had used them in a paper on electrodynamics in 1912 and Born had used them in his work on the lattice theory of crystals in 1921. While matrices were used in these cases, the algebra of matrices with their multiplication did not enter the picture as they did in the matrix formulation of quantum mechanics.[55]
In 1928, Albert Einstein nominated Heisenberg, Born, and Jordan for theNobel Prize in Physics.[56] The announcement of the Nobel Prize in Physics for 1932 was delayed until November 1933.[57] It was at that time announced that Heisenberg had won the Prize for 1932 "for the creation of quantum mechanics, the application of which has,inter alia, led to the discovery of theallotropic forms of hydrogen".[58][59]
The development of quantum mechanics, and the apparently contradictory implications in regard to what is "real" had profound philosophical implications, including what scientific observations truly mean. In contrast to Albert Einstein andLouis de Broglie, who were realists who believed that particles had an objectively true momentum and position at all times (even if both could not be measured), Heisenberg was an anti-realist, arguing that direct knowledge of what is "real" was beyond the scope of science.[60] In his bookThe Physicist's Conception of Nature,[61] Heisenberg argued that ultimately one only can speak of theknowledge (numbers in tables) which describes something about particles but they can never have any "true" access to the particles themselves:[60]
We can no longer speak of the behaviour of the particle independently of the process of observation. As a final consequence, the natural laws formulated mathematically in quantum theory no longer deal with the elementary particles themselves but with our knowledge of them. Nor is it any longer possible to ask whether or not these particles exist in space and time objectively ...When we speak of the picture of nature in the exact science of our age, we do not mean a picture of nature so much as apicture of our relationships with nature. ...Science no longer confronts nature as an objective observer, but sees itself as an actor in this interplay between man and nature. The scientific method of analysing, explaining and classifying has become conscious of its limitations, which arise out of the fact that by its intervention science alters and refashions the object of investigation. In other words, method and object can no longer be separated.[60][61]
Shortly after the discovery of theneutron byJames Chadwick in 1932, Heisenberg submitted the first of three papers[62] on hisneutron-proton model of the nucleus.[36][63] AfterAdolf Hitler came to power in 1933, Heisenberg was attacked in the press as a "White Jew" (i.e. anAryan who acts like a Jew).[64] Supporters ofDeutsche Physik, or German Physics (also known as Aryan Physics), launched vicious attacks against leading theoretical physicists, including Arnold Sommerfeld and Heisenberg.[36] From the early 1930s onward, theanti-Semitic and anti-theoretical physics movementDeutsche Physik had concerned itself with quantum mechanics and thetheory of relativity. As applied in the university environment, political factors took priority over scholarly ability,[65] even though its two most prominent supporters were theNobel Laureates in PhysicsPhilipp Lenard[66] andJohannes Stark.[67][68]
There had been many failed attempts to have Heisenberg appointed as a professor at a number of German universities. His attempt to be appointed as successor to Arnold Sommerfeld failed because of opposition by theDeutsche Physik movement.[69] On 1 April 1935, the eminent theoretical physicist Sommerfeld, Heisenberg's doctoral advisor at theLudwig-Maximilians-Universität München, achievedemeritus status. However, Sommerfeld stayed in his chair during the selection process for his successor, which took until 1 December 1939. The process was lengthy due to academic and political differences between the Munich Faculty's selection and that of theReich Education Ministry and the supporters ofDeutsche Physik.
In 1935, the Munich Faculty drew up a list of candidates to replace Sommerfeld as ordinarius professor of theoretical physics and head of the Institute for Theoretical Physics at the University of Munich. The three candidates had all been former students of Sommerfeld: Heisenberg, who had received theNobel Prize in Physics;Peter Debye, who had received theNobel Prize in Chemistry in 1936; andRichard Becker. The Munich Faculty was firmly behind these candidates, with Heisenberg as their first choice. However, supporters ofDeutsche Physik and elements in the REM had their own list of candidates, and the battle dragged on for over four years. During this time, Heisenberg came under vicious attack by theDeutsche Physik supporters. One attack was published inDas Schwarze Korps, the newspaper of theSS, headed byHeinrich Himmler. In this, Heisenberg was called a "White Jew" who should be made to "disappear".[70] These attacks were taken seriously, as Jews were violently attacked and incarcerated. Heisenberg fought back with an editorial and a letter to Himmler, in an attempt to resolve the matter and regain his honour.
