Otto Hahn

Hahn's intention was still to work in industry. He received an offer of employment from Eugen Fischer, the director of

Hahn completed his habilitation in the spring of 1907, and became a Privatdozent. A thesis was not required; the Chemical Institute accepted one of his publications on radioactivity instead.^[19] Most of the organic chemists at the Chemical Institute did not regard Hahn's work as real chemistry.^[20] Fischer objected to Hahn's contention in his habilitation colloquium that many radioactive substances existed in such tiny amounts that they could only be detected by their radioactivity, venturing that he had always been able to detect substances with his keen sense of smell, but soon gave in.^[15] One department head remarked: "it is incredible what one gets to be a Privatdozent these days!"^[20]

Physicists were more accepting of Hahn's work, and he began attending a colloquium at the Physics Institute conducted by Heinrich Rubens. It was at one of these colloquia where, on 28 September 1907, he made the acquaintance of the Austrian physicist Lise Meitner. Almost the same age as himself, she was only the second woman to receive a doctorate from the University of Vienna, and had already published two papers on radioactivity. Rubens suggested her as a possible collaborator. So began the thirty-year collaboration and lifelong close friendship between the two scientists.^[20][21]

In Montreal, Hahn had worked with physicists including at least one woman,

Harriet Brooks observed a radioactive recoil in 1904, but interpreted it wrongly. Hahn and Meitner succeeded in demonstrating the radioactive recoil incident to alpha particle emission and interpreted it correctly. Hahn pursued a report by Stefan Meyer and Egon Schweidler of a decay product of actinium with a half-life of about 11.8 days. Hahn determined that it was actinium X (radium-223). Moreover, he discovered that at the moment when a radioactinium (thorium-227) atom emits an alpha particle, it does so with great force, and the actinium X experiences a recoil. This is enough to free it from chemical bonds, and it has a positive charge, and can be collected at a negative electrode.^[25] Hahn was thinking only of actinium, but on reading his paper, Meitner told him that he had found a new way of detecting radioactive substances. They set up some tests, and soon found actinium C'' (thallium-207) and thorium C'' (thallium-208).^[25] The physicist Walther Gerlach described radioactive recoil as "a profoundly significant discovery in physics with far-reaching consequences".^[26]

In 1910, Hahn was appointed professor by the Prussian Minister of Culture and Education,

The move to new accommodation was fortuitous, as the wood shop had become thoroughly contaminated by radioactive liquids that had been spilt, and radioactive gases that had vented and then decayed and settled as radioactive dust, making sensitive measurements impossible. To ensure that their clean new laboratories stayed that way, Hahn and Meitner instituted strict procedures. Chemical and physical measurements were conducted in different rooms, people handling radioactive substances had to follow protocols that included not shaking hands, and rolls of toilet paper were hung next to every telephone and door handle. Strongly radioactive substances were stored in the old wood shop, and later in a purpose-built radium house on the institute grounds.[29]

Marriage to Edith Junghans

With a regular income, Hahn was now able to contemplate marriage. In June 1911, while attending a conference in

Their only child, Hanno Hahn [de], was born on 9 April 1922. During World War II, he enlisted in the army in 1942, and served with distinction on the Eastern Front as a panzer commander. He lost an arm in combat. After the war he became a distinguished art historian and architectural researcher (at the Hertziana in Rome), known for his discoveries in the early Cistercian architecture of the 12th century. In August 1960, while on a study trip in France, Hanno died in a car accident, together with his wife and assistant Ilse Hahn née Pletz. They left a fourteen-year-old son, Dietrich Hahn.^[31]

In 1990, the Hanno and Ilse Hahn Prize [de] for outstanding contributions to Italian art history was established in memory of Hanno and Ilse Hahn to support young and talented art historians. It is awarded biennially by the Bibliotheca Hertziana – Max Planck Institute for Art History in Rome.^[32]

World War I

In July 1914—shortly before the outbreak of World War I—Hahn was recalled to active duty with the army in a Landwehr regiment. They marched through Belgium, where the platoon he commanded was armed with captured machine guns. He was awarded the Iron Cross (2nd Class) for his part in the First Battle of Ypres. He was a joyful participant in the Christmas truce of 1914, and was commissioned as a lieutenant.^[33] In mid-January 1915, he was summoned to meet chemist Fritz Haber, who explained his plan to break the trench deadlock with chlorine gas. Hahn raised the issue that the Hague Convention banned the use of projectiles containing poison gases, but Haber explained that the French had already initiated chemical warfare with tear gas grenades, and he planned to get around the letter of the convention by releasing gas from cylinders instead of shells.^[34]

