In April 1945 Soviet troops reached Berlin, the Reich collapsed and the Russians began sending to the Soviet Union the remaining apparatus in the Dahlem institute, the institute library, and the several German scientists they found there (among them Ludwig Bewilogua who had built the low temperature laboratory and had run the high voltage generator during the war). The Berlin KWI für Physik ceased to exist, while the Hechingen division barely survived with a handful of scientists – including Fritz Bopp, the crystallographer Georg Menzer and the spectroscopist Hermann Schüler – and a handful of experiments unrelated to nuclear physics.
Heisenberg was held along with the other prominent members of the Uranium Club at the country estate Farm Hall near Cambridge, England, well treated and equally well watched. During their stay at Farm Hall the atomic bomb was dropped on the Japanese city of Hiroshima on 6 August 1945. From news reports the German scientists learned that the Allies had, in their efforts to gain energy from atomic fission, obviously progressed much further than the Germans and had achieved military uses, an application that the Germans had believed to lie only far in the future. Their many discussions about the consequences of military applications of nuclear energy contributed to their later stance against nuclear weapons for the German Army.
At Farm Hall Heisenberg also set the stage for his future research. After years of difficulty, political pressure and reduced exchange of ideas he took the opportunity to devote himself in leisure to a wide range of physical problems. Included were the still unresolved problems of explaining superconductivity, which he discussed with von Laue, and the application of statistical methods to the description of turbulence, discussed with von Weizsäcker. He also decided to remain in Germany, despite lucrative offers to come to the United States and to work at the KWI für Physik if that would become possible.
On 3 January 1946, the German scientists were released from Farm Hall and returned to Western Germany. Heisenberg went with Hahn, von Laue, von Weizsäcker and Wirtz to Göttingen in the British Occupation Zone, where Max Planck and Ernst Telschow were seeking to continue the Kaiser Wilhelm Society and its institutes. Heisenberg devoted himself upon his return to two large tasks: the reconstruction of the KWI für Physik as a center for experimental and theoretical research in physics and the renewal of research in Germany. In particular he pondered a suitable vehicle for mediating between scientific research and the future German government in order to insure technical prosperity and the protection of science as the source of technical progress.
During the immediate post-war years Germans had to rebuild practically from the ground up. With the collapse of economic and political organization and the division of Germany into four occupation zones, the reconstruction of research in Germany was extremely difficult. The conditions were perhaps most favorable in the British Zone, where the authorities, especially the liaison officer Colonel Bertie Blount, appeared quite open to the needs of the German scientists. As early as 1 January 1946 scientists and officials formed the German Scientific Council (Deutscher Wissenschaftlicher Rat) under the chairmanship of the Nobel Prize chemist Adolf Windaus. It mediated between the British military government and German scientific institutes and enabled, among other activities, the rebuilding of the Physico-Technical-Institute (Physikalisch-Technische Reichsanstalt) in Braunschweig and the refounding of the German Physical Society (Deutsche Physikalische Gesellschaft) within the British Zone. The old British Hanoverian university city of Göttingen, largely untouched by the war, became once again a scientific center. During a meeting with Göttingen scientists in October 1946 the British authorities permitted the installation in Göttingen of several Kaiser Wilhelm institutes on the grounds of the former Aerodynamical Research Institute (Aerodynamische Versuchsanstalt) which had been completely dismantled as war-related. The institutes for physics, physical chemistry and medical research, previously all in Berlin, were thus revived. Finally the Kaiser Wilhelm Society was renamed and reinstituted in the three western zones as the Max Planck Society with seat in Göttingen; after 16 February 1948 all its institutes in western Germany were renamed Max Planck institutes (MPI).