At one point, Heisenberg's mother visited Himmler's mother. The two women knew each other, as Heisenberg's maternal grandfather and Himmler's father were rectors and members of a Bavarian hiking club. Eventually, Himmler settled the Heisenberg affair by sending two letters, one to SSGruppenführerReinhard Heydrich and one to Heisenberg, both on 21 July 1938. In the letter to Heydrich, Himmler said Germany could not afford to lose or silence Heisenberg, as he would be useful for teaching a generation of scientists. To Heisenberg, Himmler said the letter came on the recommendation of his family and he cautioned Heisenberg to make a distinction between professional physics research results and the personal and political attitudes of the involved scientists.[71]
Wilhelm Müller replaced Sommerfeld at the Ludwig Maximilian University of Munich. Müller was not a theoretical physicist, had not published in a physics journal, and was not a member of theGerman Physical Society. His appointment was considered a travesty and detrimental to educating theoretical physicists.[71][72][73][74][75]
The three investigators who led the SS investigation of Heisenberg had training in physics. Indeed, Heisenberg had participated in the doctoral examination of one of them at theUniversität Leipzig. The most influential of the three wasJohannes Juilfs. During their investigation, they became supporters of Heisenberg as well as his position against the ideological policies of theDeutsche Physik movement in theoretical physics and academia.[76]
In mid-1936, Heisenberg presented his theory ofcosmic-ray showers in two papers.[77] Four more papers[78][79][80][81] appeared in the next two years.[36][82]
In December 1938, the German chemistsOtto Hahn andFritz Strassmann sent a manuscript toThe Natural Sciences reporting they had detected the elementbarium after bombardinguranium with neutrons, leading Hahn to conclude that abursting of the uranium nucleus had occurred;[83] simultaneously, Hahn communicated these results to his friendLise Meitner, who had in July of that year fled, first to the Netherlands, then to Sweden.[84] Meitner, and her nephewOtto Robert Frisch, correctly interpreted Hahn's and Strassmann's results as beingnuclear fission.[85] Frisch confirmed this experimentally on 13 January 1939.[86]
In June and July 1939, Heisenberg traveled to the United States visitingSamuel Abraham Goudsmit at theUniversity of Michigan inAnn Arbor. However, Heisenberg refused an invitation to emigrate to the United States. He did not see Goudsmit again until six years later, when Goudsmit was the chief scientific advisor to the AmericanOperation Alsos at the close of World War II.[36][87][88]
A visual representation of an induced nuclear fission event where a slow-moving neutron is absorbed by the nucleus of a uranium-235 atom, which fissions into two fast-moving lighter elements (fission products) and additional neutrons. Most of the energy released is in the form of the kinetic velocities of the fission products and the neutrons.
At a scientific conference on 26–28 February 1942 at the Kaiser Wilhelm Institute for Physics, called by the Army Weapons Office, Heisenberg presented a lecture to Reich officials on energy acquisition from nuclear fission.[93] The lecture, entitled "Die theoretischen Grundlagen für die Energiegewinnung aus der Uranspaltung" ("The theoretical basis for energy generation from uranium fission") was, as Heisenberg wrote after the Second World War in a letter toSamuel Goudsmit, "adapted to the intelligence level of a Reich Minister".[94] Heisenberg lectured on the enormous energy potential of nuclear fission, stating that 250 million electron volts could be released through the fission of an atomic nucleus. Heisenberg stressed that pure U-235 had to be obtained to achieve a chain reaction. He explored various ways of obtaining isotope235 92U in its pure form, including uranium enrichment and an alternative layered method of normal uranium and a moderator in a machine. This machine, he noted, could be used in practical ways to fuel vehicles, ships and submarines. Heisenberg stressed the importance of the Army Weapons Office's financial and material support for this scientific endeavour.
