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111-501: Hans Albrecht Bethe ( German: [ˈhans ˈbeːtə] ; July 2, 1906 – March 6, 2005) was a German-born American physicist who made major contributions to nuclear physics , astrophysics , quantum electrodynamics and solid-state physics , and received the Nobel Prize in Physics in 1967 for his work on the theory of stellar nucleosynthesis . For most of his career, Bethe was

222-573: A Jewish background, Bethe was raised Protestant , like his father; and he became an atheist later in life. His father accepted a position as professor and director of the Institute of Physiology at the University of Kiel in 1912, and the family moved into the director's apartment at the institute. Initially, he was schooled privately by a professional teacher as part of a group of eight girls and boys. The family moved again in 1915 when his father became

333-586: A cyclotron at Cornell. To complete the team, Cornell needed an experimentalist, and, on the advice of Bethe and Livingston, recruited Robert Bacher . Bethe received requests to visit Columbia University from Isidor Isaac Rabi , Princeton University from Edward Condon , University of Rochester from Lee DuBridge , Purdue University from Karl Lark-Horovitz , the University of Illinois at Urbana–Champaign from Francis Wheeler Loomis , and Harvard University from John Hasbrouck Van Vleck . Gibbs moved to prevent Bethe from being poached by having him appointed as

444-700: A master's degree like MSc, MPhil, MPhys or MSci. For research-oriented careers, students work toward a doctoral degree specializing in a particular field. Fields of specialization include experimental and theoretical astrophysics , atomic physics , biological physics , chemical physics , condensed matter physics , cosmology , geophysics , gravitational physics , material science , medical physics , microelectronics , molecular physics , nuclear physics , optics , particle physics , plasma physics , quantum information science , and radiophysics . The three major employers of career physicists are academic institutions, laboratories, and private industries, with

555-597: A " Begabtenprüfung " ("test of aptitude") are also eligible. Students from other countries who hold a high school leaving certificate that is not counted as being equivalent to the Abitur (such as the American high school diploma) and who do well enough on the ACT or SAT test, may also enter German universities. A person who does not hold the Abitur and did not take an aptitude test may still be admitted to university by completing at least

666-544: A German Fachoberschule , a vocational high school, also introduced in the 1970s. The term Notabitur ('emergency Abitur ' ) describes a qualification used only during World War I and World War II . It was granted to male German Gymnasium students who voluntarily enlisted for military service before graduation as well as young women who were evacuated from the major cities before they could complete their Gymnasium education as planned (approximately three to five million children and teenagers had to be evacuated during

777-473: A Gymnasium, while 40,000 received it at a different kind of school, most notably at Gesamtschulen . If those who obtain the Fachhochschulreife (144,399 in 2012) are also added, then the total of those who obtained the right to study at a university or a Fachhochschule is 395,000 (2021). Until the eighteenth century, every German university had its own entrance examination. In 1788 Prussia introduced

888-473: A few months before, the Korean war had broken out, and for the first time I saw direct confrontation with the communists . It was too disturbing. The cold war looked as if it were about to get hot. I knew then I had to reverse my earlier position. If I did not work on the bomb, somebody else would—and I had thought if I were around Los Alamos I might still be a force for disarmament. So I agreed to join in developing

999-451: A formula for calculating the bomb's explosive yield. After August 1944, when the laboratory was reorganized and reoriented to solve the problem of the implosion of the plutonium bomb, Bethe spent much of his time studying the hydrodynamic aspects of implosion, a job that he continued into 1944. In 1945, he worked on the neutron initiator, and later, on radiation propagation from an exploding atomic bomb. The Trinity nuclear test validated

1110-513: A letter endorsing John Kerry for President of the United States as someone who would "restore science to its appropriate place in government". Physicist Physicists can apply their knowledge towards solving practical problems or to developing new technologies (also known as applied physics or engineering physics ). The study and practice of physics is based on an intellectual ladder of discoveries and insights from ancient times to

1221-452: A minimum, the owner must possess a three-year bachelors or equivalent degree in physics or a related field and an additional minimum of six years' experience in a physics-related activity; or an Honor or equivalent degree in physics or a related field and an additional minimum of five years' experience in a physics-related activity; or master or equivalent degree in physics or a related field and an additional minimum of three years' experience in

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1332-505: A physics-related activity; a Doctorate or equivalent degree in Physics or a related field; or training or experience which, in the opinion of the Council, is equivalent to any of the above. Physicists may be a member of a physical society of a country or region. Physical societies commonly publish scientific journals, organize physics conferences and award prizes for contributions to the field of physics. Some examples of physical societies are

1443-534: A position as lecturer at the University of Manchester for a year through Sommerfeld's connection to William Lawrence Bragg . He moved in with his friend Rudolf Peierls and Peierls' wife Genia. Peierls was a fellow German physicist who had also been barred from academic positions in Germany because he was Jewish. This meant that Bethe had someone to speak to in German and he did not have to eat English food. Their relationship

1554-668: A private, coeducational boarding school . He attended the Goethe-Gymnasium again for his final three years of secondary schooling, from 1922 to 1924. Having passed his Abitur , Bethe entered the University of Frankfurt in 1924. He decided to major in chemistry . The instruction in physics was poor, and while there were distinguished mathematicians in Frankfurt such as Carl Ludwig Siegel and Otto Szász , Bethe disliked their approaches, which presented mathematics without reference to

