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. As well as the Nobel Prize in Chemistry (1944), Hahn was awarded: Hahn became the honorary president of the Max Planck Society in 1962.
Honors and awards
Otto Hahn
Otto Hahn | Honors and awards
Yes. Nobel Prize in Chemistry in 1944 along with many others. Yes, the Nobel Prize in Chemistry (1944), he  became the honorary president of the Max Planck Society in 1962. The Nobel Prize in Chemistry in 1944. Yes, the 1944 Nobel Prize in Chemistry
where do the nuclear and weak interaction forces occur
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In the Nuclear Fission
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what is this process about?
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The weak interaction, also known as the weak force or weak nuclear force, is the mechanism of interaction between subatomic particles responsible for the radioactive decay of atoms.
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what is meant by the process where it occur?
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Nuclear fission is a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into two or more smaller, lighter nuclei.
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who discovered it?
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German Otto Hahn and his assistant Fritz Strassmann
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where is the former from?
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He was from Frankfurt am Main
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what else has he discovered?
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Radioactive isotopes of radium, thorium, protactinium and uranium, Phenomena of Radioactive recoil & Nuclear Isomerism among many others.
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did he receive any award?
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This came with an annual salary of 5,000 marks. In addition, he received 66,000 marks in 1914 (of which he gave 10 per cent to Meitner) from Knöfler for the mesothorium process. The new institute was inaugurated on 23 October 1912 in a ceremony presided over by Kaiser Wilhelm II. The Kaiser was shown glowing radioactive substances in a dark room. 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.
Otto Hahn | Discovery of radioactive recoil
Along the way, Hahn determined that just as he was unable to separate thorium from radiothorium, so he could not separate mesothorium from radium. 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. Most of the organic chemists at the Chemical Institute did not regard Hahn's work as real chemistry. 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.
Otto Hahn | Discovery of mesothorium I
Otto Hahn (8 March 1879 – 28 July 1968) was a German chemist, and a pioneer in the fields of radioactivity and radiochemistry. Hahn is referred to as the father of nuclear chemistry. Hahn and Lise Meitner discovered radioactive isotopes of radium, thorium, protactinium and uranium. He also discovered the phenomena of radioactive recoil and nuclear isomerism, and pioneered rubidium–strontium dating. In 1938, Hahn, Lise Meitner and Fritz Strassmann discovered nuclear fission, for which Hahn received the 1944 Nobel Prize for Chemistry. Nuclear fission was the basis for nuclear reactors and nuclear weapons. A graduate of the University of Marburg, Hahn studied under Sir William Ramsay at University College London, and at McGill University in Montreal under Ernest Rutherford, where he discovered several new radioactive isotopes.
Otto Hahn | Introduction
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." 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". His fellow interned scientists celebrated his award by giving speeches, making jokes, and composing songs. Hahn had been nominated for the chemistry and the physics Nobel prizes many times even before the discovery of nuclear fission.
Otto Hahn | The Nobel Prize in Chemistry 1944
He was an honorary fellow of University College London,
Otto Hahn | Honors and awards
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). The physicist Walther Gerlach described radioactive recoil as "a profoundly significant discovery in physics with far-reaching consequences". In 1910, Hahn was appointed professor by the Prussian Minister of Culture and Education, August von Trott zu Solz. Two years later, Hahn became head of the Radioactivity Department of the newly founded Kaiser Wilhelm Institute for Chemistry in Berlin-Dahlem (in what is today the Hahn-Meitner-Building of the Free University of Berlin).
Otto Hahn | Discovery of radioactive recoil
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. As well as the Nobel Prize in Chemistry (1944), Hahn was awarded: Hahn became the honorary president of the Max Planck Society in 1962.
Otto Hahn | Honors and awards
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).
Otto Hahn | Discovery of nuclear isomerism
Rutherford remarked that: "Hahn has a special nose for discovering new elements."
Otto Hahn | Discovery of radio thorium, and other "new elements"
After the war he became the head of the Kaiser Wilhelm Institute for Chemistry, while remaining in charge of his own department. Between 1934 and 1938, he worked with Strassmann and Meitner on the study of isotopes created through the neutron bombardment of uranium and thorium, which led to the discovery of nuclear fission. He was an opponent of national socialism and the persecution of Jews by the Nazi Party that caused the removal of many of his colleagues, including Meitner, who was forced to flee Germany in 1938. During World War II, he worked on the German nuclear weapons program, cataloguing the fission products of uranium.
Otto Hahn | Introduction
Hahn therefore became the sole recipient of the 1944 Nobel Prize in Chemistry "for his discovery of the fission of heavy nuclei".
Discovery of nuclear fission | Nobel Prize
(In fact, it was an isotope of the known element thorium; the concept of an isotope, along with the term, was only coined in 1913, by the British chemist Frederick Soddy). Ramsay was enthusiastic when yet another new element was found in his institute, and he intended to announce the discovery in a correspondingly suitable way. In accordance with tradition this was done before the committee of the venerable Royal Society. At the session of the Royal Society on 16 March 1905 Ramsay communicated Hahn's discovery of radiothorium. The "Daily Telegraph" informed its readers: Hahn published his results in the "Proceedings of the Royal Society" on 24 March 1905.
Otto Hahn | Discovery of radio thorium, and other "new elements"
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". Not until 1936 was Carl Friedrich von Weizsäcker able to provide a theoretical explanation of the phenomenon. 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.