A second scientific conference followed. Lectures were heard on problems of modern physics with decisive importance for the national defense and economy. The conference was attended byBernhard Rust, the Reich Minister of Science, Education and National Culture. At the conference, Reich Minister Rust decided to take the nuclear project away from the Kaiser Wilhelm Society, and give it to the Reich Research Council.[95]
In April 1942 the army returned the Physics Institute to the Kaiser Wilhelm Society, naming Heisenberg as Director at the Institute.[69]Peter Debye was still director of the institute, but had gone on leave to the United States after he had refused to become a German citizen when the HWA took administrative control of the KWIP. Heisenberg still also had his department of physics at the University of Leipzig where work had been done for theUranverein byRobert Döpel and his wifeKlara Döpel.[36][92]
On 4 June 1942, Heisenberg was summoned to report toAlbert Speer, Germany's Minister of Armaments, on the prospects for converting the Uranverein's research toward developingnuclear weapons. During the meeting, Heisenberg told Speer that a bomb could not be built before 1945, because it would require significant monetary resources and number of personnel.[96][97]
After the Uranverein project was placed under the leadership of the Reich Research Council, it focused onnuclear power production and thus maintained itskriegswichtig (importance for the war) status; funding therefore continued from the military. The nuclear power project was broken down into the following main areas:uranium andheavy water production, uraniumisotope separation and theUranmaschine (uranium machine, i.e.,nuclear reactor). The project was then essentially split up between a number of institutes, where the directors dominated the research and set their own research agendas.[89][98][99] The point in 1942, when the army relinquished its control of the German nuclear weapons program, was the zenith of the project relative to the number of personnel. About 70 scientists worked for the program, with about 40 devoting more than half their time to nuclear fission research. After 1942, the number of scientists working on applied nuclear fission diminished dramatically. Many of the scientists not working with the main institutes stopped working on nuclear fission and devoted their efforts to more pressing war-related work.[100]
In September 1942, Heisenberg submitted his first paper of a three-part series on the scattering matrix, orS-matrix, in elementaryparticle physics. The first two papers were published in 1943[101][102] and the third in 1944.[103] The S-matrix described only the states of incident particles in a collision process, the states of those emerging from the collision, and stablebound states; there would be no reference to the intervening states. This was the same precedent as he followed in 1925 in what turned out to be the foundation of the matrix formulation of quantum mechanics through only the use of observables.[36][82]
In February 1943, Heisenberg was appointed to the Chair for Theoretical Physics at theFriedrich-Wilhelms-Universität (today, theHumboldt-Universität zu Berlin). In April, his election to thePreußische Akademie der Wissenschaften (Prussian Academy of Sciences) was approved. That same month, he moved his family to their retreat inUrfeld as Allied bombing increased in Berlin. In the summer, he dispatched the first of his staff at theKaiser-Wilhelm Institut für Physik toHechingen and its neighboring town ofHaigerloch, on the edge of theBlack Forest, for the same reasons. From 18–26 October, he travelled toGerman-occupied Netherlands. In December 1943, Heisenberg visitedGerman-occupied Poland.[36][104]
From 24 January to 4 February 1944, Heisenberg travelled to occupied Copenhagen, after the German army confiscatedBohr's Institute of Theoretical Physics. He made a short return trip in April. In December, Heisenberg lectured inneutral Switzerland.[36] The United StatesOffice of Strategic Services sent agentMoe Berg to attend the lecture carrying a pistol, with orders to shoot Heisenberg if his lecture indicated that Germany was close to completing an atomic bomb.[105]
In January 1945, Heisenberg, with most of the rest of his staff, moved from theKaiser-Wilhelm Institut für Physik to the facilities in the Black Forest.[36]
Replica of the German experimental nuclear reactor captured and dismantled at Haigerloch
The Alsos Mission was an Allied effort to determine whether the Germans had an atomic bomb program and to exploit German atomic-related facilities, research, material resources, and scientific personnel for the benefit of the US. Personnel on this operation generally swept into areas that had just come under control of the Allied military forces, but sometimes they operated in areas still under control by German forces.[106][107][108] Berlin had been a location of many German scientific research facilities. To limit casualties and loss of equipment, many of these facilities were dispersed to other locations in the latter years of the war. TheKaiser-Wilhelm-Institut für Physik (KWIP, Kaiser Wilhelm Institute for Physics) had been bombed so it had mostly been moved in 1943 and 1944 toHechingen and its neighbouring town ofHaigerloch, on the edge of theBlack Forest, which eventually became included in the French occupation zone. This allowed the American task force of the Alsos Mission to take into custody a large number of German scientists associated with nuclear research.[109][110]
On 30 March, the Alsos Mission reachedHeidelberg,[111] where important scientists were captured includingWalther Bothe,Richard Kuhn,Philipp Lenard, andWolfgang Gentner.[112] Their interrogation revealed that Otto Hahn was at his laboratory in Tailfingen, while Heisenberg andMax von Laue were at Heisenberg's laboratory inHechingen, and that the experimental natural uranium reactor that Heisenberg's team had built in Berlin had been moved to Haigerloch. Thereafter, the main focus of the Alsos Mission was on these nuclear facilities in theWürttemberg area.[41] Heisenberg was smuggled out from Urfeld, on 3 May 1945, in an alpine operation in territory still under control by elite German forces. He was taken to Heidelberg, where, on 5 May, he met Goudsmit for the first time since the Ann Arbor visit in 1939. Germany surrendered just two days later. Heisenberg would not see his family again for eight months, as he was moved across France and Belgium and flown to England on 3 July 1945.[113][114][107]