1665-416: A professional practice examination must also be passed. An exemption can be granted to a candidate that has practiced physics for at least seven years and provide a detailed description of their professional accomplishments which clearly demonstrate that the exam is not necessary. Work experience will be considered physics-related if it uses physics directly or significantly uses the modes of thought (such as

1776-577: A professor at Cornell University . During World War II, he was head of the Theoretical Division at the secret Los Alamos laboratory that developed the first atomic bombs . There he played a key role in calculating the critical mass of the weapons and developing the theory behind the implosion method used in both the Trinity test and the " Fat Man " weapon dropped on Nagasaki in August 1945 . After

1887-475: A regular assistant professor in 1936, with an assurance that promotion to professor would soon follow. Together with Bacher and Livingston, Bethe published a series of three articles, which summarized most of what was known on the subject of nuclear physics until that time, an account that became known informally as "Bethe's Bible". It remained the standard work on the subject for many years. In this account, he also continued where others left off, filling in gaps in

1998-550: A simple civil ceremony. She had emigrated to the United States and was a student at Duke University and they met while Bethe was lecturing there in 1937. They had two children, Henry and Monica. (Henry was a contract bridge expert and former husband of Kitty Munson Cooper .) Bethe became a naturalized citizen of the United States in March 1941. Writing to Sommerfeld in 1947, Bethe confided that "I am much more at home in America than I ever

2109-468: A solution for the case where there was an infinite hard-core potential. Then, working with Baird Brandow and Albert Petschek, he came up with an approximation that converted the scattering equation into an easily solved differential equation . This then led him to the Bethe-Faddeev equation, a generalisation of Ludvig Faddeev 's approach to three-body scattering. He then used these techniques to examine

2220-434: A specified range of majors, depending on the specific subjects covered in his Fachabitur examinations. But the graduate is allowed to study for all majors at a Fachhochschule (University of Applied Sciences, in some ways comparable to polytechnics ). Today, the school leaving certificate is called fachgebundenes Abitur ('restricted subject Abitur ' ). Now the term Fachabitur is used in most parts of Germany for

2331-446: A starting point, Sommerfeld suggested Paul Ewald 's 1914 paper on X-ray diffraction in crystals. Bethe later recalled that he became too ambitious, and, in pursuit of greater accuracy, his calculations became unnecessarily complicated. When he met Wolfgang Pauli for the first time, Pauli told him: "After Sommerfeld's tales about you, I had expected much better from you than your thesis." "I guess from Pauli," Bethe later recalled, "that

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2442-626: A strong advocate for electricity from nuclear energy, which he described in 1977 as "a necessity, not merely an option." In the 1980s he and other physicists opposed the Strategic Defense Initiative missile system conceived by the Ronald Reagan administration. In 1995, at the age of 88, Bethe wrote an open letter calling on all scientists to "cease and desist" from working on any aspect of nuclear weapons development and manufacture. In 2004, he joined 47 other Nobel laureates in signing

2553-507: A value for the Lamb shift of 1040 MHz, extremely close to that obtained experimentally by Lamb and Retherford. His paper, published in the Physical Review in August 1947, was only three pages long and contained just twelve mathematical equations, but was enormously influential. It had been presumed that the infinities indicated that QED was fundamentally flawed, and that a new, radical theory

2664-894: Is also an all India level examination conducted by Central Board of Secondary education CBSE the certification is known as Higher Secondary Certificate (HSC). During the final examinations ( Abiturprüfungen ), students are tested in four or five subjects (at least one of which is oral). Procedures vary by state . Although some tested subjects are chosen by the student, three areas must be covered: Occasionally, schools (especially berufsorientierte Gymnasien ) offer vocational subjects such as pedagogy , business informatics , biotechnology and mechanical engineering . Final exams are usually taken from March to May or June. Each written basic-level examination takes about three hours; advanced-level examinations take four-and-a-half hours, and written exams are in essay format. Oral examinations last about 20 min. Papers are graded by at least two teachers at

2775-601: Is called the Victorian Certificate of Education (VCE); in New South Wales it is called the Higher Schools Certificate (HSC). In India various states name it differently. Each Indian state has its own examination board, some individual states having their own entrance test system. Passing the specified examination qualifies the student to enter into undergraduate program in a university. For example, in

2886-566: Is known today as the Bethe formula . He submitted this paper for his habilitation in 1930. Sommerfeld recommended Bethe for a Rockefeller Foundation Travelling Scholarship in 1929. This provided $ 150 a month (about $ 3,000 in 2023 dollars) to study abroad. In 1930, Bethe chose to do postdoctoral work at the Cavendish Laboratory at the University of Cambridge in England, where he worked under

2997-600: Is offered at schools outside Germany that are accredited by the German government. The five Abitur exams (three written exams and two oral exams) are in the following subjects: German literature, European history or economics or mathematics or a natural science or a language. In February of senior year (grade 12), all students take the written examinations for the German International Abitur in three subjects including German. In late spring, students have mandatory oral examinations in two subjects, which are overseen by

3108-536: Is the Nobel Prize in Physics , awarded since 1901 by the Royal Swedish Academy of Sciences . National physical societies have many prizes and awards for professional recognition. In the case of the American Physical Society , as of 2023, there are 25 separate prizes and 33 separate awards in the field. Chartered Physicist (CPhys) is a chartered status and a professional qualification awarded by