Otto Hahn | Discovery of nuclear isomerism
He returned to Germany in 1906, and Emil Fischer placed a former woodworking shop in the basement of the Chemical Institute at the University of Berlin at his disposal to use as a laboratory. Hahn completed his habilitation in the spring of 1907, and became a "Privatdozent". In 1912, he became head of the Radioactivity Department of the newly founded Kaiser Wilhelm Institute for Chemistry. Working with the Austrian physicist Lise Meitner in the building that now bears their names, he made a series of groundbreaking discoveries, culminating with her isolation of the longest-lived isotope of protactinium in 1918. During World War I he served with a "Landwehr" regiment on the Western Front, and with the chemical warfare unit headed by Fritz Haber on the Western, Eastern and Italian fronts, earning the Iron Cross (2nd Class) for his part in the First Battle of Ypres.
Otto Hahn | Introduction
William Henry Bragg and Richard Kleeman had noted that the alpha particles emitted from radioactive substances always had the same energy, providing a second way of identifying them, so Hahn set about measuring the alpha particle emissions of radiothorium. In the process, he found that a precipitation of thorium A (polonium-216) and thorium B (lead-212) also contained a short-lived "element", which he named thorium C (which was later identified as polonium-212). Hahn was unable to separate it, and concluded that it had a very short half life (it is about 300 ns). He also identified radioactinium (thorium-227) and radium D (later identified as lead-210).
Otto Hahn | Discovery of radio thorium, and other "new elements"
It was the first of over 250 scientific publications of Otto Hahn in the field of radiochemistry. At the end of his time in London, Ramsay asked Hahn about his plans for the future, and Hahn told him about the job offer from Kalle & Co. Ramsay told him radiochemistry had a bright future, and that someone who had discovered a new radioactive element should go to the University of Berlin. Ramsay wrote to Emil Fischer, the head of the chemistry institute there, who replied that Hahn could work in his laboratory, but could not be a "Privatdozent" because radiochemistry was not taught there.
Otto Hahn | Discovery of radio thorium, and other "new elements"
This article is based on a translation of the equivalent article on German Wikipedia
Otto Hahn Prize | References
Source: Society of German Chemists
Otto Hahn Prize | Recipients: Otto Hahn Prize
The "Freundeskreis des Forschungszentrums Karlsruhe e.V." (Friends of the Karlsruhe Research Center) established and awards the "Otto-Haxel-Preis" (Otto Haxel Prize), which is given for achievements in the nuclear energy industry. In 1980, Haxel was awarded the "Otto-Hahn-Preis der Stadt Frankfurt am Main" (Otto Hahn Prize of the City of Frankfurt am Main) for his advocacy of and work on harnessing nuclear energy production.
Otto Haxel | Honors
Hahn's intention was still to work in industry. He received an offer of employment from Eugen Fischer, the director of (and the father of organic chemist Hans Fischer), but a condition of employment was that Hahn had to have lived in another country and have a reasonable command of another language. With this in mind, and to improve his knowledge of English, Hahn took up a post at University College London in 1904, working under Sir William Ramsay, who was known for having discovered the inert gases. Here Hahn worked on radiochemistry, at that time a very new field. In early 1905, in the course of his work with salts of radium, Hahn discovered a new substance he called radiothorium (thorium-228), which at that time was believed to be a new radioactive element.
Otto Hahn | Discovery of radio thorium, and other "new elements"
In 1913, chemists Frederick Soddy and Kasimir Fajans independently observed that alpha decay caused atoms to shift down two places on the periodic table, while the loss of two beta particles restored it to its original position. Under the resulting reorganisation of the periodic table, radium was placed in group II, actinium in group III, thorium in group IV and uranium in group VI. This left a gap between thorium and uranium. Soddy predicted that this unknown element, which he referred to (after Dmitri Mendeleev) as "ekatantalium", would be an alpha emitter with chemical properties similar to tantalium. It was not long before Fajans and Oswald Helmuth Göhring discovered it as a decay product of a beta-emitting product of thorium.
Otto Hahn | Discovery of protactinium
Another reason for the admiration we felt for Otto Hahn was that he never ceased to remind us of our duty to think not only of ourselves, and not only of the developed world, but of the world as a whole."" (Dr. h.c. Hans Koschnick, Bremen, 1995).
Otto Hahn Peace Medal | Statements by prizewinners
Based on the radioactive displacement law of Fajans and Soddy, this was an isotope of the missing element, which they named "brevium" after its short half life. However, it was a beta emitter, and therefore could not be the mother isotope of actinium. This had to be another isotope of the same element. Hahn and Meitner set out to find the missing mother isotope. They developed a new technique for separating the tantalum group from pitchblende, which they hoped would speed the isolation of the new isotope. The work was interrupted by the First World War. Meitner became an X-ray nurse, working in Austrian Army hospitals, but she returned to the Kaiser Wilhelm Institute in October 1916.
Otto Hahn | Discovery of protactinium
After James Chadwick discovered the neutron in 1932, Irène Curie and Frédéric Joliot irradiated aluminium foil with alpha particles, they found that this results in a short-lived radioactive isotope of phosphorus. They noted that positron emission continued after the neutron emissions ceased. Not only had they discovered a new form of radioactive decay, they had transmuted an element into a hitherto unknown radioactive isotope of another, thereby inducing radioactivity where there had been none before. Radiochemistry was now no longer confined to certain heavy elements, but extended to the entire periodic table. Chadwick noted that being electrically neutral, neutrons could penetrate the atomic nucleus more easily than protons or alpha particles.
Otto Hahn | Discovery of nuclear fission
One department head remarked: "it is incredible what one gets to be a "Privatdozent" these days!" 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.