In July 1946 Heisenberg began reequipping the institute for physics, whose direction he assumed after the official director Debye declined an offer to return. Two departments were set up initially: one for theoretical physics under von Weizsäcker, the other for experimental physics under Wirtz. Research was limited by the directives of the Allied Control Commission in that Germans were forbidden to work in a variety of fields considered war related, especially areas of nuclear physics involving slow neutrons and nuclear fission. Despite the limitations Heisenberg and his colleagues, many of whom had worked with him earlier in Berlin, did not lack research topics. Foremost remained the study of cosmic-ray physics, begun in Leipzig, continued in Berlin, and now picked up once again in Göttingen. Most of the institute resources were directed at first into theoretical research, since financing did not suffice for experimental studies. Only gradually did the institute catch up with the rapid developments occurring elsewhere in cosmic-ray and elementary particle physics at that time. The second edition of Kosmische Strahlung, published in 1953, indicated a near approximation to international standards in this subject. During the early post-war years Heisenberg also presented a theory of superconductivity (1946-1948), a statistical theory of turbulence (1946-1948), and examined the theoretical properties of elementary particles (after 1946).
Besides the direction of his institute and his own research Heisenberg devoted himself with great energy to the revival of scientific research in Western Germany and especially to his conception of governmental science policy. Learning from his experiences in the Third Reich, his observations of the close cooperation between scientists and government in Great Britain, and believing that a modern industrial state required a central science policy, Heisenberg sought a direct role for the government of the new Federal Republic of Germany in forming a national policy of support for science and technology and a role for science advisors to the chancellor. Such conceptions found expression in the German Research Council (Deutschen Forschungsrat) founded on 9 March 1949 by the Max Planck Society and the surviving academies of science in West Germany. It was composed of 15 leading scientists with Heisenberg as president. The new council, supported by Chancellor Konrad Adenauer, represented Ger man science in international affairs and directly in the chancellor's office. Among its successes were the acquisition of Marshall Plan money for the support of German research, the admission of the Federal Republic to the International Union of Scientific Councils and to UNESCO, the provision of federal responsibility for science in the West German constitution, and the assurance of mutual support between German industry and science. Yet the institution of the German Research Council contradicted the long tradition in Germany that science fell under the authority of the cultural ministers of each state (Land). Hence the council was challenged increasingly by the Emergency Association of German Science (Notgemeinschaft der Deutschen Wissenschaft), revived in January 1949 by the ministers of culture and the university rectors. To avoid rivalry and the damaging overlap of interests, Heisenberg, with much regret, gave up his idea of a federal science body. The two bodies, e.i. the Research Council and the Emergency Association, were joined into the present-day German Research Association (Deutsche Forschungsgemeinschaft) in August 1951. The task of representing German science was assumed by the senate of the new body composed mainly of members of the former Research Council. Heisenberg was elected to the presidential committee of the new Research Association; he also directed after February 1952 its Commission for Atomic Physics (Kommission für Atomphysik) which coordinated nuclear research (with the exception of research in nuclear fission) nationwide.
Heisenberg's constant involvement in German science policy found its counterpart in his involvement in the organization of research in his own institute. On.1 July 1947 a new astro-physical department was added under the direction of Ludwig Biermann, who had earlier worked at the Babelsberg observatory and the University of Hamburg. Biermann and his collaborators concentrated in Göttingen on cosmic plasma physics and on quantum theoretical problems in astrophysics. They soon attained significant results, in particular the prediction of the so-called “solar wind” from an analysis of the behavior of comet tails (Biermann and Rhea Lüst) and a new formation of the basic equations of plasma physics (Arnulf Schlüter). Their work required, as did other topics treated at Heisenberg's institute, the increased application of electronic data handling. Since such tools were not available at that time in Germany, the Max Planck Society began its own development program. Heinrich Billing, since 1 June 1950 head of the computer group at the Institute for Instrument Studies (Institut für Instrumentenkunde) in Göttingen and after 1957 a member of the MPI für Physik developed and constructed the programmed calculating machines Gl and G2; the former was used after October 1952 at the MPI in Göttingen. Billing's breakthroughs in computer technology were unfortunately not realized by German industry.
The work produced by the Göttingen MPI during the years of reconstruction won a growing international reputation, and the institute's director Heisenberg attained increasing recognition as the leading representative of German science in the international arena. The reestablishment of international relations, also of great importance to Heisenberg, began officially, with his invitation to lecture at the British universities in Cambridge, Edinburgh and Bristol in December 1947. During the following years he repeatedly visited Niels Bohr in Copenhagen and in summer 1950 he participated in the International Congress of Mathematicians in Cambridge, Massachusetts (30 August – 6 September). In 1954, on a travel to the US, he visited Einstein in Princeton and discussed quantum mechanics with him. He also served as the West German delegate to the conference on Atoms for Peace in Geneva. When in 1952 the European Council for Nuclear Research came into being, Heisenberg headed the German delegation and participated in the decision to locate the large European research center for high energy physics, CERN, in Geneva, Switzerland. The Scientific Policy Committee of CERN, responsible for planning the research program, elected Heisenberg as its chairman.