3219-700: Is the " apolytirion " (a kind of high school diploma); in Malta it is the Matriculation Certificate (MATSEC), in Hungary it is called "Érettségi Bizonyítvány" which translates to Matriculation Certificate. In Australia, the graduation certificate awarded to high school students is the Senior Secondary Certificate of Education (SSCE). However, the name of the SSCE varies from state to state. In Victoria, it

3330-516: The Abiturreglement , a law, for the first time within Germany, establishing the Abitur as an official qualification. It was later also established in the other German states. In 1834, it became the only university entrance exam in Prussia, and it remained so in all states of Germany until 1998. Since then, the German state of Hesse allows students with Fachhochschulreife (see below) to study at

3441-647: The Hauptschulabschluss and the Realschulabschluss , do not allow their holders to matriculate at a university. Those granted certificates of Hauptschulabschluss or Realschulabschluss can gain a specialized Fachhochschulreife or an Abitur if they graduate from a Berufsschule and then attend Berufsoberschule or graduate from a Fachoberschule . However, the Abitur is not the only path to university studies, as some universities set up their own entrance examinations. Students who successfully passed

Hans Bethe - Misplaced Pages Continue

3552-639: The Technische Hochschule in Stuttgart . While there, he wrote what he considered to be his greatest paper, Zur Theorie des Durchgangs schneller Korpuskularstrahlen durch Materie ("The Theory of the Passage of Fast Corpuscular Rays Through Matter"). Starting from Max Born 's interpretation of the Schrödinger equation , Bethe produced a simplified formula for collision problems using a Fourier transform , which

3663-499: The Abitur has steadily increased since the 1970s, and younger jobholders are more likely to hold the Abitur than older ones. The percentage of students qualified for tertiary education is still lower than the OECD average. Percentage of students graduating with Abitur or FHR ( Studienberechtigtenquote ): Percentage of 'jobholders' holding Hauptschulabschluss , Realschulabschluss or Abitur in Germany : The International Abitur

3774-461: The Abitur to consist of written exams including at least two foreign languages (almost always Latin and French, the latter sometimes replaced by English). Students, who received the Notabitur during World War II were offered to re-enter school to prepare for and take the exam after the war had ended. Those special Abitur preparation classes were made up of young adults of different age and sex, which

3885-484: The Abitur usually requires a composite score of at least 50%. Students with a score below that minimum fail and do not receive an Abitur . There are some other conditions that the student also has to meet in order to receive the Abitur : taking mandatory courses in selected subject areas, and limits to the number of failing grades in core subjects. Finally, students often have the option of omitting some courses from their composite score if they have taken more courses than

3996-680: The American Physical Society , the Institute of Physics , with the oldest physical society being the German Physical Society . Abitur Abitur ( German: [abiˈtuːɐ̯] ), often shortened colloquially to Abi , is a qualification granted at the end of secondary education in Germany . It is conferred on students who pass their final exams at the end of ISCED 3 , usually after twelve or thirteen years of schooling (see also, for Germany, Abitur after twelve years ). In German,

4107-592: The Bethe-hole directional coupler , which is used in microwave waveguides such as those used in radar sets. In Chicago in June 1942, and then in July at the University of California, Berkeley , he participated in a series of meetings at the invitation of Robert Oppenheimer, which discussed the first designs for the atomic bomb . They went over the preliminary calculations by Robert Serber , Stan Frankel , and others, and discussed

4218-560: The Carnegie Institute and George Washington University 's fourth annual Washington Conference of Theoretical Physics. There were only 34 invited attendees, but they included Gregory Breit , Subrahmanyan Chandrasekhar , George Gamow , Donald Menzel , John von Neumann , Bengt Strömgren , Edward Teller , and Merle Tuve . Bethe initially declined the invitation to attend, because the conference's topic, stellar energy generation , did not interest him, but Teller persuaded him to go. At

4329-636: The Chernobyl disaster , Bethe was part of a committee of experts who analysed the incident. They concluded that the reactor suffered from a fundamentally faulty design and also that human error had contributed significantly to the accident. "My colleagues and I established," he explained "that the Chernobyl disaster tells us about the deficiencies of the Soviet political and administrative system rather than about problems with nuclear power." Throughout his life Bethe remained

4440-615: The Fachhochschulreife (FHR) . It was introduced in West Germany in the 1970s together with the Fachhochschulen . It enables the graduate to start studying at a Fachhochschule and, in Hesse, also at a university within that state. In the Gymnasiums of some states it is awarded in the year before the Abitur is reached. However, the normal way to obtain Fachhochschulreife is graduation from

4551-522: The H-bomb . It seemed quite logical. But sometimes I wish I were a more consistent idealist . As for his own role in the project and its relation to the dispute over who was responsible for the design , Bethe later said that: After the H-bomb was made, reporters started to call Teller the father of the H-bomb. For the sake of history, I think it is more precise to say that Ulam is the father, because he provided

Hans Bethe - Misplaced Pages Continue

4662-631: The Institute of Physics . It is denoted by the postnominals "CPhys". Achieving chartered status in any profession denotes to the wider community a high level of specialised subject knowledge and professional competence. According to the Institute of Physics, holders of the award of the Chartered Physicist (CPhys) demonstrate the "highest standards of professionalism, up-to-date expertise, quality and safety" along with "the capacity to undertake independent practice and exercise leadership" as well as "commitment to keep pace with advancing knowledge and with