Otto Hahn | Discovery of mesothorium I
Frisch confirmed this experimentally on January 13, 1939. In 1944, Hahn received the Nobel Prize for Chemistry for the discovery of nuclear fission. Some historians have documented the history of the discovery of nuclear fission and believe Meitner should have been awarded the Nobel Prize with Hahn.
Herbert L. Anderson | Education
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. While still remaining the head of his own department, he hecame Deputy Director of the Kaiser Wilhelm Institute for Chemistry in 1924, and succeeded Alfred Stock as the director in 1928. Meitner became the director of the Physical Radioactivity Division, while Hahn headed the Chemical Radioactivity Division. 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.
Otto Hahn | "Applied Radiochemistry"
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.
Otto Hahn | Discovery of radioactive recoil
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."
Otto Hahn | Discovery of nuclear fission
Several more followed for the discovery of fission. 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 . 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.
Otto Hahn | The Nobel Prize in Chemistry 1944
At that time, the existence of actinides was not yet established, and uranium was wrongly believed to be a group 6 element similar to tungsten. It followed that first transuranic elements would be similar to group 7 to 10 elements, i.e. rhenium and platinoids. They established the presence of multiple isotopes of at least four such elements, and (mistakenly) identified them as elements with atomic numbers 93 through 96. They were the first scientists to measure the 23-minute half life of uranium-239 and to establish chemically that it was an isotope of uranium, but were unable to continue this work to its logical conclusion and identify the real element 93.
Otto Hahn | Discovery of nuclear fission
The new laboratories offered new opportunities, as the old ones had become too contaminated with radioactive substances to investigate feebly radioactive substances. They developed a new technique for separating the tantalum group from pitchblende, which they hoped would speed the isolation of the new isotope. The work was interrupted by the outbreak of the First World War in 1914. Hahn was called up into the German Army, and Meitner became a volunteer radiographer in Austrian Army hospitals. She returned to the Kaiser Wilhelm Institute in October 1916, when not only Hahn, but most of the students, laboratory assistants and technicians had been called up.
Discovery of nuclear fission | Protactinium
Hahn was a Boy Scout fascinated by chemistry, and spent years conducting amateur chemistry experiments, which sometimes caused small explosions and other mishaps. He was inspired in part by reading "The Golden Book of Chemistry Experiments", and tried to collect samples of every element in the periodic table, including the radioactive ones. He later received a merit badge in Atomic Energy and became fascinated with the idea of creating a breeder reactor in his home. Hahn diligently amassed radioactive material by collecting small amounts from household products, such as americium from smoke detectors, thorium from camping lantern mantles, radium from clocks, and tritium from gunsights.
David Hahn | Creation of the neutron source
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. 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. 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.
Otto Hahn | Discovery of nuclear isomerism
Not only Hahn but most of the students, laboratory assistants and technicians had been called up, so she had to do everything herself, aided only briefly by Hahn when he came home on leave. By December 1917 she was able to isolate the substance, and after further work was able to prove that it was indeed the missing isotope. She submitted their findings for publication in March 1918. 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.
Otto Hahn | Discovery of protactinium
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.
Otto Hahn | Discovery of radioactive recoil
Hahn, initially, was not, but he changed his mind when Aristid von Grosse suggested that what Fermi had found was an isotope of protactinium. "The only question", Hahn later wrote, "seemed to be whether Fermi had found isotopes of transuranian elements, or isotopes of the next-lower element, protactinium. At that time Lise Meitner and I decided to repeat Fermi's experiments in order to find out whether the 13-minute isotope was a protactinium isotope or not. It was a logical decision, having been the discoverers of protactinium." Between 1934 and 1938, Hahn, Meitner and Strassmann found a great number of radioactive transmutation products, all of which they regarded as transuranic.
Otto Hahn | Discovery of nuclear fission
It was not long before Fajans and Oswald Helmuth Göhring discovered it as a decay product of a beta-emitting product of thorium. Based on the radioactive displacement law of Fajans and Soddy, this was an isotope of the missing element, which they named "brevium" after its short half-life. However, it was a beta emitter, and therefore could not be the mother isotope of actinium. This had to be another isotope. Two scientists at the Kaiser Wilhelm Institute (KWI) in Berlin-Dahlem took up the challenge of finding the missing isotope. Otto Hahn had graduated from the University of Marburg as an organic chemist, but had been a post-doctoral researcher at University College London under Sir William Ramsay, and under Rutherford at McGill University, where he had studied radioactive isotopes.
Discovery of nuclear fission | Protactinium
His wife Edith only survived him by a fortnight. He was buried in the Stadtfriedhof in Göttingen. The day after his death, the Max Planck Society published the following obituary notice in all the major newspapers in Germany, Austria, and Switzerland: Fritz Strassmann wrote: Otto Robert Frisch recalled:
Otto Hahn | Death
He found that the proportion of uranium X to uranium Z extracted from several kilograms of uranyl nitrate remained constant over time, strongly indicating that uranium X was the mother of uranium Z. To prove this, Hahn obtained a hundred kilograms of uranyl nitrate; separating the uranium X from it took weeks. He found that the half life of the parent of uranium Z differed from the known 24 day half life of uranium X1 by no more than two or three days, but was unable to get a more accurate value. Hahn concluded that uranium Z and uranium X2 were both the same isotope of protactinium (protactinium-234), and they both decayed into uranium II (uranium-234), but with different half lives.