Haber's new unit was called Pioneer Regiment 35. After brief training in Berlin, Hahn, together with physicists James Franck and Gustav Hertz, was sent to

In 1913, chemists Frederick Soddy and

Most of the students, laboratory assistants and technicians had been called up, so Hahn, who was stationed in Berlin between January and September 1917,[38] and Meitner had to do everything themselves. By December 1917 she was able to isolate the substance, and after further work were able to prove that it was indeed the missing isotope. Meitner submitted her and Hahn´s findings for publication in March 1918 to the scientific paper Physikalischen Zeitschrift under the title Die Muttersubstanz des Actiniums; ein neues radioaktives Element von langer Lebensdauer.^[37][39]

Although Fajans and Göhring had been the first to discover the element, custom required that an element was represented by its longest-lived and most abundant isotope, and brevium did not seem appropriate. Fajans agreed to Meitner and Hahn naming the element protoactinmium,^[40] and assigning it the chemical symbol Pa.^[41] In June 1918, Soddy and John Cranston announced that they had extracted a sample of the isotope, but unlike Hahn and Meitner were unable to describe its characteristics. They acknowledged Hahn´s and Meitner's priority, and agreed to the name.^[42] The connection to uranium remained a mystery, as neither of the known isotopes of uranium decayed into protactinium. It remained unsolved until the mother isotope, uranium-235, was discovered in 1929.^[37][43]

For their discovery Hahn and Meitner were repeatedly nominated for the Nobel Prize in Chemistry in the 1920s by several scientists, among them Max Planck,

With the discovery of protactinium, most of the decay chains of uranium had been mapped. When Hahn returned to his work after the war, he looked back over his 1914 results, and considered some anomalies that had been dismissed or overlooked. He dissolved uranium salts in a hydrofluoric acid solution with tantalic acid. First the tantalum in the ore was precipitated, then the protactinium. In addition to the uranium X1 (thorium-234) and uranium X2 (protactinium-234), Hahn detected traces of a radioactive substance with a half life of between 6 and 7 hours. There was one isotope known to have a half life of 6.2 hours, mesothorium II (actinium-228). This was not in any probable decay chain, but it could have been contamination, as the Kaiser Wilhelm Institute for Chemistry had experimented with it. Hahn and Meitner demonstrated in 1919 that when actinium is treated with hydrofluoric acid, it remains in the insoluble residue. Since mesothorium II was an isotope of actinium, the substance was not mesothorium II; it was protactinium.^[47][48] Hahn was now confident enough that he had found something that he named his new isotope "uranium Z", and in February 1921, he published the first report on his discovery.^[49]

Hahn determined that uranium Z had a half life of around 6.7 hours (with a two per cent margin of error) and that when uranium X1 decayed, it became uranium X2 about 99.75 per cent of the time, and uranium Z around 0.25 per cent of the time. He found that the proportion of uranium X to uranium Z extracted from several kilograms of

Uranium Z was the first example of nuclear isomerism. Walther Gerlach later remarked that this was "a discovery that was not understood at the time but later became highly significant for nuclear physics".^[26] Not until 1936 was Carl Friedrich von Weizsäcker able to provide a theoretical explanation of the phenomenon.^[51][52] For this discovery, whose full significance was recognised by very few, Hahn was again proposed for the Nobel Prize in Chemistry by Bernhard Naunyn, Goldschmidt and Planck.^[44]

Applied Radiochemistry

In 1924, Hahn was elected to full membership of the Prussian Academy of Sciences in Berlin, by a vote of thirty white balls to two black.^[53] While still remaining the head of his own department, he became Deputy Director of the Kaiser Wilhelm Institute for Chemistry in 1924, and succeeded Alfred Stock as the director in 1928.^[54] Meitner became the director of the Physical Radioactivity Division, while Hahn headed the Chemical Radioactivity Division.^[55] In the early 1920s, he created a new line of research. Using the "emanation method", which he had recently developed, and the "emanation ability", he founded what became known as "applied radiochemistry" for the researching of general chemical and physical-chemical questions. In 1936 Cornell University Press published a book in English (and later in Russian) titled Applied Radiochemistry, which contained the lectures given by Hahn when he was a visiting professor at Cornell University in Ithaca, New York, in 1933. This important publication had a major influence on almost all nuclear chemists and physicists in the United States, the United Kingdom, France, and the Soviet Union during the 1930s and 1940s.^[56]

In 1966, Glenn T. Seaborg, co-discoverer of many transuranium elements, wrote about this book as follows:

As a young graduate student at the University of California at Berkeley in the mid-1930s and in connection with our work with plutonium a few years later, I used his book Applied Radiochemistry as my bible. This book was based on a series of lectures which Professor Hahn had given at Cornell in 1933; it set forth the "laws" for the

co-precipitation of minute quantities of radioactive materials when insoluble substances were precipitated from aqueous solutions. I recall reading and rereading every word in these laws of co-precipitation many times, attempting to derive every possible bit of guidance for our work, and perhaps in my zealousness reading into them more than the master himself had intended. I doubt that I have read sections in any other book more carefully or more frequently than those in Hahn's Applied Radiochemistry. In fact, I read the entire volume repeatedly and I recall that my chief disappointment with it was its length. It was too short.^[56]

Hahn is referred to as the father of nuclear chemistry, which emerged from applied radiochemistry.[57]^[58][59]

National socialism

Hahn spent February to June 1933 in the United States and Canada as a visiting professor at Cornell University.^[62] He gave an interview to the Toronto Star Weekly in which he painted a flattering portrait of Adolf Hitler:

I am not a Nazi. But Hitler is the hope, the powerful hope, of German youth... At least 20 million people revere him. He began as a nobody, and you see what he has become in ten years.… In any case for the youth, for the nation of the future, Hitler is a hero, a Führer, a saint... In his daily life he is almost a saint. No alcohol, not even tobacco, no meat, no women. In a word: Hitler is an unequivocal Christ.^[63]

The April 1933 Law for the Restoration of the Professional Civil Service banned Jews and communists from academia. Meitner was exempt from its impact because she was an Austrian rather than a German citizen.^[64] Haber was likewise exempt as a veteran of World War I, but chose to resign his directorship of the Kaiser Wilhelm Institute of Physical Chemistry and Electrochemistry in protest on 30 April 1933, but the directors of the other Kaiser Wilhelm Institutes, even the Jewish ones, complied with the new law,^[65] which applied to the KWS as a whole and those Kaiser Wilhelm institutes with more than 50% state support, which exempted the KWI for Chemistry.^[66] Hahn therefore did not have to fire any of his own full-time staff, but as the interim director of Haber's institute, he dismissed a quarter of its staff, including three department heads. Gerhart Jander was appointed the new director of Haber's old institute, and, ironically, reoriented it towards chemical warfare research.^[67]

Like most KWS institute directors, Haber had accrued a large discretionary fund. It was his wish that it be distributed to the dismissed staff to facilitate their emigration, but the Rockefeller Foundation insisted that the funds either be used for scientific research or returned. Hahn brokered a deal whereby 10 per cent of the funds would be allocated to Haber's people. In August 1933 the administrators of the KWS were alerted that several boxes of Rockefeller Foundation-funded equipment was about to be shipped to Herbert Freundlich, one of the department heads that Hahn had dismissed, in England. Hahn complied with an order to halt the shipment, but when Planck, the president of the KWS since 1930, returned from vacation, he ordered Hahn to expedite the shipment.^[67][68]

Haber died on 29 January 1934. A memorial service was held on the first anniversary of his death. University professors were forbidden to attend, so they sent their wives in their place. Hahn, Planck and Joseph Koeth attended, and gave speeches.^[67][69] The aging Planck did not seek re-election, and was succeeded in 1937 as president by Carl Bosch, a Nobel Prize winner in Chemistry and the Chairman of the Board of IG Farben, a company which had bankrolled the Nazi Party since 1932. Ernst Telschow became Secretary of the KWS. Telschow was an enthusiastic supporter of the Nazis, but was also loyal to Hahn, being one of his former students, and Hahn welcomed his appointment.^[70][67] Hahn's chief assistant, Otto Erbacher, became the KWI for Chemistry's party steward (Vertrauensmann).^[71]

Rubidium–strontium dating

While Hahn was in North America, his attention was drawn to a mica-like mineral from

In May 1937, they issued parallel reports, one in Zeitschrift für Physik with Meitner as the principal author, and one in Chemische Berichte with Hahn as the principal author.^[88][89][90] Hahn concluded his by stating emphatically: Vor allem steht ihre chemische Verschiedenheit von allen bisher bekannten Elementen außerhalb jeder Diskussion ("Above all, their chemical distinction from all previously known elements needs no further discussion");^[90] Meitner was increasingly uncertain. She considered the possibility that the reactions were from different isotopes of uranium; three were known: uranium-238, uranium-235 and uranium-234. However, when she calculated the neutron cross section, it was too large to be anything other than the most abundant isotope, uranium-238. She concluded that it must be another case of the nuclear isomerism that Hahn had discovered in protactinium. She therefore ended her report on a very different note to Hahn, reporting that: "The process must be neutron capture by uranium-238, which leads to three isomeric nuclei of uranium-239. This result is very difficult to reconcile with current concepts of the nucleus."^[89][91]