Immediately after his return to post-war Germany Heisenberg emphasized in a programmatic speech before Göttingen students the role of “science as a tool of mutual understanding between peoples” (13 July 1946). He plunged into the task of getting German scientists reaccepted as members of the international family of scientists and of renewing personal relations after the isolation and alienation in the previous period of the Third Reich and World War II. In this endeavor he assigned a particularly important role to the reestablished Alexander von Humboldt Foundation, whose first president he was appointed on 10 December 1953 by Chancellor Adenauer. The purpose of the foundation is to enable young scholars and scientists from around the world to collaborate with German colleagues while guests at German research institutes. Numerous Humboldt fellows were invited to Heisenberg's institute in Göttingen and later in Munich. He held the president's office until a severe illness forced him to resign in October 1975.
On 5 May 1955 the Paris Accords came into effect, whereby the Western A1lies granted the Federal Republic full sovereignty and full membership in the NATO alliance. All restrictions on West German research were thus removed and, after ten years of restraint, the development of German nuclear energy resumed in full. In October 1955 Adenauer created a Federal Ministry for Atomic Questions (Bundesministerium für Atomfragen), forerunner of the wider ranged, present-day Ministry for Research and Technology (Bundesministerium für Forschung und Technologie). Heisenberg served as a leading member of the German Atomic Commission (Deutsche Atomkommission) set up by the new ministry and composed of scientists, industrialists, and politicians with the purpose of advising the ministry on nuclear energy policy. Heisenberg also directed the committee on nuclear physics within the Atomic Commission, served as a member of the Bavarian Atomic Commission, and acted as the main impetus toward the construction of Germany's first nuclear reactor, a research model set up at Garching near Munich in October 1957.
While Heisenberg supported the development of nuclear energy for peaceful uses, he and other scientists equally energetically opposed the plans of Chancellor Adenauer to equip the West German army with tactical nuclear weapons. Adenauer met with stiff resistance from Hahn, Heisenberg, von Weizsäcker and other atomic scientists, eighteen of whom issued a public declaration (basically formulated by von Weizsäcker and Heisenberg) from Göttingen on 12 April 1957, opposing research on or possession of nuclear weapons by West Germany. The West German army has since remained non-nuclear.
Heisenberg's main scientific interest in the early fifties increasingly focused on the search for a consistent quantum field theory of elementary particles. After an unsuccessful attempt at obtaining a nonlocal theory, he became concerned after 1952 with the investigation of nonlinear field equations, in which the mathematical space of states was extended beyond that used since the early days of quantum mechanics. In this theory, which Heisenberg and his collaborators developed in a series of papers between November 1953 and December 1956, the conditions of relativistic invariance could be immediately introduced and finite results could always be obtained without the use of supplementary subtraction or normalization procedures. After Heisenberg had demonstrated the consistency of his ideas and methods in case of a model field theory, the so-called Lee model (October 1957), he entered into a close collaboration with Pauli that yielded in early 1958 the proposal of a nonlinear spinor equation designed to describe the properties and the behavior of all known elementary particles (dubbed the “world formula” by eager journalists). While Heisenberg expounded the equation in April 1958 and on several later occasions, Pauli withdrew his support.
Heisenberg's efforts to obtain a consistent quantum field theory for all elementary particles harmonized with the philosophical views that he presented at that time in many public lectures and lecture series (e.g., in the Gifford Lectures delivered in the winter term 1955/56 at St. Andrew's University in Scotland).
In September 1958 Heisenberg's MPI für Physik moved from Göttingen into a large new building in Munich near the English Garden, which solved the problem of overcrowding at the old institute. Differing from original plans, Karl Wirtz and his reactor group did not move to Munich, but left the MPI in March 1957 and settled at the nuclear research center of theKernreaktor Bau- und Betriebsgesellchaft mbH. close to Karlsruhe. C.F. von Weizsäcker did not, go to Munich either, as he accepted in June 1957 a call to a philosophy chair at the University of Hamburg. Yet he remained a regular guest in the Munich MPI during his semester vacations.