Otto Hahn | Discovery of nuclear isomerism
In 1906, Hahn returned to Germany, where Fischer placed at his disposal a former woodworking shop ("Holzwerkstatt") in the basement of the Chemical Institute to use as a laboratory. Hahn equipped it with electroscopes to measure alpha and beta particles and gamma rays. In Montreal these had been made from discarded coffee tins; Hahn made the ones in Berlin from brass, with aluminium strips insulated with amber. These were charged with hard rubber sticks that he rubbed then against the sleeves of his suit. It was not possible to conduct research in the wood shop, but Alfred Stock, the head of the inorganic chemistry department, let Hahn use a space in one of his two private laboratories.
Otto Hahn | Discovery of mesothorium I
In December 1938, German chemist Otto Hahn and his assistant Fritz Strassmann sent a manuscript to the German science journal "Naturwissenschaften" ("Natural Sciences") reporting that they had detected and identified the element barium after bombarding uranium with neutrons. Their article was published on 6 January 1939. On 19 December 1938, eighteen days before the publication, Otto Hahn communicated these results and his conclusion of a "bursting" of the uranium nucleus in a letter to his colleague and friend Lise Meitner, who had fled Germany in July to the Netherlands and then to Sweden. Meitner and her nephew Otto Robert Frisch confirmed Hahn's conclusion of a "bursting" and correctly interpreted the results as "nuclear fission" – a term coined by Frisch.
German nuclear weapons program | Discovery of nuclear fission
Enrico Fermi and his colleagues in Rome picked up on this idea, and began irradiating elements with neutrons. The radioactive displacement law of Fajans and Soddy said that beta decay causes isotopes to move one element up on the periodic table, and alpha decay causes them to move two down. When Fermi's group bombarded uranium atoms with neutrons, they found a complex mix of half lives. Fermi therefore concluded that the new elements with atomic numbers greater than 92 (known as transuranium elements) had been created. Meitner and Hahn had not collaborated for many years, but Meitner was eager to investigate Fermi's results.
Otto Hahn | Discovery of nuclear fission
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.
Otto Hahn | The Nobel Prize in Chemistry 1944
""The award of the Otto Hahn Peace Medal has given me great joy and satisfaction, particularly because it is linked with the name of this great man, a great scientist, and a modest human being who was ready to help other people at all times, and who has always been a role model for me."" (Prof. Dr. h.c. Simon Wiesenthal, Vienna, 1991). ""Ever since my early youth, I have admired Otto Hahn as a scientist and a human being. The reason for Hahn's peace work was simply that, knowing more than other citizens about atomic weapons, he felt it his duty to speak about this issue that was so crucial for mankind.
Otto Hahn Peace Medal | Statements by prizewinners
Hahn therefore became the sole recipient of the 1944 Nobel Prize for Chemistry. The invitation to attend the Nobel festivities was transmitted via the British Embassy in Stockholm. 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.
Otto Hahn | The Nobel Prize in Chemistry 1944
The Otto Hahn Prize is awarded biennially jointly by the Society of German Chemists (), the German Physical Society () and the city of Frankfurt am Main for outstanding achievement in the field of chemistry, physics or applied engineering science. It was established in 2005 by the merger of the previous Otto Hahn Prize for Chemistry and Physics and the Otto Hahn Prize of the City of Frankfurt am Main. The award named after the German nuclear scientist and Nobel laureate Otto Hahn and consists of a gold medal and a prize of 50,000 euros. It is awarded alternatively for Chemistry and Physics.
Otto Hahn Prize | Introduction
In 1938, the German chemist Otto Hahn, a student of Rutherford, directed neutrons onto uranium atoms expecting to get transuranium elements. Instead, his chemical experiments showed barium as a product. A year later, Lise Meitner and her nephew Otto Frisch verified that Hahn's result were the first experimental "nuclear fission". In 1944, Hahn received the Nobel Prize in Chemistry. Despite Hahn's efforts, the contributions of Meitner and Frisch were not recognized. In the 1950s, the development of improved particle accelerators and particle detectors allowed scientists to study the impacts of atoms moving at high energies. Neutrons and protons were found to be hadrons, or composites of smaller particles called quarks.
Atom | Fission, high-energy physics and condensed matter
At this point, Hahn decided that he first needed to know more about the subject, so he wrote to the leading expert on the field, Ernest Rutherford. Rutherford agreed to take Hahn on as an assistant, and Hahn's parents undertook to pay Hahn's expenses. From September 1905 until mid-1906, Hahn worked with Rutherford's group in the basement of the Macdonald Physics Building at McGill University in Montreal. There was some scepticism about the existence of radiothorium, which Bertram Boltwood memorably described as a compound of thorium X and stupidity. Boltwood was soon convinced that it did exist, although he and Hahn differed on what its half life was.
Otto Hahn | Discovery of radio thorium, and other "new elements"
Hahn refused medical evaluation for radiation exposure. EPA scientists believe that Hahn's life expectancy may have been greatly shortened by his exposure to radioactivity, particularly since he spent long periods in the small, enclosed shed with large amounts of radioactive material and only minimal safety precautions, but he refused their recommendation that he be examined at the Enrico Fermi Nuclear Generating Station.
David Hahn | Creation of the neutron source
Initially, Hahn was not interested, but von Grosse's mention of protactinium changed his mind. "The only question", Hahn later wrote, "seemed to be whether Fermi had found isotopes of transuranian elements, or isotopes of the next-lower element, protactinium. At that time Lise Meitner and I decided to repeat Fermi's experiments in order to find out whether the 13-minute isotope was a protactinium isotope or not. It was a logical decision, having been the discoverers of protactinium." Hahn and Meitner were joined by Fritz Strassmann. Strassmann had received his doctorate in analytical chemistry from the Technical University of Hannover in 1929, and had come to the Kaiser Wilhelm Institute for Chemistry to study under Hahn, believing that this would improve his employment prospects.