With the Anschluss, Germany's unification with Austria on 12 March 1938, Meitner lost her Austrian citizenship,^[92] and fled to Sweden. She carried only a little money, but before she left, Hahn gave her a diamond ring he had inherited from his mother.^[93] Meitner continued to correspond with Hahn by mail. In late 1938 Hahn and Strassmann found evidence of isotopes of an alkaline earth metal in their sample. Finding a group 2 alkaline earth metal was problematic, because it did not logically fit with the other elements found thus far. Hahn initially suspected it to be radium, produced by splitting off two alpha-particles from the uranium nucleus, but chipping off two alpha particles via this process was unlikely. The idea of turning uranium into barium (by removing around 100 nucleons) was seen as preposterous.^[94]

During a visit to Copenhagen on 10 November, Hahn discussed these results with Niels Bohr, Lise Meitner, and Otto Robert Frisch.^[94] Further refinements of the technique, leading to the decisive experiment on 16–17 December 1938, produced puzzling results: the three isotopes consistently behaved not as radium, but as barium. Hahn, who did not inform the physicists in his Institute, described the results exclusively in a letter to Meitner on 19 December:

We are more and more coming to the awful conclusion that our Ra isotopes behave not like Ra, but like Ba... Perhaps you can come up with some fantastic explanation. We ourselves realize that it can't actually burst apart into Ba. Now we want to test whether the Ac-isotopes derived from the "Ra" behave not like Ac but like La.^[95]

In her reply, Meitner concurred. "At the moment, the interpretation of such a thoroughgoing breakup seems very difficult to me, but in nuclear physics we have experienced so many surprises, that one cannot unconditionally say: 'it is impossible'." On 22 December 1938, Hahn sent a manuscript to

Life became precarious for those married to Jewish women. One was Philipp Hoernes, a chemist working for Auergesellschaft, the firm that mined the uranium ore used by the project. After the firm let him go in 1944, Hoernes faced being conscripted for forced labour. At the age of 60, it was doubtful that he would survive. Hahn and Nikolaus Riehl arranged for Hoernes to work at the Kaiser Wilhelm Institute for Chemistry, claiming that his work was essential to the uranium project and that uranium was highly toxic, making it hard to find people to work with it. Hahn was aware that uranium ore was fairly safe in the laboratory, although not so much for the 2,000 female slave labourers from Sachsenhausen concentration camp who mined it in Oranienburg. Another physicist with a Jewish wife was Heinrich Rausch von Traubenberg [de]. Hahn certified that his work was important to the war effort, and that his wife Maria, who had a doctorate in physics, was required as his assistant. After he died on 19 September 1944, Maria faced being sent to a concentration camp. Hahn mounted a lobbying campaign to get her released, but to no avail, and she was sent to the Theresienstadt Ghetto in January 1945. She survived the war, and was reunited with her daughters in England after the war.^[111][112]

Incarceration

On 25 April 1945, an armoured task force from the British/American

They were relocated to the Château de Facqueval in

On 16 November 1945 the Royal Swedish Academy of Sciences announced that Hahn had been awarded the 1944 Nobel Prize in Chemistry "for his discovery of the fission of heavy atomic nuclei."^[124][125] Hahn was still at Farm Hall when the announcement was made; thus, his whereabouts were a secret, and it was impossible for the Nobel committee to send him a congratulatory telegram. Instead, he learned about his award on 18 November through the Daily Telegraph.^[126] His fellow interned scientists celebrated his award by giving speeches, making jokes, and composing songs.^[127]

Hahn had been nominated for the chemistry and the physics Nobel prizes many times even before the discovery of nuclear fission. Several more followed for the discovery of fission.^[44] The Nobel prize nominations were vetted by committees of five, one for each award. Although Hahn and Meitner received nominations for physics, radioactivity and radioactive elements had traditionally been seen as the domain of chemistry, and so the Nobel Committee for Chemistry evaluated the nominations. The committee received reports from Theodor Svedberg and Arne Westgren [de; sv]. These chemists were impressed by Hahn's work, but felt that of Meitner and Frisch was not extraordinary, and did not understand why the physics community regarded their work as seminal. As for Strassmann, although his name was on the papers, there was a long-standing policy of conferring awards on the most senior scientist in a collaboration. The committee therefore recommended that Hahn alone be given the chemistry prize.^[128]