4773-539: The Islamic medieval period , which saw the development of scientific methodology emphasising experimentation , such as the work of Ibn al-Haytham (Alhazen) in the 11th century. The modern scientific worldview and the bulk of physics education can be said to flow from the scientific revolution in Europe, starting with the work of astronomer Nicolaus Copernicus leading to the physics of Galileo Galilei and Johannes Kepler in

4884-766: The University of Bristol for a semester, but Cornell agreed to let him start in the spring of 1935. Before leaving for the United States, he visited the Niels Bohr Institute in Copenhagen in September 1934, where he proposed to Hilde Levi , who accepted. The match was opposed by Bethe's mother, who despite having a Jewish background, did not want him to marry a Jewish woman. A few days before their wedding date in December, Bethe broke off their engagement. Niels Bohr and James Franck were so shocked by this action by Bethe that he

4995-772: The University of Munich , where he could study under Arnold Sommerfeld . Bethe entered the University of Munich in April 1926, where Sommerfeld took him on as a student on Meissner's recommendation. Sommerfeld taught an advanced course on differential equations in physics, which Bethe enjoyed. Because he was such a renowned scholar, Sommerfeld frequently received advance copies of scientific papers, which he put up for discussion at weekly evening seminars. When Bethe arrived, Sommerfeld had just received Erwin Schrödinger 's papers on wave mechanics . For his PhD thesis, Sommerfeld suggested that Bethe examine electron diffraction in crystals . As

5106-474: The fine structure constant from the absolute zero temperature in Celsius units. The paper poked fun at a certain class of papers in theoretical physics of the day, which were purely speculative and based on spurious numerical arguments, such as Arthur Eddington 's attempts to explain the value of the fine structure constant from fundamental quantities in an earlier paper. They were forced to issue an apology. For

5217-452: The handbuch articles occupied most of his time in Rome, but he also co-wrote a paper with Fermi on another new field, quantum electrodynamics , describing the relativistic interactions of charged particles. In 1932, Bethe accepted an appointment as an assistant professor at the University of Tübingen , where Hans Geiger was the professor of experimental physics. One of the first laws passed by

5328-420: The neutron stars , which have densities similar to those of nuclei. Bethe continued to do research on supernovae , neutron stars, black holes , and other problems in theoretical astrophysics into his late nineties. In doing this, he collaborated with Gerald E. Brown of Stony Brook University . In 1978, Brown proposed that they collaborate on supernovae. These were reasonably well understood by this time, but

5439-547: The solar neutrino problem , in which he helped establish the conversion mechanism for electron neutrinos into muon neutrinos proposed by Stanislav Mikheyev , Alexei Smirnov , and Lincoln Wolfenstein to explain a vexing discrepancy between theory and experiment. Bethe argued that physics beyond the Standard Model was required to understand the solar neutrino problem, because it presumed that neutrinos have no mass, and therefore, cannot metamorphosize into each other; whereas

5550-425: The "Foundations of Quantum Mechanics" was the first major physics conference held after the war. It was a chance for American physicists to come together, pick up where they had left off before the war, and establish the direction of post-war research. A major talking point at the conference was the discovery by Willis Lamb and his graduate student, Robert Retherford , shortly before the conference began that one of

5661-522: The "supreme problem-solver of the 20th century". Bethe was born in Strasbourg , which at the time was part of the Reichsland Elsaß-Lothringen , Germany , on July 2, 1906, the only child of Anna (née Kuhn) and Albrecht Bethe, a Privatdozent of physiology at the University of Strasbourg . Although his mother, the daughter of Abraham Kuhn , professor at the University of Strasbourg, had

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5772-755: The 10th grade and doing well on an IQ test (see: Hochbegabtenstudium ). In German, the European Baccalaureate is called europäisches Abitur , and the International Baccalaureate is called internationales Abitur , neither to be confused with the German Abitur . The French-German Baccalaureate is called deutsch-französisches Abitur , and is equivalent both to the German Abitur and to the French Baccalauréat . The term Fachabitur

5883-470: The 1963 Partial Nuclear Test Ban Treaty and 1972 Anti-Ballistic Missile Treaty ( SALT I ). His scientific research never ceased and he was publishing papers well into his nineties, making him one of the few scientists to have published at least one major paper in his field during every decade of his career, which in Bethe's case spanned nearly seventy years. Freeman Dyson , once his doctoral student, called him

5994-579: The 19th century. Many physicists contributed to the development of quantum mechanics in the early-to-mid 20th century. New knowledge in the early 21st century includes a large increase in understanding physical cosmology . The broad and general study of nature, natural philosophy , was divided into several fields in the 19th century, when the concept of "science" received its modern shape. Specific categories emerged, such as "biology" and "biologist", "physics" and "physicist", "chemistry" and "chemist", among other technical fields and titles. The term physicist

6105-511: The Germans were presumably doing it." When Oppenheimer was put in charge of forming a secret weapons design laboratory, Los Alamos , he appointed Bethe director of the T (Theoretical) Division, the laboratory's smallest, but most prestigious division. This move irked the equally qualified, but more difficult to manage Teller and Felix Bloch , who had coveted the job. A series of disagreements between Bethe and Teller between February and June 1944 over