Discovery of nuclear fission | Objections
The Otto Hahn Medal () is awarded by the Max Planck Society to young scientists and researchers in both the natural and social sciences. The prestigious award takes its name from the German chemist and Nobel Prize laureate Otto Hahn, who served as the first president of the Max Planck Society from 1948 to 1960. The medal is awarded annually to a maximum of thirty junior scientists in recognition of outstanding scientific achievement. Up to ten awardees are selected in each of three thematized sections: 1) Biological-Medical, 2) Chemical-Physical-Engineering, and 3) Social Science-Humanities. It is accompanied by a monetary award of €7,500.
Otto Hahn Medal | Introduction
They identified ten different half lives, with varying degrees of certainty. To account for them, Meitner had to hypothesise a new class of reaction and the alpha decay of uranium, neither of which had ever been reported before, and for which physical evidence was lacking. Hahn and Strassmann refined their chemical procedures, while Meitner devised new experiments to shine more light on the reaction processes. 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. 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"); Meitner was increasingly uncertain.
Otto Hahn | Discovery of nuclear fission
But I believe that Frisch and I contributed something not insignificant to the clarification of the process of uranium fission—how it originates and that it produces so much energy and that was something very remote to Hahn." Hahn's receipt of a Nobel Prize was long expected. Both he and Meitner had been nominated for both the chemistry and the physics prizes several times even before the discovery of nuclear fission. According to the Nobel Prize archive, she was nominated 19 times for Nobel Prize in Chemistry between 1924 and 1948, and 29 times for Nobel Prize in Physics between 1937 and 1965.
Lise Meitner | Nobel Prize for nuclear fission
Hahn reported to the HWA on the progress of his research. Together with his assistants, Hans-Joachim Born, Siegfried Flügge, Hans Götte, Walter Seelmann-Eggebert and Strassmann, he catalogued about one hundred fission product isotopes. They also investigated means of isotope separation; the chemistry of element 93; and methods for purifying uranium oxides and salts. On the night of 15 February 1944, the Kaiser Wilhelm Institute for Chemistry building was struck by a bomb. Hahn's office was destroyed, along with his correspondence with Rutherford and other researchers, and many of his personal possessions. The office was the intended target of the raid, which had been ordered by Brigadier General Leslie Groves, the director of the Manhattan Project, in the hope of disrupting the German uranium project.
Otto Hahn | World War II
Hahn was still there when his Nobel Prize was announced in November 1945. The Farm Hall scientists would spend the rest of their lives attempting to rehabilitate the image of German science that had been tarnished by the Nazi period. Inconvenient details like the thousands of female slave labourers from Sachsenhausen concentration camp who mined uranium ore for their experiments were swept under the rug. For Hahn, this necessarily involved asserting his claim of the discovery of fission for himself, for chemistry, and for Germany. He used his Nobel Prize acceptance speech to assert this narrative. Hahn's message resonated strongly in Germany, where he was revered as the proverbial good German, a decent man who had been a staunch opponent of the Nazi regime, but had remained in Germany where he had pursued pure science.
Discovery of nuclear fission | In history and memory
Source: DGVN (in German)
Otto Hahn Peace Medal | Previous prizewinners
Despite the many honours that Meitner received in her lifetime, she did not receive the Nobel Prize while it was awarded to Otto Hahn for the discovery of nuclear fission. On 15 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". Meitner was the one who told Hahn and Strassman to test their radium in more detail and it was she who told Hahn that it was possible for the nucleus of uranium to disintegrate. Without these contributions of Meitner, Hahn would not have found that the uranium nucleus can split in half.
Lise Meitner | Nobel Prize for nuclear fission
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. In 1966, Glenn T. Seaborg, co-discoverer of many transuranium elements, wrote about this book as follows:
Otto Hahn | "Applied Radiochemistry"
Medalists are awarded during a ceremony at the General Meeting of the Max Planck Society, taking place annually in alternating locales in Germany.
Otto Hahn Medal | Introduction
Fajans agreed to Meitner naming the element protoactinmium, and assigning it the chemical symbol Pa. In June 1918, Soddy and John Cranston announced that they had extracted a sample of the isotope, but unlike Meitner were unable to describe its characteristics. They acknowledged Meitner's priority, and agreed to the name. 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.
Otto Hahn | Discovery of protactinium
Both Hahn and Meitner had been nominated for the chemistry and the physics Nobel Prizes many times even before the discovery of nuclear fission for their work on radioactive isotopes and protactinium. Several more nominations followed for the discovery of fission between 1940 and 1943. Nobel Prize nominations were vetted by committees of five, one for each award. Although both 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 in 1944. The committee received reports from Theodor Svedberg in 1941 and in 1942.
Discovery of nuclear fission | Nobel Prize
In 1906, he returned to Germany, where he became an assistant to Emil Fischer at the University of Berlin. At McGill he had become accustomed to working closely with a physicist, so he teamed up with Lise Meitner, who had received her doctorate from the University of Vienna in 1906, and had then moved to Berlin to study physics under Max Planck at the Friedrich-Wilhelms-Universität. Meitner found Hahn, who was her own age, less intimidating than older, more distinguished colleagues. Hahn and Meitner moved to the recently established Kaiser Wilhelm Institute for Chemistry in 1913, and by 1920 had become the heads of their own laboratories there, with their own students, research programs and equipment.