Under Nazi rule, Germans had been forbidden to accept Nobel prizes after the Nobel Peace Prize had been awarded to Carl von Ossietzky in 1936.^[129] The Nobel Committee for Chemistry's recommendation was therefore rejected by the Royal Swedish Academy of Sciences in 1944, which also decided to defer the award for one year. When the Academy reconsidered the award in September 1945, the war was over and thus the German boycott had ended. Also, the chemistry committee had now become more cautious, as it was apparent that much research had taken place in the United States in secret, and suggested deferring for another year, but the Academy was swayed by Göran Liljestrand, who argued that it was important for the Academy to assert its independence from the Allies of World War II, and award the prize to a German, as it had done after World War I when it had awarded it to Fritz Haber. Hahn therefore became the sole recipient of the 1944 Nobel Prize for Chemistry.^[128]

The invitation to attend the Nobel festivities was transmitted via the British Embassy in Stockholm.^[130] On 4 December, Hahn was persuaded by two of his Alsos captors, American Lieutenant Colonel Horace K. Calvert and British Lieutenant Commander Eric Welsh, to write a letter to the Nobel committee accepting the prize but stating that he would not be able to attend the award ceremony on 10 December since his captors would not allow him to leave Farm Hall. When Hahn protested, Welsh reminded him that Germany had lost the war.^[131] Under the Nobel Foundation statutes, Hahn had six months to deliver the Nobel Prize lecture, and until 1 October 1946 to cash the 150,000 Swedish krona cheque.^[132][133]

Hahn was repatriated from Farm Hall on 3 January 1946, but it soon became apparent that difficulties obtaining permission to travel from the British government meant that he would be unable to travel to Sweden before December 1946. Accordingly, the Academy of Sciences and the Nobel Foundation obtained an extension from the Swedish government.

The suicide of Albert Vögler on 14 April 1945 left the KWS without a president.^[54] The British chemist Bertie Blount was placed in charge of its affairs while the Allies decided what to do with it, and he decided to install Max Planck as an interim president. Now aged 87, Planck was in the small town of Rogätz, in an area that the Americans were preparing to hand over to the Soviet Union. The Dutch astronomer Gerard Kuiper from the Alsos Mission fetched Planck in a jeep and brought him to Göttingen on 16 May.^[136][137] Planck wrote to Hahn, who was still in captivity in England, on 25 July, and informed Hahn that the directors of the KWS had voted to make him the next president, and asked if he would accept the position.^[54] Hahn did not receive the letter until September, and did not think he was a good choice, as he regarded himself as a poor negotiator, but his colleagues persuaded him to accept. After his return to Germany, he assumed the office on 1 April 1946.^[138][139]

After the Second World War, Hahn came out strongly against the use of nuclear energy for military purposes. He saw the application of his scientific discoveries to such ends as a misuse, or even a crime. Lawrence Badash wrote: "His wartime recognition of the perversion of science for the construction of weapons and his postwar activity in planning the direction of his country's scientific endeavours now inclined him increasingly toward being a spokesman for social responsibility."[150]

In early 1954, he wrote the article "Cobalt 60 – Danger or Blessing for Mankind?", about the misuse of atomic energy, which was widely reprinted and transmitted in the radio in Germany, Norway, Austria, and Denmark, and in an English version worldwide via the BBC. The international reaction was encouraging.

In 1959 Hahn co-founded in Berlin the Federation of German Scientists (VDW), a non-governmental organization, which has been committed to the ideal of responsible science. The members of the Federation feel committed to taking into consideration the possible military, political, and economical implications and possibilities of atomic misuse when carrying out their scientific research and teaching. With the results of its interdisciplinary work the VDW not only addresses the general public, but also the decision-makers at all levels of politics and society.^[158] Right up to his death, Otto Hahn never tired of warning urgently of the dangers of the nuclear arms race between the great powers and of the radioactive contamination of the planet.^[159] The historian Lawrence Badash wrote:

The important thing is not that scientists may disagree on where their responsibility to society lies, but that they are conscious that a responsibility exists, are vocal about it, and when they speak out they expect to affect policy. Otto Hahn, it would seem, was even more than just an example of this twentieth-century conceptual evolution; he was a leader in the process.^[160]

He was one of the signatories of the agreement to convene a convention for drafting a