6216-813: The MSW effect required this to occur. Bethe hoped that corroborating evidence would be found by the Sudbury Neutrino Observatory (SNO) in Ontario by his 90th birthday, but he did not get the call from SNO until June 2001, when he was nearly 95. In 1996, Kip Thorne approached Bethe and Brown about LIGO , the Laser Interferometer Gravitational-Wave Observatory designed to detect the gravitational waves from merging neutron stars and black holes. Since Bethe and Brown were good at calculating things that could not be seen, could they look at

6327-479: The New York Academy of Sciences. It won the prize, and Bethe gave Marshak $ 50 finder's fee and used $ 250 to release his mother's furniture. The paper was subsequently published in the Physical Review in March. It was a breakthrough in the understanding of the stars, and would win Bethe the Nobel Prize in Physics in 1967. In 2002, at age 96, Bethe sent a handwritten note to John N. Bahcall congratulating him on

6438-456: The accuracy of T Division's results. When it was detonated in the New Mexico desert on July 16, 1945, Bethe's immediate concern was for its efficient operation, and not its moral implications. He is reported to have commented: "I am not a philosopher." After the war, Bethe argued that a crash project for the hydrogen bomb should not be attempted, although after President Harry Truman announced

6549-399: The approach to problem-solving) developed in your education or experience as a physicist, in all cases regardless of whether the experience is in academia, industry, government, or elsewhere. Management of physics-related work qualifies, and so does appropriate graduate student work. The South African Institute of Physics also delivers a certification of Professional Physicist (Pr.Phys). At

6660-412: The article that nearly any measure taken by the United States would be easily thwarted with the deployment of relatively simple decoys. Bethe was one of the primary voices in the scientific community behind the signing of the 1963 Partial Test Ban Treaty prohibiting further atmospheric testing of nuclear weapons. During the 1980s and 1990s, Bethe campaigned for the peaceful use of nuclear energy . After

6771-411: The bare energy it had when uncoupled from an electromagnetic field, and the self-energy resulting from the electromagnetic coupling, but both were unobservable, since the electromagnetic field cannot be switched off. QED gave infinite values for the self-energies; but the Lamb shift showed that they were both real and finite. Hans Kramers proposed renormalization as a solution, but no one knew how to do

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6882-470: The beginning of such a project and the outbreak of the Korean War , Bethe signed up and played a key role in the weapon's development. Although he saw the project through to its end, Bethe had hoped that it would be impossible to create the hydrogen bomb. He later remarked in 1968 on the apparent contradiction in his stance, having first opposed the development of the weapon and later helping to create it: Just

6993-408: The beginning of the 21st century, many states adopted centralized exams. In 2013, all other states except Rheinland-Pfalz also introduced centralized written exams at least in the core subjects (German, mathematics and the first foreign language, usually English). The exams are structured as follows: The Kultusministerkonferenz (KMK) of several states expanded the exams to scientific subjects and

7104-480: The calculation. Bethe managed to perform the calculation on the train from New York to Schenectady , where he was working for General Electric . He did so by realising that it was a non-relativistic process, which greatly simplified the calculation. The bare energy was easily removed as it was already included in the observed mass of the electron. The self energy term now increased logarithmically instead of linearly, making it mathematically convergent. Bethe arrived at

7215-470: The calculations were still a problem. Using techniques honed from decades of working with nuclear physics, and some experience with calculations involving nuclear explosions, Bethe tackled the problems involved in stellar gravitational collapse , and the way in which various factors affected a supernova explosion. Once again, he was able to reduce the problem to a set of differential equations, and to solve them. At age 85, Bethe wrote an important article about

7326-454: The conference, Strömgren detailed what was known about the temperature, density, and chemical composition of the Sun, and challenged the physicists to come up with an explanation. Gamow and Carl Friedrich von Weizsäcker had proposed in a 1937 paper that the Sun's energy was the result of a proton–proton chain reaction : But this did not account for the observation of elements heavier than helium. By

7437-517: The designation of Professional Engineer (P. Eng.). This designation was unveiled at the CAP congress in 1999 and already more than 200 people carry this distinction. To get the certification, at minimum proof of honours bachelor or higher degree in physics or a closely related discipline must be provided. Also, the physicist must have completed, or be about to complete, three years of recent physics-related work experience after graduation. And, unless exempted,

7548-455: The early 1600s. The work on mechanics , along with a mathematical treatment of physical systems, was further developed by Christiaan Huygens and culminated in Newton's laws of motion and Newton's law of universal gravitation by the end of the 17th century. The experimental discoveries of Faraday and the theory of Maxwell's equations of electromagnetism were developmental high points during

7659-498: The end of the conference, Bethe, working in collaboration with Charles Critchfield , had come up with a series of subsequent nuclear reactions that explained how the Sun shines: That this did not explain the processes in heavier stars was not overlooked. At the time there were doubts about whether the proton–proton cycle described the processes in the Sun, but more recent measurements of the Sun's core temperature and luminosity show that it does. When he returned to Cornell, Bethe studied

7770-459: The first three letters of the Greek alphabet. As one of the Physical Review ' s reviewers, Bethe saw the manuscript and struck out the words "in absentia". Bethe believed that the atomic nucleus was like a quantum liquid drop . He investigated the nuclear matter problem by considering the work conducted by Keith Brueckner on perturbation theory . Working with Jeffrey Goldstone , he produced

7881-646: The head of the new Institute of Physiology at the Goethe University Frankfurt . Bethe attended the Goethe-Gymnasium in Frankfurt , Germany. His education was interrupted in 1916, when he contracted tuberculosis , and he was sent to Bad Kreuznach to recuperate. By 1917, he had recovered sufficiently to attend the local Realschule and the following year, he was sent to the Odenwaldschule ,