Nine of the prominent German scientists who published reports inNuclear Physics Research Reports as members of theUranverein[115] were captured by Operation Alsos and incarcerated in England underOperation Epsilon.[116] Ten German scientists, including Heisenberg, were held at Farm Hall in England. The facility had been asafe house of the British foreign intelligenceMI6. During their detention, their conversations were recorded. Conversations thought to be of intelligence value were transcribed and translated into English. The transcripts were released in 1992.[117][118] On 6 August 1945, the scientists at Farm Hall learned from media reports that the US had dropped an atomic bomb inHiroshima,Japan. At first, there was disbelief that a bomb had been built and dropped. In the weeks that followed, the German scientists discussed how the United States might have built the bomb.[119]
TheFarm Hall transcripts reveal that Heisenberg, along with other physicists interned at Farm Hall including Otto Hahn andCarl Friedrich von Weizsäcker, were glad the Allies had won World War II.[120] Heisenberg told other scientists that he had never contemplated a bomb, only an atomic pile to produce energy. The morality of creating a bomb for theNazis was also discussed. Only a few of the scientists expressed genuine horror at the prospect of nuclear weapons, and Heisenberg himself was cautious in discussing the matter.[121][122] On the failure of the German nuclear weapons program to build an atomic bomb, Heisenberg remarked, "We wouldn't have had the moral courage to recommend to the government in the spring of 1942 that they should employ 120,000 men just for building the thing up."[123]
When in 1992 the transcripts were declassified, German physicistManfred Popp analyzed the transcripts, as well as the documentation of Uranverein. When the German scientists heard about the Hiroshima bomb, Heisenberg admitted that he had never calculated the critical mass of an atomic bomb before. When he subsequently attempted to calculate the mass, he made serious calculation errors.Edward Teller andHans Bethe saw the transcript, and drew the conclusion that Heisenberg had done it for the first time as he made similar errors as they had. Only a week later Heisenberg gave a lecture about the physics of the bomb. He correctly recognized many essential aspects, including the efficiency of the bomb, although he still underestimated it. For Popp, this is proof that Heisenberg did not spend time on a nuclear weapon during the war; on the contrary, he avoided even thinking about it.[124][125]
Heisenberg together withHermann Rein [de] was instrumental in the establishment of theForschungsrat (research council). Heisenberg envisaged this council to promote the dialogue between the newly foundedFederal Republic of Germany and the scientific community, based in Germany.[127] Heisenberg was appointed president of theForschungsrat. In 1951, the organization was fused with theNotgemeinschaft der Deutschen Wissenschaft (Emergency Association of German Science) and that same year renamed theDeutsche Forschungsgemeinschaft (German Research Foundation). Following the merger, Heisenberg was appointed to the presidium.[36]
In 1951, Heisenberg agreed to become the scientific representative of theFederal Republic of Germany at theUNESCO conference, with the aim of establishing a European laboratory for nuclear physics. Heisenberg's aim was to build a largeparticle accelerator, drawing on the resources and technical skills of scientists across theWestern Bloc. On 1 July 1953 Heisenberg signed the convention that establishedCERN on behalf of the Federal Republic of Germany. Although he was asked to become CERN's founding scientific director, he declined. Instead, he was appointed chair of CERN's science policy committee and went on to determine the scientific program at CERN.[128]
In December 1953, Heisenberg became the president of theAlexander von Humboldt Foundation.[128] During his tenure as president 550 Humboldt scholars from 78 nations received scientific research grants. Heisenberg resigned as president shortly before his death.[129]
In 1946, the German scientistHeinz Pose, head of Laboratory V inObninsk, wrote a letter to Heisenberg inviting him to work in the USSR. The letter lauded the working conditions in the USSR and the available resources, as well as the favorable attitude of the Soviets towards German scientists. A courier hand delivered the recruitment letter, dated 18 July 1946, to Heisenberg; Heisenberg politely declined.[130][131] In 1947, Heisenberg presented lectures inCambridge,Edinburgh andBristol. Heisenberg contributed to the understanding of the phenomenon ofsuperconductivity with a paper in 1947[132] and two papers in 1948,[133][134] one of them withMax von Laue.[36][135]
In the period shortly after World War II, Heisenberg briefly returned to the subject of his doctoral thesis, turbulence. Three papers were published in 1948[136][137][138] and one in 1950.[18][139] In the post-war period Heisenberg continued his interests in cosmic-ray showers with considerations on multiple production ofmesons. He published three papers[140][141][142] in 1949, two[143][144] in 1952, and one[145] in 1955.[146]
In 1957, Heisenberg was a signatory of theGöttinger Manifest, taking a public stand against theFederal Republic of Germany arming itself withnuclear weapons. Heisenberg, likePascual Jordan, thought politicians would ignore this statement by nuclear scientists. But Heisenberg believed that the Göttinger Manifest would "influence public opinion" which politicians would have to take into account. He wrote toWalther Gerlach: "We will probably have to keep coming back to this question in public for a long time because of the danger that public opinion will slacken."[149] In 1961 Heisenberg signed theMemorandum of Tübingen alongside a group of scientists who had been brought together byCarl Friedrich von Weizsäcker andLudwig Raiser.[150] A public discussion between scientists and politicians ensued.[151] As prominent politicians, authors and socialites joined the debate on nuclear weapons, the signatories of the memorandum took a stand against "the full-time intellectual nonconformists".[152]