Discovery of nuclear fission | Protactinium
These chemists were impressed by Hahn's work, but felt that the experimental work of Meitner and Frisch was not extraordinary. They 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. In 1944 the Nobel Committee for Chemistry voted to recommend that Hahn alone be given the Nobel Prize in Chemistry for 1944. However, Germans had been forbidden to accept Nobel Prizes after the Nobel Peace Prize had been awarded to Carl von Ossietzky in 1936.
Discovery of nuclear fission | Nobel Prize
In 1944, Hahn received the Nobel Prize for Chemistry for the discovery of nuclear fission. Some historians have documented the history of the discovery of nuclear fission and believe Meitner should have been awarded the Nobel Prize with Hahn. Even before it was published, Meitner's and Frisch's interpretation of the work of Hahn and Strassmann crossed the Atlantic Ocean with Niels Bohr, who was to lecture at Princeton University. Isidor Isaac Rabi and Willis Lamb, two Columbia University physicists working at Princeton, heard the news and carried it back to Columbia. Rabi said he told Fermi; Fermi gave credit to Lamb.
G. N. Glasoe | Career
As a consequence, at the end of the war he was arrested by the Allied forces, and was incarcerated in Farm Hall with nine other German scientists, from July 1945 to January 1946.
Otto Hahn | Introduction
The Otto Hahn Peace Medal in Gold is named after the German nuclear chemist and 1944 Nobel Laureate Otto Hahn, an honorary citizen of Berlin. The medal is in memory of his worldwide involvement in the politics of peace and humanitarian causes, in particular since the dropping of the atomic bombs on Hiroshima and Nagasaki in August 1945 by the United States Army Air Forces. It was established by his grandson Dietrich Hahn in 1988 and is awarded by the United Nations Association of Germany (Deutsche Gesellschaft für die Vereinten Nationen, DGVN, Berlin-Brandenburg) to persons or institutions that have rendered ""outstanding services to peace and international understanding"".
Otto Hahn Peace Medal | Introduction
He could make things clear, he had to use his knowledge. And it is why Otto Hahn, with atomic weapons in mind, wrote shortly before his death of the 'necessity of world peace'."" (Prof. Dr. Sir Karl R. Popper, Kenley, 1993). ""Otto Hahn held a particular attraction for us younger people after the war. In his commitment to the promotion of free scientific enquiry, as well as in his efforts to persuade scientists to recognize their responsibility for shaping the contemporary world and the future, we found something which we could identify. And when in the fifties he came out so strongly and impressively against the misuse of nuclear science for aggressive purposes, we looked upon him as an example to us all.
Otto Hahn Peace Medal | Statements by prizewinners
Hahn and Strassmann at the Kaiser Wilhelm Institute for Chemistry in Berlin bombarded uranium with slow neutrons, and discovered that barium had been produced. They reported their findings by mail to Meitner in Sweden, who a few months earlier had fled Nazi Germany. Meitner and her nephew Frisch theorised, and then proved, that the uranium nucleus had been split, and published their findings in "Nature". Meitner calculated that the energy released by each disintegration was approximately 200 megaelectronvolts, and Frisch observed this. By analogy with the division of biological cells, he named the process "fission". Hahn was awarded the 1944 Nobel Prize in Chemistry for the discovery.
Discovery of nuclear fission | Introduction
During the Christmas holiday in 1938 he visited his aunt Lise Meitner in Kungälv. While there she received the news that Otto Hahn and Fritz Strassmann in Berlin had discovered that the collision of a neutron with a uranium nucleus produced the element barium as one of its byproducts. Hahn, in a letter to Meitner, called this new reaction a "bursting" of the uranium nucleus. Frisch and Meitner hypothesized that the uranium nucleus had split in two, explained the process, and estimated the energy released, and Frisch coined the term fission to describe it. Political restraints of the Nazi era forced the team of Hahn and that of Frisch and Meitner (both of whom were Jewish) to publish separately.
Otto Robert Frisch | Nuclear fission
Hahn started to diligently collect radioactive materials and substances from household items and products. His initial sources were everyday objects which happened to be radioactive in part. This included americium from smoke detectors, thorium from the mantles of gas lanterns, radium from antique clocks, and tritium from the sights of guns. Hahn's "reactor" was a bored-out block of lead that was mixed with lithium from roughly $1,000 worth of batteries to purify the thorium. However, he began to obtain radioactive items by asking to get them while posing as a scientist or a teacher through letters and phone calls. The neutron source that Hahn had built was capable of emitting radioactivity well over 1,000 times greater than that which tends to permeate through the environment as background radiation to conceal the evidence of his makeshift neutron source by disposing of the materials that made it.
History of the Boy Scouts of America | David Hahn
His achievements have been recognized with the American Nuclear Society's Seaborg Medal and many other awards including the 2018 National Engineering Award from the American Association of Engineering Societies, the 2017 American Nuclear Society Eisenhower Medal, the Navy League of the U.S.'s TR & FD Roosevelt Gold Medal for Science Award in 1996, the AAAS Award for Science Diplomacy, the Leo Szilard Lectureship (APS), the Department of Energy's E.O. Lawrence Award, the LANL Medal, and the Case Western Reserve University Alumni Association Gold Medal and Undergraduate Distinguished Alumni Award. The Secretary of Energy named Hecker, co-recipient of the 2009 Enrico Fermi Award.