7992-498: The hearing. Bethe contended that the developments that led to the successful Teller–Ulam design were a matter of serendipity and not a question of manpower or logical development of previously existing ideas. During the hearing, Bethe and his wife also tried hard to persuade Edward Teller against testifying. However, Teller did not agree, and his testimony played a major role in the revocation of Oppenheimer's security clearance . While Bethe and Teller had been on very good terms during

8103-735: The increasing expectations and requirements for which any profession must take responsibility". Chartered Physicist is considered to be equal in status to Chartered Engineer, which the IoP also awards as a member of the Engineering Council UK, and other chartered statuses in the UK. It is also considered a "regulated profession" under the European professional qualification directives. The Canadian Association of Physicists can appoint an official designation called Professional Physicist ( P. Phys. ), similar to

8214-1172: The largest employer being the last. Physicists in academia or government labs tend to have titles such as Assistants, Professors , Sr./Jr. Scientist, or postdocs . As per the American Institute of Physics , some 20% of new physics Ph.D.s holds jobs in engineering development programs, while 14% turn to computer software and about 11% are in business/education. A majority of physicists employed apply their skills and training to interdisciplinary sectors (e.g. finance ). Job titles for graduate physicists include Agricultural Scientist , Air Traffic Controller , Biophysicist , Computer Programmer , Electrical Engineer , Environmental Analyst , Geophysicist , Medical Physicist , Meteorologist , Oceanographer , Physics Teacher / Professor / Researcher , Research Scientist , Reactor Physicist , Engineering Physicist , Satellite Missions Analyst, Science Writer , Stratigrapher , Software Engineer , Systems Engineer , Microelectronics Engineer , Radar Developer, Technical Consultant, etc. The majority of Physics terminal bachelor's degree holders are employed in

8325-590: The last and second last school year, is the document which contains their grades and formally enables them to attend university . Thus, it encompasses the functions of both a school graduation certificate and a college entrance exam. Abitur confers Allgemeine Hochschulreife (allows students to enter university or Fachhochschule ), while there are other ways of obtaining it. In 2005, some 231,000 students obtained Allgemeine Hochschulreife in Germany. This number rose over time to around 263,000 in 2021. Of those, most obtained their Allgemeine Hochschulreife at

8436-623: The meantime, Bethe worked for Sommerfeld in Munich as a privatdozent . Since Bethe was fluent in English, Sommerfeld had Bethe supervise all his English-speaking postdoctoral fellows, including Lloyd P. Smith from Cornell University . Bethe accepted a request from Karl Scheel to write an article for the Handbuch der Physik on the quantum mechanics of hydrogen and helium. Reviewing the article decades later, Robert Bacher and Victor Weisskopf noted that it

8547-511: The mergers? The 90-year-old Bethe quickly became enthused and soon began the required calculations. The result was a 1998 paper on the "Evolution of Binary Compact Objects Which Merge", which Brown regarded as the best that the two produced together. In 1968, Bethe, along with IBM physicist Richard Garwin , published an article criticising in detail the anti- ICBM defense system proposed by the Department of Defense . The two physicists described in

8658-487: The minimum required. The best possible grade of 1.0 can be achieved if the score ranges between 823 and 900 points; the fraction of students achieving this score is normally only around 0.2%–3% even among the already selective population of Abitur candidates. Around 12%–30% of Abitur candidates achieve grades between 1.0 and 1.9. Historically, very few people received their Abitur in Germany because many attractive jobs did not require one. The number of persons holding

8769-643: The new Nazi government was the Law for the Restoration of the Professional Civil Service . Due to his Jewish background, Bethe was dismissed from his job at the university, which was a government post. Geiger refused to help, but Sommerfeld immediately gave Bethe back his fellowship at Munich. Sommerfeld spent much of the summer term of 1933 finding places for Jewish students and colleagues. Bethe left Germany in 1933, moving to England after receiving an offer for

8880-453: The older literature. Loomis offered Bethe a full professorship at the University of Illinois at Urbana–Champaign, but Cornell matched the position offered, and the salary of $ 6,000. He wrote to his mother: I am about the leading theoretician in America. That does not mean the best. Wigner is certainly better and Oppenheimer and Teller probably just as good. But I do more and talk more and that counts too. On March 17, 1938, Bethe attended

8991-401: The other sciences. Bethe found that he was a poor experimentalist who destroyed his lab coat by spilling sulfuric acid on it, but he found the advanced physics taught by the associate professor, Walter Gerlach , more interesting. Gerlach left in 1925 and was replaced by Karl Meissner , who advised Bethe that he should go to a university with a better school of theoretical physics, specifically

9102-503: The passage of a projectile through a gas. Bethe considered it one of their most influential papers. He also worked on a theory of armor penetration, which was immediately classified by the army, thus making it impossible for Bethe (who was not an American citizen at the time) to access further research on the theory. After receiving security clearance in December 1941, Bethe joined the MIT Radiation Laboratory , where he invented

9213-417: The possibilities of using uranium-235 and plutonium . (Teller then raised the prospect of a thermonuclear device, Teller's "Super" bomb . At one point Teller asked if the nitrogen in the atmosphere could be set alight. It fell to Bethe and Emil Konopinski to perform the calculations demonstrating the virtual impossibility of such an occurrence.) "The fission bomb had to be done," he later recalled, "because