From 1957 onwards, Heisenberg was interested inplasma physics and the process ofnuclear fusion. He also collaborated with the International Institute of Atomic Physics inGeneva. He was a member of the Institute's scientific policy committee, and for several years was the Committee's chair.[3] He was one of the eight signatories of theMemorandum of Tübingen which called for the recognition of theOder–Neiße line as the official border betweenGermany andPoland and spoke against a possible nuclear armament ofWest Germany.[153]
In 1973, Heisenberg gave a lecture atHarvard University on the historical development of the concepts ofquantum theory.[154] On 24 March 1973 Heisenberg gave a speech before the Catholic Academy of Bavaria, accepting the Romano Guardini Prize. An English translation of his speech was published under the title "Scientific and Religious Truth", a quotation from which appears in a later section of this article.[155]
Heisenberg admiredEastern philosophy and saw parallels between it and quantum mechanics, describing himself as in "complete agreement" with the bookThe Tao of Physics. Heisenberg even went as far to state that after conversations withRabindranath Tagore aboutIndian philosophy "some of the ideas that seemed so crazy suddenly made much more sense".[156] Regarding thelaws of nature he remarked that "the concept of 'the law of nature' cannot be completely objective, the word 'law' being a purely human principle".[157]
Heisenberg, a devout Christian,[159][160] wrote: "We can console ourselves that the good Lord God would know the position of the [subatomic] particles, thus He would let the causality principle continue to have validity", in his last letter to Albert Einstein.[161] Einstein continued to maintain that quantum physics must be incomplete because it implies that the universe is indeterminate at a fundamental level.[162]
In lectures given in the 1950s and later published asPhysics and Philosophy, Heisenberg contended that scientific advances were leading to cultural conflicts. He stated that modern physics is "part of a general historical process that tends toward a unification and a widening of our present world".[163]
When Heisenberg accepted theRomano Guardini Prize [de] in 1974, he gave a speech, which he later published under the titleScientific and Religious Truth. He mused:
In the history of science, ever since the famoustrial of Galileo, it has repeatedly been claimed that scientific truth cannot be reconciled with the religious interpretation of the world. Although I am now convinced that scientific truth is unassailable in its own field, I have never found it possible to dismiss the content of religious thinking as simply part of an outmoded phase in the consciousness of mankind, a part we shall have to give up from now on. Thus in the course of my life I have repeatedly been compelled to ponder on the relationship of these two regions of thought, for I have never been able to doubt the reality of that to which they point.
Heisenberg referred to nature as "God's second book" (the first being the Bible) and believed that "Physics is reflection on the divineideas of Creation; therefore physics is divine service". This was because "God created the world in accordance with his ideas of creation" and humans can understand the world because "Man was created as the spiritual image of God".[165]
Heisenberg never participated in explicitNational Socialist propaganda. However, he fully supported Nazi Germany's project ofEuropean "renewal", which corresponded with his German-imperialist convictions.[166] The Dutch physicistHendrik Casimir recalled hearing from Heisenberg in 1943 that Germanworld domination was a historical necessity due to the weakness of Westernliberal democracy and the alternative ofSoviet Communism.[167] According to the British-German physicistRudolf Peierls, while visiting England in 1947 Heisenberg told a colleague who had been forced to emigrate from Germany that after another fifty years in power the Nazis "would have become quite decent".[168] The Austrian-Swedish physicistLise Meitner quoted Heisenberg's 1948 reply to being confronted with German atrocities: "Unfortunately, every spiritual upheaval has always been accompanied by great cruelty".[168]
Heisenberg, who did not leave Germany during the Nazi rule, was also unwilling to emigrate after the war. Responding to an offer of permanentendowed employment atYale University in 1951 conveyed byGregory Breit, he stated he would have considered it only ifWorld War III had broken out and theSoviet Union had occupied Göttingen.[169]
In his late sixties, Heisenberg penned his autobiography for the mass market. In 1969 the book was published in Germany, in early 1971 it was published in English and in the years thereafter in a string of other languages.[170] Heisenberg initiated the project in 1966, when his public lectures increasingly turned to the subjects of philosophy and religion. Heisenberg had sent the manuscript for a textbook on theunified field theory to Hirzel Verlag andJohn Wiley & Sons for publication. This manuscript, he wrote to one of his publishers, was the preparatory work for his autobiography. He structured his autobiography in themes, covering: 1) The goal of exact science, 2) The problematic of language in atomic physics, 3) Abstraction in mathematics and science, 4) The divisibility of matter or Kant's antinomy, 5) The basic symmetry and its substantiation, and 6) Science and religion.[171]
Heisenberg wrote his memoirs as a chain of conversations, covering the course of his life. The book became a popular success, but was regarded as troublesome by historians of science. In the preface Heisenberg wrote that he had abridged historical events, to make them more concise. At the time of publication, it was reviewed byPaul Forman in the journalScience with the comment "Now here is a memoir in the form of rationally reconstructed dialogue. And the dialogue as Galileo well knew, is itself a most insidious literary device: lively, entertaining, and especially suited for insinuating opinions while yet evading responsibility for them."[172] Few scientific memoirs had been published, butKonrad Lorenz andAdolf Portmann had penned popular books that conveyed scholarship to a wide audience. Heisenberg worked on his autobiography and published it with thePiper Verlag in Munich. Heisenberg initially proposed the titleGespräche im Umkreis der Atomphysik (Conversations on Atomic Physics). The autobiography was published eventually under the titleDer Teil und das Ganze (The Part and the Whole).[173] The 1971 English translation was published under the titlePhysics and Beyond: Encounters and Conversations.