Hahn was shot in the back by a disgruntled inventor in October 1951, injured in a motor vehicle accident in 1952, and had a minor heart attack in 1953. In 1962, he published a book, Vom Radiothor zur Uranspaltung (From the radiothor to Uranium fission). It was released in English in 1966 with the title Otto Hahn: A Scientific Autobiography, with an introduction by Glenn Seaborg. The success of this book may have prompted him to write another, fuller autobiography, Otto Hahn. Mein Leben, but before it could be published, he fractured one of the vertebrae in his neck while getting out of a car. He gradually became weaker and died in Göttingen on 28 July 1968. His wife Edith survived him by only a fortnight.^[164] He was buried in the Stadtfriedhof in Göttingen.^[165] The day after his death, the Max Planck Society published the following obituary notice in all the major newspapers in Germany, Austria, and Switzerland:

On 28 July, in his 90th year, our Honorary President Otto Hahn passed away. His name will be recorded in the history of humanity as

the founder of the atomic age. In him Germany and the world have lost a scholar who was distinguished in equal measure by his integrity and personal humility. The Max Planck Society mourns its founder, who continued the tasks and traditions of the Kaiser Wilhelm Society after the war, and mourns also a good and much loved human being, who will live in the memories of all who had the chance to meet him. His work will continue. We remember him with deep gratitude and admiration.^[166]

The number of those who had been able to be near Otto Hahn is small. His behaviour was completely natural for him, but for the next generations he will serve as a model, regardless of whether one admires in the attitude of Otto Hahn his humane and scientific sense of responsibility or his personal courage.[167]

Otto Robert Frisch recalled:

Hahn remained modest and informal all his life. His disarming frankness, unfailing kindness, good common sense, and impish humour will be remembered by his many friends all over the world.^[168]

The Royal Society in London wrote in an obituary:

It was remarkable, how, after the war, this rather unassuming scientist who had spent a lifetime in the laboratory, became an effective administrator and an important public figure in Germany. Hahn, famous as the discoverer of nuclear fission, was respected and trusted for his human qualities, simplicity of manner, transparent honesty, common sense and loyalty.^[169]

Honors and awards

During his lifetime Hahn was awarded orders, medals, scientific prizes, and fellowships of Academies, Societies, and Institutions from all over the world. At the end of 1999, the German news magazine Focus published an inquiry of 500 leading natural scientists, engineers, and physicians about the most important scientists of the 20th century. In this poll Hahn was elected third (with 81 points), after the theoretical physicists Albert Einstein and Max Planck, and thus the most significant chemist of his time.^[170]

As well as the Nobel Prize in Chemistry (1944), Hahn was awarded:

• the
  Emil Fischer Medal of the Society of German Chemists (1922),^[171]
• the Cannizaro Prize of the Royal Academy of Science in Rome (1938),[171]
• the Copernicus Prize of the
  University of Konigsberg (1941),^[171]
• the Gothenius Medal of the
  Akademie der Naturforscher (1943),^[171]
• the Max Planck Medal of the German Physical Society, with Lise Meitner (1949),^[171]
• the Goethe Medal of the city of Frankfurt-on-the-Main (1949),^[171]
• the Golden Paracelsus Medal of the Swiss Chemical Society (1953),^[171]
• the Faraday Lectureship Prize with Medal from the Royal Society of Chemistry (1956),^[171]
• the Grotius Medal of the Hugo Grotius Foundation (1956),^[171]
• Wilhelm Exner Medal of the Austrian Industry Association (1958),^[172]
• the
  Helmholtz Medal
  of the Berlin-Brandenburg Academy of Sciences and Humanities (1959),
• and the
  Harnack medal in Gold from the Max Planck Society (1959).^[173][174]

Hahn became the honorary president of the Max Planck Society in 1962.^[175]

• He was elected a
  Foreign Member of the Royal Society (1957).^[176]
• His honorary memberships of foreign academies and scientific societies included:
  • the Romanian Physical Society in Bucharest,[177]
  • the Royal Spanish Society for Chemistry and Physics and the Spanish National Research Council,^[177]
  • and the Academies in
    Allahabad, Bangalore, Berlin, Boston, Bucharest, Copenhagen, Göttingen, Halle, Helsinki, Lisbon, Madrid, Mainz, Munich, Rome, Stockholm, Vatican, and Vienna.^[177]

He was an honorary fellow of University College London,[177]

• and an honorary citizen of the cities of Frankfurt am Main and Göttingen in 1959,
• and of Berlin (1968).^[171]
• Hahn was made an Officer of the Ordre National de la
  Légion d'Honneur of France (1959),^[171]
• and was awarded the Grand Cross First Class of the Order of Merit of the Federal Republic of Germany (1959).^[171]
• In 1966, US President Lyndon B. Johnson and the United States Atomic Energy Commission (AEC) awarded Hahn, Lise Meitner and Fritz Strassmann the Enrico Fermi Award. The diploma for Hahn bore the words: "For pioneering research in the naturally occurring radioactivities and extensive experimental studies culminating in the discovery of fission."^[178]
• He received honorary doctorates from
  • the
    University of Gottingen,^[171]
  • the Technische Universität Darmstadt,^[171]
  • the University of Frankfurt in 1949,^[171]
  • and the University of Cambridge in 1957.^[171]