9324-555: The present. Many mathematical and physical ideas used today found their earliest expression in the work of ancient civilizations, such as the Babylonian astronomers and Egyptian engineers , the Greek philosophers of science and mathematicians such as Thales of Miletus , Euclid in Ptolemaic Egypt , Archimedes of Syracuse and Aristarchus of Samos . Roots also emerged in ancient Asian cultures such as India and China, and particularly

9435-689: The prewar years, the conflict between them during the Manhattan Project , and especially during the Oppenheimer episode, permanently marred their relationship. After the war ended, Bethe returned to Cornell. In June 1947, he participated in the Shelter Island Conference . Sponsored by the National Academy of Sciences and held at the Ram's Head Inn on Shelter Island, New York , the conference on

9546-433: The private sector. Other fields are academia, government and military service, nonprofit entities, labs and teaching. Typical duties of physicists with master's and doctoral degrees working in their domain involve research, observation and analysis, data preparation, instrumentation, design and development of industrial or medical equipment, computing and software development, etc. The highest honor awarded to physicists

9657-403: The relative priority of Super research led to Teller's group being removed from T Division and placed directly under Oppenheimer. In September it became part of Fermi's new F Division. Bethe's work at Los Alamos included calculating the critical mass and efficiency of uranium-235 and the multiplication of nuclear fission in an exploding atomic bomb. Along with Richard Feynman , he developed

9768-515: The relevant nuclear reactions and reaction cross sections , leading to his discovery of the carbon-nitrogen-oxygen cycle (CNO cycle) : The two papers, one on the proton–proton cycle, co-authored with Critchfield, and the other on the carbon-oxygen-nitrogen (CNO) cycle, were sent to the Physical Review for publication. After Kristallnacht , Bethe's mother had become afraid to remain in Germany. Taking advantage of her Strasbourg origin, she

9879-460: The school. In some parts of Germany students may prepare a presentation, research paper or participate in a competition, and may take additional oral exams to pass the Abitur if the written exam is poor. Before reunification , Abitur exams were given locally in West Germany , but Bavaria has conducted centralized exams ( Zentralabitur ) since 1854. After reunification, most states of the former East Germany continued centralized exams, and at

9990-675: The second half of his scholarship, Bethe chose to go to Enrico Fermi 's laboratory in Rome in February 1931. He was greatly impressed by Fermi and regretted that he had not gone to Rome first. Bethe developed the Bethe ansatz , a method for finding the exact solutions for the eigenvalues and eigenvectors of certain one-dimensional quantum many-body models. He was influenced by Fermi's simplicity and Sommerfeld's rigor in approaching problems and these qualities influenced his own later research. The Rockefeller Foundation offered an extension of Bethe's fellowship, allowing him to return to Italy in 1932. In

10101-470: The seed, and Teller is the mother, because he remained with the child. As for me, I guess I am the midwife . In 1954, Bethe testified on behalf of J. Robert Oppenheimer during the Oppenheimer security hearing . Specifically, Bethe argued that Oppenheimer's stances against developing the hydrogen bomb in the late 1940s had not hindered its development, a topic which was seen as a key motivating factor behind

10212-462: The social sciences. The physics and chemistry exams include an experiment that must be performed and analyzed. Each semester of a subject studied in the final two years yields up to 15 points for a student, where advanced courses may count double, depending on the state. The final examinations each count quadruple. The exact scoring system depends on the Bundesland in which one takes Abitur. Passing

10323-497: The states of Andhra Pradesh and Telangana this is known as Board of Intermediate Examination (BIE). For professional, specialist programs and well reputed institutions there are entrance tests. For engineering there is a Joint Engineering Entrance Joint Entrance Examination conducted at all India level. For medical undergraduate MBBS programs there is a national eligibility and entrance test known as NEET-UG National Eligibility and Entrance Test conducted at all of India. There

10434-539: The supervision of Ralph Fowler . At the request of Patrick Blackett , who was working with cloud chambers , Bethe created a relativistic version of the Bethe formula. Bethe was known for his sense of humor, and with Guido Beck and Wolfgang Riezler  [ de ] , two other postdoctoral research fellows , created a hoax paper On the Quantum Theory of the Temperature of Absolute Zero where he calculated

10545-938: The term Abitur has roots in the archaic word Abiturium , which in turn was derived from the Latin abiturus (future active participle of abire , thus "someone who is going to leave"). As a matriculation examination , Abitur can be compared to A levels , the Matura or the International Baccalaureate Diploma , which are all ranked as level 4 in the European Qualifications Framework . The Zeugnis der Allgemeinen Hochschulreife ("certificate of general qualification for university entrance"), often referred to as Abiturzeugnis (" Abitur certificate"), issued after candidates have passed their final exams and have had appropriate grades in both

10656-456: The two possible quantum states of hydrogen atoms had slightly more energy than that predicted by the theory of Paul Dirac ; this became known as the Lamb shift . Oppenheimer and Weisskopf suggested that this was a result of quantum fluctuations of the electromagnetic field, which gave the electron more energy. According to pre-war quantum electrodynamics (QED), the energy of the electron consisted of

10767-667: The universities within that state. The academic level of the Abitur is comparable to the International Baccalaureate , the GCE Advanced Level and the Advanced Placement tests . The study requirements for the International Baccalaureate differ little from the German exam requirements. It is the only school-leaving certificate in all states of Germany that allows the graduate (or Abiturient ) to move directly to university . The other school leaving certificates,