The grave of the Heisenberg family inMunich Waldfriedhof, including August Heisenberg (1869–1930), Annie Heisenberg (1879–1945), Werner Heisenberg (1901–1976), and Elisabeth Heisenberg (1914–1998)
Heisenberg died of kidney cancer at his home, on 1 February 1976.[174] The next evening, his colleagues and friends walked in remembrance from the Institute of Physics to his home, lit a candle and placed it in front of his door.[175] Heisenberg is buried inMunich Waldfriedhof.[176]
In 1980 his widow,Elisabeth Heisenberg, publishedDas politische Leben eines Unpolitischen (The Political Life of an Apolitical Person), in which she characterized Heisenberg as "first and foremost, a spontaneous person, thereafter a brilliant scientist, next a highly talented artist, and only in the fourth place, from a sense of duty, homo politicus".[177]
1932 –Nobel Prize in Physics "for the creation of quantum mechanics, the application of which has,inter alia, led to the discovery of the allotropic forms of hydrogen".[58]
Werner HeisenbergDie Möglichkeit der technischer Energiegewinnung aus der Uranspaltung G-39 (6 December 1939)
Werner HeisenbergBericht über die Möglichkeit technischer Energiegewinnung aus der Uranspaltung (II) G-40 (29 February 1940)
Robert Döpel, K. Döpel, and Werner HeisenbergBestimmung der Diffusionslänge thermischer Neutronen in schwerem Wasser G-23 (7 August 1940)
Robert Döpel,K. Döpel, and Werner HeisenbergBestimmung der Diffusionslänge thermischer Neutronen in Präparat 38[184] G-22 (5 December 1940)
Robert Döpel, K. Döpel, and Werner HeisenbergVersuche mit Schichtenanordnungen von D2O und 38 G-75 (28 October 1941)
Werner HeisenbergÜber die Möglichkeit der Energieerzeugung mit Hilfe des Isotops 238 G-92 (1941)
Werner HeisenbergBericht über Versuche mit Schichtenanordnungen von Präparat 38 und Paraffin am Kaiser Wilhelm Institut für Physik in Berlin-Dahlem G-93 (May 1941)
Robert DöpelBericht über Unfälle beim Umgang mit Uranmetall G-135 (9 July 1942)
Werner HeisenbergBemerkungen zu dem geplanten halbtechnischen Versuch mit 1,5 to D2O und 3 to 38-Metall G-161 (31 July 1942)
Werner Heisenberg, Fritz Bopp, Erich Fischer,Carl-Friedrich von Weizsäcker, and Karl WirtzMessungen an Schichtenanordnungen aus 38-Metall und Paraffin G-162 (30 October 1942)
Robert Döpel, K. Döpel, and Werner HeisenbergDer experimentelle Nachweis der effektiven Neutronenvermehrung in einem Kugel-Schichten-System aus D2O und Uran-Metall G-136 (July 1942)
Werner HeisenbergDie Energiegewinnung aus der Atomkernspaltung G-217 (6 May 1943)
— (1934). "Bemerkungen zur Diracschen Theorie des Positrons".Zeitschrift für Physik.90 (3–4):209–231.Bibcode:1934ZPhy...90..209H.doi:10.1007/BF01333516.S2CID186232913. The author was cited as being at Leipzig. The paper was received on 21 June 1934.
— (1936). "Über die 'Schauer' in der Kosmischen Strahlung".Forsch. Fortscher.12:341–342.