Siegfried S. Hecker | Awards
The Kaiser Wilhelm Institute for Chemistry, now under Strassmann, built and renovated new accommodation in Mainz, but work proceeded slowly, and it did not relocate from Tailfingen until 1949. Hahn's insistence on retaining Ernst Telschow as the general secretary nearly caused a rebellion against his presidency. In his efforts to rebuild German science, Hahn was generous in issuing "persilschein" (whitewash certificates), writing one for Gottfried von Droste, who had joined the "Sturmabteilung" (SA) in 1933 and the NSDAP in 1937, and wore his SA uniform at the Kaiser Wilhelm Institute for Chemistry, and for Heinrich Hörlein and Fritz ter Meer from IG Farben.
Otto Hahn | Founder and President of the Max Planck Society
In 1972, after four years of operation, her reactor was refuelled. She had covered 250,000 nautical miles (463,000 km) on 22 kilograms of uranium.
Otto Hahn (ship) | History
Rubens said that he would be happy for her to work in his laboratory. He also added that Otto Hahn at the chemistry institute was looking for a physicist to collaborate with. A few minutes later she was introduced to Hahn. He had studied radioactive substances under Sir William Ramsay, and in Montreal under Rutherford, and was already credited with the discovery of what were then thought to be several new radioactive elements. (In fact, they were isotopes of known elements, but the concept of an isotope, along with the term, was only propounded by Frederick Soddy in 1913.) Hahn was the same age as herself, and she noted his informal and approachable manner.
Lise Meitner | Friedrich Wilhelm University
Meitner's diploma bore the words: "For pioneering research in the naturally occurring radioactivities and extensive experimental studies leading to the discovery of fission". Hahn's diploma was slightly different: "For pioneering research in the naturally occurring radioactivities and extensive experimental studies culminating in the discovery of fission." Hahn and Strassmann were present, but Meitner was too ill to attend, so Frisch accepted the award on her behalf.
Discovery of nuclear fission | In history and memory
The international reaction was encouraging. The following year he initiated and organized the Mainau Declaration of 1955, in which he and a number of international Nobel Prize-winners called attention to the dangers of atomic weapons and warned the nations of the world urgently against the use of "force as a final resort", and which was issued a week after the similar Russell-Einstein Manifesto. In 1956, Hahn repeated his appeal with the signature of 52 of his Nobel colleagues from all parts of the world. Hahn was also instrumental in and one of the authors of the Göttingen Manifesto of 13 April 1957, in which, together with 17 leading German atomic scientists, he protested against a proposed nuclear arming of the West German armed forces ("Bundeswehr").
Otto Hahn | Spokesman for social responsibility
He won the 1921 Nobel Prize in Chemistry in part for his work on isotopes.
Isotope | Radioactive isotopes
Albert Speer, the Reich Minister of Armaments and War Production, arranged for the institute to move to Tailfingen in southern Germany. All work in Berlin ceased by July. Hahn and his family moved to the house of a textile manufacturer there. 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.
Otto Hahn | World War II
Hahn purchased two milligrams of radium from Friedrich Oskar Giesel, the discoverer of emanium (radon), for 100 marks a milligram, and obtained thorium for free from Otto Knöfler, whose Berlin firm was a major producer of thorium products. In the space of a few months Hahn discovered mesothorium I (radium-228), mesothorium II (actinium-228), and – independently from Boltwood – the mother substance of radium, ionium (later identified as thorium-230). In subsequent years, mesothorium I assumed great importance because, like radium-226 (discovered by Pierre and Marie Curie), it was ideally suited for use in medical radiation treatment, but cost only half as much to manufacture.
Otto Hahn | Discovery of mesothorium I
Aristid von Grosse was a German nuclear chemist. During his work with Otto Hahn, he got access to waste material from radium production, and with this starting material he was able in 1927 to isolate protactinium oxide and was later able to produce metallic protactinium by decomposition of protactinium iodide. From 1948 to 1969, he was president of the Research Institute of Temple University and was later affiliated with the laboratories of the Franklin Institute in Philadelphia until his retirement in 1979. In 1971, he received a United States Atomic Energy Commission award in recognition of his "outstanding contributions to the development of nuclear energy." Aristid was born in Riga in January 1905 and moved to the United States in 1930.
Aristid von Grosse | Introduction
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—for other reasons. Another physicist with a Jewish wife was . 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.
Otto Hahn | World War II
While at Vanderbilt, Slack maintained ties with his "alma mater" Columbia University. In December 1938, the German chemists Otto Hahn and Fritz Strassmann sent a manuscript to "Naturwissenschaften" reporting they had detected the element barium after bombarding uranium with neutrons; they communicated these results to Lise Meitner. Meitner, and her nephew Otto Robert Frisch, who correctly interpreted these results as being nuclear fission. Frisch confirmed this experimentally on 13 January 1939. In 1944, Hahn received the Nobel Prize for Chemistry for the discovery of nuclear fission. Some historians have documented the history of the discovery of nuclear fission and believe Meitner should have been awarded the Nobel Prize with Hahn.
Francis G. Slack | Career
Otto Hahn, one of those who were grateful that Germany had not built a bomb, chided those who had worked on the German project, saying "If the Americans have a uranium bomb then you're all second-raters."
Operation Epsilon | Farm Hall transcripts
He enjoyed the work and the people so much that he stayed on after his stipend expired in 1932. After the Nazi Party came to power in Germany in 1933, he declined a lucrative offer of employment because it required political training and Nazi Party membership, and he resigned from the Society of German Chemists when it became part of the Nazi German Labour Front. As a result, he could neither work in the chemical industry nor receive his habilitation, which was required to become an independent researcher in Germany. Meitner persuaded Hahn to hire Strassmann using money from the director's special circumstances fund.