10878-453: The use of solar neutrino observations to show that the CNO cycle accounts for approximately 7% of the Sun's energy; the neutrino observations had started with Raymond Davis Jr. , whose experiment was based on Bahcall's calculations and encouragement, and the note led to Davis's receiving a share of the 2002 Nobel Prize. Bethe married Rose Ewald, the daughter of Paul Ewald , on September 13, 1939, in

10989-484: The war ). The Notabitur during World War I included an examination, roughly equivalent to the Abitur exam. The World War II Notabitur , in contrast, was granted without an examination. After the war this was a major disadvantage for the students concerned since, unlike its World War I counterpart, the certificate was generally not recognised in West Germany and never recognised in East Germany . Universities requested

11100-526: The war, Bethe also played an important role in the development of the hydrogen bomb , although he had originally joined the project with the hope of proving it could not be made. Bethe later campaigned with Albert Einstein and the Emergency Committee of Atomic Scientists against nuclear testing and the nuclear arms race . He helped persuade the Kennedy and Nixon administrations to sign, respectively,

11211-407: The years ahead. In 1933, the physics department at Cornell University , New York , was looking for a new theoretical physicist, and Lloyd Smith strongly recommended Bethe. This was supported by Bragg, who was visiting Cornell at the time. In August 1934, Cornell offered Bethe a position as an acting assistant professor. Bethe had already accepted a fellowship for a year to work with Nevill Mott at

11322-511: Was a compliment." After Bethe received his doctorate, Erwin Madelung offered him an assistantship in Frankfurt, and in September 1928 Bethe moved in with his father, who had recently divorced his mother. His father had met Vera Congehl earlier that year and married her in 1929. They had two children, Doris, born in 1933, and Klaus, born in 1934. Bethe did not find the work in Frankfurt very stimulating, and in 1929 he accepted an offer from Ewald at

11433-521: Was able to emigrate to the United States in June 1939 on the French quota, rather than the German one, which was full. Bethe's graduate student Robert Marshak noted that the New York Academy of Sciences was offering a $ 500 prize for the best unpublished paper on the topic of solar and stellar energy. So Bethe, in need of $ 250 to release his mother's furniture, withdrew the CNO cycle paper and sent it in to

11544-738: Was coined by William Whewell (also the originator of the term "scientist") in his 1840 book The Philosophy of the Inductive Sciences . A standard undergraduate physics curriculum consists of classical mechanics , electricity and magnetism , non-relativistic quantum mechanics , optics , statistical mechanics and thermodynamics , and laboratory experience. Physics students also need training in mathematics ( calculus , differential equations , linear algebra , complex analysis , etc.), and in computer science . Any physics-oriented career position requires at least an undergraduate degree in physics or applied physics, while career options widen with

11655-540: Was in Germany. As if I was born in Germany only by mistake, and only came to my true homeland at 28." When the Second World War began, Bethe wanted to contribute to the war effort, but was unable to work on classified projects until he became a citizen. Following the advice of the Caltech aerodynamicist Theodore von Kármán , Bethe collaborated with his friend Edward Teller on a theory of shock waves that are generated by

11766-437: Was not invited to the institute again until after World War II . Bethe arrived in the United States in February 1935, and joined the faculty at Cornell University on a salary of $ 3,000. Bethe's appointment was part of a deliberate effort on the part of the new head of its physics department, Roswell Clifton Gibbs , to move into nuclear physics. Gibbs had hired Stanley Livingston , who had worked with Ernest Lawrence , to build

11877-404: Was professional as well as personal. Peierls aroused Bethe's interest in nuclear physics . After James Chadwick and Maurice Goldhaber discovered the photodisintegration of deuterium , Chadwick challenged Bethe and Peierls to come up with a theoretical explanation of this phenomenon. This they did on the four-hour train ride from Cambridge back to Manchester. Bethe would investigate further in

11988-413: Was required; Bethe demonstrated that this was not necessary. One of Bethe's most famous papers is one he never wrote: the 1948 Alpher–Bethe–Gamow paper . George Gamow added Bethe's name (in absentia) without consulting him, knowing that Bethe would not mind, and against Ralph Alpher 's wishes. This was apparently a reflection of Gamow's sense of humor, wanting to have a paper title that would sound like

12099-400: Was unusual in the depth and breadth of its treatment of the subject that required very little updating for the 1959 edition. Bethe was then asked by Sommerfeld to help him with the handbuch article on electrons in metals. The article covered the basis of what is now called solid state physics . Bethe took a very new field and provided a clear, coherent, and complete coverage of it. His work on

12210-400: Was used in all of Western Germany for a variation of the Abitur until the 1990s; the official term for the German qualification is fachgebundene Hochschulreife . This qualification includes only one foreign language (usually, English). The Abitur , in contrast, usually requires two foreign languages. The Fachabitur also allows the graduate to start studying at a university but is limited to

12321-731: Was very unusual at the time. The equivalent graduation certificate in the Czech Republic , Austria , Poland , Italy and other countries of continental Europe is the Matura ; while in England, Wales , Northern Ireland , Singapore , and the West Indies , it is A-levels ; in Scotland it is Higher Grade ; in the Republic of Ireland it is the Leaving Certificate ; in Greece and Cyprus it

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