—; Euler, H. (1936). "Folgerungen aus der Diracschen Theorie des Positrons".Z. Phys.98 (11–12):714–732.Bibcode:1936ZPhy...98..714H.doi:10.1007/BF01343663.S2CID120354480. The authors were cited as being at Leipzig. The paper was received on 22 December 1935. A translation of this paper has been done by W. Korolevski and H. Kleinert:arXiv:physics/0605038v1.
— (1938). "Der Durchgang sehr energiereicher Korpuskeln durch den Atomkern".Nuovo Cimento.15 (1):31–34.Bibcode:1938NCim...15...31H.doi:10.1007/BF02958314.S2CID123209538.— (1938). "Der Durchgang sehr energiereicher Korpuskeln durch den Atomkern".Verh. Dtsch. Phys. Ges.19 (2).
— (1975). "Development of concepts in the history of quantum theory".American Journal of Physics.43 (5):389–394.Bibcode:1975AmJPh..43..389H.doi:10.1119/1.9833. The substance of this article was presented by Heisenberg in a lecture at Harvard University.
Heisenberg's surname is used as the primaryalias forWalter White (played byBryan Cranston), the lead character inAMC's crime drama seriesBreaking Bad, throughout White's transformation from a high-school chemistry teacher into ameth cook and a drug kingpin.[185] In the spin-off prequel seriesBetter Call Saul, a German character named Werner directs the construction of the meth lab belonging to antagonistGus Fring that Walt cooks in for much ofBreaking Bad.[186]
The 2015 TV filmKampen om Tungtvannet (The Heavy Water War: Stopping Hitler's Atomic Bomb)[187] directed by Per-Olav Sørensen, extensively features Werner Heisenberg and his career, including his nuclear research under the Nazis.
Heisenberg is the namesake ofResident Evil Village secondary antagonist Karl Heisenberg. Heisenberg's research on ferromagnetism served as inspiration for the character's magnetic abilities.
In the television seriesStar Trek: The Next Generation, the "Heisenberg compensator" is an essential component oftransporter technology to ensure the integrity of transported matter. The compensator counteracts effects of the applied characteristics identified in Heisenberg's uncertainty principle. To accurately isolate matter prior to its entry into the transporter buffer, all particles must be located, their velocity observed, and tracked; the compensators allow this to happen.
^Kursunoglu, Behram N.; Wigner, Eugene P. (26 April 1990).Paul Adrien Maurice Dirac: Reminiscences about a Great Physicist. Cambridge University Press. p. 132.ISBN978-0-521-38688-3.
^Heisenberg, W. (1925). "Über quantentheoretishe Umdeutung kinematisher und mechanischer Beziehungen".Zeitschrift für Physik.33 (1):879–893.Bibcode:1925ZPhy...33..879H.doi:10.1007/BF01328377.S2CID186238950. (received 29 July 1925). [English translation in: B.L. van der Waerden, editor,Sources of Quantum Mechanics (Dover Publications, 1968)ISBN978-0-486-61881-4 (English title: "Quantum-Theoretical Re-interpretation of Kinematic and Mechanical Relations").]
^MacKinnon, Edward (1977). "Heisenberg, Models, and the Rise of Quantum Mechanics".Historical Studies in the Physical Sciences.8:137–188.doi:10.2307/27757370.JSTOR27757370.
^abcSmolin, Lee (9 April 2019).Einstein's unfinished revolution: the search for what lies beyond the quantum. London: Allen Lane. pp. 92–93.ISBN978-0-241-00448-7.OCLC1048948576.
^Heisenberg, W. (1938)Der Durchgang sehr energiereicher Korpuskeln durch den Atomkern,Nuovo Cimento Volume 15, 31–34;Verh. Dtsch. Phys. Ges. Volume 19, 2, as cited byMott & Peierls 1977, p. 244
^Hahn, O.; Strassmann, F. (1939). "Über den Nachweis und das Verhalten der bei der Bestrahlung des Urans mittels Neutronen entstehenden Erdalkalimetalle" [On the detection and characteristics of the alkaline earth metals formed by irradiation of uranium with neutrons].Naturwissenschaften.27 (1):11–15.Bibcode:1939NW.....27...11H.doi:10.1007/BF01488241.S2CID5920336.. The authors were identified as being at theKaiser-Wilhelm-Institut für Chemie, Berlin-Dahlem. Received 22 December 1938.
^Meitner, Lise (11 February 1939). "Disintegration of Uranium by Neutrons: a New Type of Nuclear Reaction".Nature.143 (3615):239–240.Bibcode:1939Natur.143..239M.doi:10.1038/143239a0.S2CID4113262. The paper is dated 16 January 1939. Meitner is identified as being at the Physical Institute, Academy of Sciences, Stockholm. Frisch is identified as being at the Institute of Theoretical Physics, University of Copenhagen.