Objects named after Hahn include:

• NS Otto Hahn, the only European nuclear-powered civilian ship (1964),^[179]
• a crater on the Moon (shared with his namesake Friedrich von Hahn),^[180]
• and the asteroid
  19126 Ottohahn,^[181]
• the Otto Hahn Prize of both the German Chemical and Physical Societies and the city of Frankfurt/Main,^[182]
• the Otto Hahn Medal and the Otto Hahn Award of the Max Planck Society,^[183][184]
• and the Otto Hahn Peace Medal in Gold of the United Nations Association of Germany (DGVN) in Berlin (1988).^[185]

Proposals were made at various times, first in 1971 by American chemists, that the newly synthesised element 105 should be named hahnium in Hahn's honour, but in 1997 the IUPAC named it dubnium, after the Russian research centre in Dubna. In 1992 element 108 was discovered by a German research team, and they proposed the name hassium (after Hesse). In spite of the long-standing convention to give the discoverer the right to suggest a name, a 1994 IUPAC committee recommended that it be named hahnium.^[186] After protests from the German discoverers, the name hassium (Hs) was adopted internationally in 1997.^[187]

See also

• List of peace activists

Publications in English

• Hahn, Otto (1936). Applied Radiochemistry. Ithaca, New York: Cornell University Press.
• Hahn, Otto (1950). New Atoms: Progress and Some Memories. New York-Amsterdam-London-Brussels: Elsevier Inc.
• Hahn, Otto (1966). Otto Hahn: A Scientific Autobiography. Translated by Ley, Willy. New York: Charles Scribner's Sons.
• Hahn, Otto (1970). My Life. Translated by Kaiser, Ernst; Wilkins, Eithne. New York: Herder and Herder.

Notes

References

• Badash, Lawrence (1983). "Otto Hahn, Science, and Social Responsibility". In Shea, William R. (ed.). Otto Hahn and the Rise of Nuclear Physics. The University of Western Ontario Series in the Philosophy of Science. Vol. 22. Dordrecht / Boston / Lancaster: D. Reidel Publishing Company. pp. 167–180.
  OCLC 797094010
  .
• Berninger, Ernst (1983). "The Discovery of Uranoium Z by Otto Hahn: The First Example of Nuclear Isomerism". In Shea, William R. (ed.). Otto Hahn and the Rise of Nuclear Physics. The University of Western Ontario Series in the Philosophy of Science. Vol. 22. Dordrecht / Boston / Lancaster: D. Reidel Publishing Company. pp. 213–220.
  OCLC 797094010
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• OCLC 7324621011
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• Bowen, Robert (1994). Isotopes in the Earth Sciences. London: Chapman and Hall.
  ISBN 978-0-412-53710-3
  .
• Crawford, Elisabeth;
  ISSN 0031-9228
  .
• Crawford, Elisabeth (2000). "German Scientists and Hitler's Vendetta against the Nobel Prizes". Historical Studies in the Physical and Biological Sciences. 31 (1): 37–53.
  JSTOR 27757845
  .
• OCLC 861058137
  .
• OCLC 473315990
  .
• Hahn, Dietrich, ed. (1988). Otto Hahn - Leben und Werk in Texten und Bildern (in German). Frankfurt am Main: Suhrkamp-Insel Publishers.
  OCLC 42847178
  .
• Hahn, Otto (1966). Otto Hahn: A Scientific Autobiography. Translated by Ley, Willy. New York: Charles Scribner's Sons.
  OCLC 646422716
  .
• Hoffmann, Klaus (2001). Otto Hahn: Achievement and Responsibility. Translated by Cole, J. Michael. Springer.
  OCLC 468996162
  .
• Macrakis, Kristie (1993). Surviving the Swastika: Scientific Research in Nazi Germany. Oxford University Press.
  OCLC 538154456
  .
• Norris, Robert S. (2002). Racing for the Bomb: General Leslie R. Groves, the Manhattan Project's Indispensable Man. South Royalton, Vermont: Steerforth Press.
  OCLC 48544060
  .
• OCLC 224864936
  .
• OCLC 32893857
  .
• Sime, Ruth Lewin (2004). Otto Hahn und die Max-Planck-Gesellschaft Zwischen Vergangenheit und Erinnerung (PDF) (in German). Berlin: Max-Planck-Gesellschaft. Archived (PDF) from the original on 30 March 2005. Retrieved 28 June 2020.
• S2CID 119479637
  .
• Spence, Robert (1970). "Otto Hahn 1879–1968". Biographical Memoirs of Fellows of the Royal Society. 16: 279–313.
  doi:10.1098/rsbm.1970.0010
  .
• Stolz, Werner (1989). "Die Arbeitsgemeinschaft Hahn — Meitner". Otto Hahn/Lise Meitner. Biographien hervorragender Naturwissenschaftler, Techniker und Mediziner (in German). Vieweg+Teubner Verlag. pp. 19–41.
  OCLC 263971970
  .
• Walker, Mark (May 2006). "Otto Hahn: Responsibility and Repression". Physics in Perspective. 8 (2): 116–163.
  S2CID 120992662
  .
• Walker, Mark (1993). German National Socialism and the Quest for Nuclear Power. Cambridge University Press.
  OCLC 722061969
  .
• Yruma, Jeris Stueland (November 2008). How Experiments Are Remembered: The Discovery of Nuclear Fission, 1938–1968 (PhD thesis). Princeton University.