Heisenberg was held along with the other prominent members of the Uranium Club at the country estate Farm Hall near Cambridge, England, well treated and equally well watched. During their stay at Farm Hall the atomic bomb was dropped on the Japanese city of Hiroshima on 6 August 1945. From news reports the German scientists learned that the Allies had, in their efforts to gain energy from atomic fission, obviously progressed much further than the Germans and had achieved military uses, an application that the Germans had believed to lie only far in the future. Their many discussions about the consequences of military applications of nuclear energy contributed to their later stance against nuclear weapons for the German Army.
At Farm Hall Heisenberg also set the stage for his future research. After years of difficulty, political pressure and reduced exchange of ideas he took the opportunity to devote himself in leisure to a wide range of physical problems. Included were the still unresolved problems of explaining superconductivity, which he discussed with von Laue, and the application of statistical methods to the description of turbulence, discussed with von Weizsäcker. He also decided to remain in Germany, despite lucrative offers to come to the United States and to work at the KWI für Physik if that would become possible.
On 3 January 1946, the German scientists were released from Farm Hall and returned to Western Germany. Heisenberg went with Hahn, von Laue, von Weizsäcker and Wirtz to Göttingen in the British Occupation Zone, where Max Planck and Ernst Telschow were seeking to continue the Kaiser Wilhelm Society and its institutes. Heisenberg devoted himself upon his return to two large tasks: the reconstruction of the KWI für Physik as a center for experimental and theoretical research in physics and the renewal of research in Germany. In particular he pondered a suitable vehicle for mediating between scientific research and the future German government in order to insure technical prosperity and the protection of science as the source of technical progress.
During the immediate post-war years Germans had to rebuild practically from the ground up. With the collapse of economic and political organization and the division of Germany into four occupation zones, the reconstruction of research in Germany was extremely difficult. The conditions were perhaps most favorable in the British Zone, where the authorities, especially the liaison officer Colonel Bertie Blount, appeared quite open to the needs of the German scientists. As early as 1 January 1946 scientists and officials formed the German Scientific Council (Deutscher Wissenschaftlicher Rat) under the chairmanship of the Nobel Prize chemist Adolf Windaus. It mediated between the British military government and German scientific institutes and enabled, among other activities, the rebuilding of the Physico-Technical-Institute (Physikalisch-Technische Reichsanstalt) in Braunschweig and the refounding of the German Physical Society (Deutsche Physikalische Gesellschaft) within the British Zone. The old British Hanoverian university city of Göttingen, largely untouched by the war, became once again a scientific center. During a meeting with Göttingen scientists in October 1946 the British authorities permitted the installation in Göttingen of several Kaiser Wilhelm institutes on the grounds of the former Aerodynamical Research Institute (Aerodynamische Versuchsanstalt) which had been completely dismantled as war-related. The institutes for physics, physical chemistry and medical research, previously all in Berlin, were thus revived. Finally the Kaiser Wilhelm Society was renamed and reinstituted in the three western zones as the Max Planck Society with seat in Göttingen; after 16 February 1948 all its institutes in western Germany were renamed Max Planck institutes (MPI).
In July 1946 Heisenberg began reequipping the institute for physics, whose direction he assumed after the official director Debye declined an offer to return. Two departments were set up initially: one for theoretical physics under von Weizsäcker, the other for experimental physics under Wirtz. Research was limited by the directives of the Allied Control Commission in that Germans were forbidden to work in a variety of fields considered war related, especially areas of nuclear physics involving slow neutrons and nuclear fission. Despite the limitations Heisenberg and his colleagues, many of whom had worked with him earlier in Berlin, did not lack research topics. Foremost remained the study of cosmic-ray physics, begun in Leipzig, continued in Berlin, and now picked up once again in Göttingen. Most of the institute resources were directed at first into theoretical research, since financing did not suffice for experimental studies. Only gradually did the institute catch up with the rapid developments occurring elsewhere in cosmic-ray and elementary particle physics at that time. The second edition of Kosmische Strahlung, published in 1953, indicated a near approximation to international standards in this subject. During the early post-war years Heisenberg also presented a theory of superconductivity (1946-1948), a statistical theory of turbulence (1946-1948), and examined the theoretical properties of elementary particles (after 1946).