Discovery of nuclear fission | Objections
Between 1939 and 1961, he received honorary doctorate degrees from nine universities in Europe and America.
Otto Struve | Awards and honors
In mid-1936, Heisenberg presented his theory of cosmic-ray showers in two papers. Four more papers appeared in the next two years. In December 1938, the German chemists Otto Hahn and Fritz Strassmann sent a manuscript to "The Natural Sciences" reporting they had detected the element barium after bombarding uranium with neutrons and Otto Hahn concluded a "bursting" of the uranium nucleus; simultaneously, Hahn communicated these results to his friend Lise Meitner, who had in July of that year fled to the Netherlands and then went to Sweden. Meitner, and her nephew Otto Robert Frisch, correctly interpreted Hahn's and Strassmann's results as being nuclear fission.
Werner Heisenberg | Pre-war work on physics
That summer Hahn was accidentally poisoned by phosgene while testing a new model gas mask. At the end of the war he was in the field in mufti on a secret mission to test a pot that heated and released a cloud of arsenicals.
Otto Hahn | World War I
Wichterle was a member of a number of foreign academies of science, he received many awards and honorary doctorates from several universities.
Otto Wichterle | Other achievements
On 24 April 1939, Paul Harteck and his assistant, Wilhelm Groth, had written to Reich Ministry of War, alerting it to the possibility of the development of an atomic bomb. In response, the Army Weapons Branch (HWA) had established a physics section under nuclear physicist Kurt Diebner. After World War II broke out on 1 September 1939, the HWA moved to control the German nuclear weapons program. From then on, Hahn was participated in a ceaseless series of meetings related to the project. After the Director of the Kaiser Wilhelm Institute for Physics, Peter Debye, left for the United States in 1940 and never returned, Diebner was installed as its director.
Otto Hahn | World War II
Hanle and Joos would soon be part of the impetus to initiate the German nuclear energy project, shortly after Hanle went to Göttingen. From 1937 to 1941, Hanle was again at the University of Göttingen. In December 1938, the German chemists Otto Hahn and Fritz Strassmann sent a manuscript to "Naturwissenschaften" reporting they had detected the element barium after bombarding uranium with neutrons; simultaneously, they communicated these results to Lise Meitner, who had in July of that year fled to The Netherlands and then went to Sweden. Meitner, and her nephew Otto Robert Frisch, correctly interpreted these results as being nuclear fission.
Wilhelm Hanle | Career
The incident received scant media attention at the time, but was widely disseminated after writer Ken Silverstein published an article about the incident in "Harper's Magazine" in 1998. In 2004 he expanded it into a book, "The Radioactive Boy Scout", which was optioned for a feature film in 2016. In 1999, University of Chicago physics majors Justin Kasper and Fred Niell, as part of a scavenger hunt that had as one of its items "a breeder reactor built in a shed," successfully built a similar nuclear reactor that produced trace amounts of plutonium. In the "" episode "", the character Lawrence Wagner is based on Hahn.
David Hahn | In popular culture
His body reflected neutrons back into the stack. Out of the corner of his eye he saw that the red lamps that flickered intermittently when neutrons were being emitted, were 'glowing continuously'. Realizing what was happening, Frisch quickly scattered the bars with his hand. Later he calculated that the radiation dose was "quite harmless" but that if he "had hesitated for another two seconds before removing the material ... the dose would have been fatal". "In two seconds he received, by the generous standards of the time, a full day's permissible dose of neutron radiation." In this way his experiments determined the exact masses of uranium required to fire the Little Boy bomb over Hiroshima.
Otto Robert Frisch | Manhattan Project
He received the Nobel Prize in Chemistry in 1921 and the same year he was elected member of the International Atomic Weights Committee. A small crater on the far side of the Moon as well as the radioactive uranium mineral soddyite are named after him.
Frederick Soddy | Honours and awards
He completed his one-year military service (instead of the usual two because he had a doctorate) in the 81st Infantry Regiment, but unlike his brothers, did not apply for a commission. He then returned to the University of Marburg, where he worked for two years as assistant to his doctoral supervisor, "Geheimrat" Professor Theodor Zincke.
Otto Hahn | Early life
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". 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.
Otto Hahn | Death
In 1987, his centenary year, a birthday conference was given in his honor at the University of Erlangen. He was awarded honorary doctorates from the University of Bonn, the University of Nantes and the University of Würzburg.
Otto Haupt | Awards and honors
Their only child, , 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 Pletz. They left a fourteen-year-old son, Dietrich Hahn.
Otto Hahn | Marriage to Edith Junghans
Hahn's paper described the experiment and the finding of the barium byproduct. Meitner's and Frisch's paper explained the physics behind the phenomenon. Frisch went back to Copenhagen, where he was quickly able to isolate the pieces produced by fission reactions. As Frisch himself later recalled, a fundamental idea of the direct experimental proof of the nuclear fission was suggested to him by George Placzek. Many feel that Meitner and Frisch deserved Nobel Prize recognition for their contributions to understanding fission.
Otto Robert Frisch | Nuclear fission
McCoy did considerable work with uranium and thorium, which at the time were believed to be rare earths. McCoy's research contributed to the understanding of relationships among elements in the period table. In 1904, he independently demonstrated spontaneous transmutation of radium from uranium. As well, McCoy and William H. Ross clearly identified what came to be known as isotopes as chemically inseparable substances, a realization that enabled researchers to simplify models of the periodic table. Studying what would become known as the thorium group, McCoy and Ross verified Otto Hahns prediction of "mesothorium", an isotope of radium.
Herbert Newby McCoy | Career