Further reading

• Berninger, Ernst H. (1970). Otto Hahn 1879–1968. Bonn: Inter Nationes.
  OCLC 168069
  .
• Beyerchen, Alan D. (1977). Scientists under Hitler. New Haven and London: Yale University Press.
  OCLC 970896098
  .
• Feldman, Anthony; Ford, Peter (1979). Otto Hahn – in: Scientists and Inventors. London: Aldus Books.
• Graetzer, Hans D.; Anderson, David L. (1971). The Discovery of Nuclear Fission: A Documentary History. New York: Van Nostrand-Reinhold.
  OCLC 1130319295
  .
• Hahn, Otto (1970). My Life. Translated by Kaiser, Ernst; Wilkins, Eithne. New York: Herder and Herder.
  OCLC 317354004
  .
• Kant, Horst (2002). Werner Heisenberg and the German Uranium Project. Otto Hahn and the declarations of Mainau and Göttingen. Berlin: Max-Planck-Insitut für Wissenschaftsgeschichte.
• Reid, Robert William (1969). Tongues of Conscience: War and the Scientist's Dilemma. London: Constable & Co.
  OCLC 638683343
  .
• Whiting, Jim (2004). Otto Hahn and the Discovery of Nuclear Fission. Unlocking the Secrets of Science. Bear, Delaware: Mitchell Lane.
  OCLC 52312062
  .

External links

Wikimedia Commons has media related to Otto Hahn.

Wikiquote has quotations related to Otto Hahn.

• Otto Hahn – winner of the Enrico Fermi Award 1966 U.S Government, Department of Energy
• Otto Hahn on Nobelprize.org including the Nobel Lecture on 13 December 1946 From the Natural Transmutations of Uranium to Its Artificial Fission
• Award Ceremony Speech honoring Otto Hahn by Professor Arne Westgren, Stockholm.
• Otto Hahn and the Discovery of Nuclear Fission Archived 1 February 2014 at the Wayback Machine BR, 2008
• Otto Hahn – Discoverer of Nuclear Fission Author: Dr. Anne Hardy (Pro-Physik, 2004)
• Otto Hahn (1879–1968) – The discovery of fission Visit Berlin, 2011.
• Otto Hahn – Discoverer of nuclear fission
• Otto Hahn – Founder of the Atomic Age Author: Dr Edmund Neubauer (Translation: Brigitte Hippmann) – Website of the Otto Hahn Gymnasium (OHG), 2007.
• Otto Hahn Award
• Otto Hahn Peace Medal in Gold Website of the United Nations Association of Germany (DGVN) in Berlin
• Otto Hahn Medal
• The history of the Hahn Meitner Institute (HMI) Helmholtz-Zentrum, Berlin 2011.
• Otto Hahn heads a delegation to Israel 1959 Website of the Max Planck Society, 2011.
• Biography Otto Hahn 1879–1968
• Otto Hahn – A Life for Science, Humanity and Peace Archived 24 September 2015 at the Wayback Machine Hiroshima University Peace Lecture, held by Dietrich Hahn, 2 October 2013.
• Otto Hahn – Discoverer of nuclear fission, grandfather of the Atombomb GMX, Switzerland, 17 December 2013. Author: Marinus Brandl.
• Newspaper clippings about Otto Hahn in the 20th Century Press Archives of the ZBW