Besides the direction of his institute and his own research Heisenberg devoted himself with great energy to the revival of scientific research in Western Germany and especially to his conception of governmental science policy. Learning from his experiences in the Third Reich, his observations of the close cooperation between scientists and government in Great Britain, and believing that a modern industrial state required a central science policy, Heisenberg sought a direct role for the government of the new Federal Republic of Germany in forming a national policy of support for science and technology and a role for science advisors to the chancellor. Such conceptions found expression in the German Research Council (Deutschen Forschungsrat) founded on 9 March 1949 by the Max Planck Society and the surviving academies of science in West Germany. It was composed of 15 leading scientists with Heisenberg as president. The new council, supported by Chancellor Konrad Adenauer, represented Ger man science in international affairs and directly in the chancellor's office. Among its successes were the acquisition of Marshall Plan money for the support of German research, the admission of the Federal Republic to the International Union of Scientific Councils and to UNESCO, the provision of federal responsibility for science in the West German constitution, and the assurance of mutual support between German industry and science. Yet the institution of the German Research Council contradicted the long tradition in Germany that science fell under the authority of the cultural ministers of each state (Land). Hence the council was challenged increasingly by the Emergency Association of German Science (Notgemeinschaft der Deutschen Wissenschaft), revived in January 1949 by the ministers of culture and the university rectors. To avoid rivalry and the damaging overlap of interests, Heisenberg, with much regret, gave up his idea of a federal science body. The two bodies, e.i. the Research Council and the Emergency Association, were joined into the present-day German Research Association (Deutsche Forschungsgemeinschaft) in August 1951. The task of representing German science was assumed by the senate of the new body composed mainly of members of the former Research Council. Heisenberg was elected to the presidential committee of the new Research Association; he also directed after February 1952 its Commission for Atomic Physics (Kommission für Atomphysik) which coordinated nuclear research (with the exception of research in nuclear fission) nationwide.
Heisenberg's constant involvement in German science policy found its counterpart in his involvement in the organization of research in his own institute. On.1 July 1947 a new astro-physical department was added under the direction of Ludwig Biermann, who had earlier worked at the Babelsberg observatory and the University of Hamburg. Biermann and his collaborators concentrated in Göttingen on cosmic plasma physics and on quantum theoretical problems in astrophysics. They soon attained significant results, in particular the prediction of the so-called “solar wind” from an analysis of the behavior of comet tails (Biermann and Rhea Lüst) and a new formation of the basic equations of plasma physics (Arnulf Schlüter). Their work required, as did other topics treated at Heisenberg's institute, the increased application of electronic data handling. Since such tools were not available at that time in Germany, the Max Planck Society began its own development program. Heinrich Billing, since 1 June 1950 head of the computer group at the Institute for Instrument Studies (Institut für Instrumentenkunde) in Göttingen and after 1957 a member of the MPI für Physik developed and constructed the programmed calculating machines Gl and G2; the former was used after October 1952 at the MPI in Göttingen. Billing's breakthroughs in computer technology were unfortunately not realized by German industry.
The work produced by the Göttingen MPI during the years of reconstruction won a growing international reputation, and the institute's director Heisenberg attained increasing recognition as the leading representative of German science in the international arena. The reestablishment of international relations, also of great importance to Heisenberg, began officially, with his invitation to lecture at the British universities in Cambridge, Edinburgh and Bristol in December 1947. During the following years he repeatedly visited Niels Bohr in Copenhagen and in summer 1950 he participated in the International Congress of Mathematicians in Cambridge, Massachusetts (30 August – 6 September). In 1954, on a travel to the US, he visited Einstein in Princeton and discussed quantum mechanics with him. He also served as the West German delegate to the conference on Atoms for Peace in Geneva. When in 1952 the European Council for Nuclear Research came into being, Heisenberg headed the German delegation and participated in the decision to locate the large European research center for high energy physics, CERN, in Geneva, Switzerland. The Scientific Policy Committee of CERN, responsible for planning the research program, elected Heisenberg as its chairman.