^Hentschel & Hentschel 1996, pp. 363–364, Appendix F, see the entries for Diebner and Döpel. See also the entry for the KWIP in Appendix A and the entry for the HWA in Appendix B.
^Hentschel & Hentschel 1996; see the entry for the KWIP in Appendix A and the entries for the HWA and the RFR in Appendix B. Also see p. 372 and footnote #50 on p. 372.
^Mahoney, Leo J. (1981).A History of the War Department Scientific Intelligence Mission (ALSOS), 1943–1945 (PhD thesis). Kent State University. p. 298.OCLC223804966.
^abGerd W. Buschhorn; Julius Wess, eds. (2012).Fundamental Physics – Heisenberg and Beyond: Werner Heisenberg Centennial Symposium "Developments in Modern Physics". Springer Science & Business Media. p. 18.ISBN978-3-642-18623-3.
^abGerd W. Buschhorn; Julius Wess, eds. (2012).Fundamental Physics – Heisenberg and Beyond: Werner Heisenberg Centennial Symposium "Developments in Modern Physics". Springer Science & Business Media. p. 21.ISBN978-3-642-18623-3.
^Gerd W. Buschhorn; Julius Wess, eds. (2012).Fundamental Physics – Heisenberg and Beyond: Werner Heisenberg Centennial Symposium "Developments in Modern Physics". Springer Science & Business Media. p. 22.ISBN978-3-642-18623-3.
^Heisenberg, w. (1950). "On the stability of laminar flow".Proc. International Congress Mathematicians.II:292–296., as cited inMott & Peierls 1977, p. 245
^Horst KantWerner Heisenberg and the German Uranium Project / Otto Hahn and the Declarations of Mainau and Göttingen, Preprint 203 (Max-Planck Institut für Wissenschaftsgeschichte,2002Archived 5 February 2012 at theWayback Machine).
^Dönhoff, Marion (2 March 1962)."Lobbyisten der Vernunft" [Lobbyists of reason].Die Zeit (in German).Archived from the original on 18 November 2018. Retrieved17 November 2018.
^Heisenberg, Werner (1975). "Development of concepts in the history of quantum theory".American Journal of Physics.43 (5):389–394.Bibcode:1975AmJPh..43..389H.doi:10.1119/1.9833.
^abHeizenberg, W. (1974). "Ch. 16 "Scientific and Religious Truth"".Across the Frontiers. Harper & Row. pp. 213–229.
^Moore, Lance (2019).A God Beyond Belief: Reclaiming Faith in a Quantum Age. John Hunt Publishing, UK
^Marganau, Henry (1985). "Why am I a Christian".Truth Journal, Vol. I
^Holton, Gerald (2005).Victory and Vexation in Science: Einstein, Bohr, Heisenberg and Others. Harvard University Press, London. p. 32.ISBN978-0-674-01519-7
^Werner Heisenberg (1970) "Erste Gespräche über das Verhältnis von Naturwissenschaft und Religion" in ed. Werner Trutwin, "Religion-Wissenschaft-Weltbild" Duesseldorf: Patmos Verlag, pages 23–31
^Gerd W. Buschhorn; Julius Wess, eds. (2012).Fundamental Physics – Heisenberg and Beyond: Werner Heisenberg Centennial Symposium "Developments in Modern Physics". Springer Science & Business Media. p. 16.ISBN978-3-642-18623-3.
Heisenberg, W. (1934). "Bemerkungen zur Diracschen Theorie des Positrons".Zeitschrift für Physik.90 (3–4):209–231.Bibcode:1934ZPhy...90..209H.doi:10.1007/BF01333516.S2CID186232913. The author was cited as being at Leipzig. The paper was received on 21 June 1934.
Heisenberg, W. (1936a). "Über die 'Schauer' in der Kosmischen Strahlung".Forsch. Fortscher.12:341–342.
Heisenberg, W.; Euler, H. (1936). "Folgerungen aus der Diracschen Theorie des Positrons".Z. Phys.98 (11–12):714–732.Bibcode:1936ZPhy...98..714H.doi:10.1007/BF01343663.S2CID120354480. The authors were cited as being at Leipzig. The paper was received on 22 December 1935. A translation of this paper has been done by W. Korolevski and H. Kleinert:arXiv:physics/0605038v1.
Macrakis, Kristie (1993).Surviving the Swastika: Scientific Research in Nazi Germany. Oxford University Press.ISBN978-0-19-507010-1.
Mott, N.; Peierls, R. (November 1977). "Werner Heisenberg".Biographical Memoirs of Fellows of the Royal Society.23:213–251.doi:10.1098/rsbm.1977.0009.S2CID73128582.
Rose, Paul Lawrence (2002).Heisenberg and the Nazi Atomic Bomb Project: A Study in German Culture. University of California Press.ISBN978-0-520-22926-6.