Immediately after his return to post-war Germany Heisenberg emphasized in a programmatic speech before Göttingen students the role of “science as a tool of mutual understanding between peoples” (13 July 1946). He plunged into the task of getting German scientists reaccepted as members of the international family of scientists and of renewing personal relations after the isolation and alienation in the previous period of the Third Reich and World War II. In this endeavor he assigned a particularly important role to the reestablished Alexander von Humboldt Foundation, whose first president he was appointed on 10 December 1953 by Chancellor Adenauer. The purpose of the foundation is to enable young scholars and scientists from around the world to collaborate with German colleagues while guests at German research institutes. Numerous Humboldt fellows were invited to Heisenberg's institute in Göttingen and later in Munich. He held the president's office until a severe illness forced him to resign in October 1975.
On 5 May 1955 the Paris Accords came into effect, whereby the Western A1lies granted the Federal Republic full sovereignty and full membership in the NATO alliance. All restrictions on West German research were thus removed and, after ten years of restraint, the development of German nuclear energy resumed in full. In October 1955 Adenauer created a Federal Ministry for Atomic Questions (Bundesministerium für Atomfragen), forerunner of the wider ranged, present-day Ministry for Research and Technology (Bundesministerium für Forschung und Technologie). Heisenberg served as a leading member of the German Atomic Commission (Deutsche Atomkommission) set up by the new ministry and composed of scientists, industrialists, and politicians with the purpose of advising the ministry on nuclear energy policy. Heisenberg also directed the committee on nuclear physics within the Atomic Commission, served as a member of the Bavarian Atomic Commission, and acted as the main impetus toward the construction of Germany's first nuclear reactor, a research model set up at Garching near Munich in October 1957.
While Heisenberg supported the development of nuclear energy for peaceful uses, he and other scientists equally energetically opposed the plans of Chancellor Adenauer to equip the West German army with tactical nuclear weapons. Adenauer met with stiff resistance from Hahn, Heisenberg, von Weizsäcker and other atomic scientists, eighteen of whom issued a public declaration (basically formulated by von Weizsäcker and Heisenberg) from Göttingen on 12 April 1957, opposing research on or possession of nuclear weapons by West Germany. The West German army has since remained non-nuclear.
Heisenberg's main scientific interest in the early fifties increasingly focused on the search for a consistent quantum field theory of elementary particles. After an unsuccessful attempt at obtaining a nonlocal theory, he became concerned after 1952 with the investigation of nonlinear field equations, in which the mathematical space of states was extended beyond that used since the early days of quantum mechanics. In this theory, which Heisenberg and his collaborators developed in a series of papers between November 1953 and December 1956, the conditions of relativistic invariance could be immediately introduced and finite results could always be obtained without the use of supplementary subtraction or normalization procedures. After Heisenberg had demonstrated the consistency of his ideas and methods in case of a model field theory, the so-called Lee model (October 1957), he entered into a close collaboration with Pauli that yielded in early 1958 the proposal of a nonlinear spinor equation designed to describe the properties and the behavior of all known elementary particles (dubbed the “world formula” by eager journalists). While Heisenberg expounded the equation in April 1958 and on several later occasions, Pauli withdrew his support.
Heisenberg's efforts to obtain a consistent quantum field theory for all elementary particles harmonized with the philosophical views that he presented at that time in many public lectures and lecture series (e.g., in the Gifford Lectures delivered in the winter term 1955/56 at St. Andrew's University in Scotland).
In September 1958 Heisenberg's MPI für Physik moved from Göttingen into a large new building in Munich near the English Garden, which solved the problem of overcrowding at the old institute. Differing from original plans, Karl Wirtz and his reactor group did not move to Munich, but left the MPI in March 1957 and settled at the nuclear research center of theKernreaktor Bau- und Betriebsgesellchaft mbH. close to Karlsruhe. C.F. von Weizsäcker did not, go to Munich either, as he accepted in June 1957 a call to a philosophy chair at the University of Hamburg. Yet he remained a regular guest in the Munich MPI during his semester vacations.