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This article comes from the official account of Wechat: ID:fanpu2019, by Wang Shanqin

Bette is a great master in the field of physics and astrophysics. He has made outstanding contributions to many fields, such as quantum mechanics, solid-state physics, nuclear physics, astrophysics, quantum electrodynamics and particle physics. As a result, he won the Nobel Prize in Physics in 1967 and many other awards. In the Manhattan Project, Bette, as director of the theoretical department, led a group of outstanding physicists to solve many key problems in the manufacturing process of the atomic bomb. Bette is called "the strongest problem solver of the 20th century" by Dyson because of his super computing power, contribution and wide range of learning.

When people talk about the Manhattan Project (Manhattan Project), the first thing most likely to think of is Oppenheimer (J. Robert Oppenheimer,1904-1967), known as the father of the atomic bomb. In fact, Oppenheimer is not involved in the study of atomic bomb principles and specific complex calculations. It is the theoretical department of the Manhattan Project, the most important department in the Los Alamos Laboratory, that undertakes this task.

Hans Albrecht Bethe (1906-2005), director of the theory department, is at the top of this intellectual pyramid. Under his leadership, the theoretical department overcame all kinds of difficulties, solved many important theoretical problems in the process of atomic bomb development, and ensured the success of the project.

Bette. Photo: Los Alamos National Laboratory Bette is also an outstanding master of physics and astrophysics. He was appointed director of the Manhattan Project Theory Department precisely because he was already a leader in the field of nuclear physics in the United States. His scientific research career lasted at least 70 years, including at least 50 years at its peak. During this period, he moved to different fields and achieved important and even epoch-making results, showing extraordinary talent, diligence and creativity. For his systematic and in-depth study of the nuclear fusion process inside the main sequence stars, including the sun, he won the Nobel Prize in physics in 1967 for "his contribution to the theory of nuclear reaction, especially the discovery of energy generation in stars."

This paper introduces Bette's life and scientific contribution.

The proud son of the academic family, Bette was born in Strasbourg, Germany (now France) on July 2, 1906.

Bette's father, Albrecht Bette (Albrecht Julius Theodor Bethe,1872-1954), is a physiologist who studies the nervous system of invertebrates. Albrecht received his Ph. D. from the University of Munich in 1895, worked at the Strasbourg Institute of Physiology from 1896 to 1911, and received his MD there in 1898.

Bette's grandfather, Abraham Kuhn,1838 Kuhn (Abraham Kuhn,1838-1900), is a professor at the University of Strasbourg. His daughter Anna Kuhn,1876 Kuhn (Anna-1966) married Albrecht and changed her name to Anna Bette-Kuhn (Anna Bethe-Kuhn). His grandfather had passed away when Bette was born.

In 1911, Albrecht became professor and director of the Institute of Science at Kiel University. In 1915, Albrecht became director of the Institute of Science at the University of Frankfurt [2]. These two appointments made the Bette family move twice, and Bette went to many schools as a result.

Bette took a picture with her parents at the age of 12. Photo Source: public copyright 1924, graduated from Bette High School and entered the University of Frankfurt to study for a degree in chemistry. It turns out that Bette is not suitable for this major because of his poor experimental ability and repeated problems; at its worst, he spilled sulfuric acid on his lab coat. On this point, he and his later good friend Oppenheimer felt sorry for each other.

In April 1926, on the advice of his teacher, Bette transferred to the University of Munich to study under the famous theoretical physicist Sommerfeld (Arnold Sommerfeld,1868-1951). Bette, who is good at theoretical research, has been like a fish in water ever since. Sommerfeld suggested that Bette study electron diffraction in crystals, which led him to enter the field of solid-state physics.

Bette received his doctorate in 1928 at the age of 22 and joined the Technical University of Stuttgart the following year.

In 1929, Bette published several papers on topics such as the symmetry of the electron energy of hydrogen atoms, the electron distribution of helium gas, and crystal separation, which involved quantum mechanics and solid-state physics. On Sommerfeld's recommendation, Bette received a travel scholarship (Travelling Scholarship) from the Rockefeller Foundation (Rockefeller Foundation) for $150 a month (equivalent to about $2765 in 2023).

In 1930, Bette published a 76-page paper, "the Theory of High-Speed particles passing through matter" [3]. This paper starts from the Schrodinger equation and uses Fourier transform to obtain the famous "Bette Formula" (Bethe formula). This formula describes the average energy loss of particles passing through the medium. Bette later thought it was the greatest paper of his life (without "one"), when he was 24 years old. This paper has been cited more than 6,000 times so far.

In the same year, Bette used the travel scholarship to visit the Cavendish Laboratory at the University of Cambridge to become a postdoctoral fellow at Fowler (Ralph Fowler,1889-1944). Brackett (Patrick Blackett,1897-1974) hopes that he can extend the Bette formula to the relativistic case to describe extremely high-speed particles. Bette fulfilled Brackett's wish by writing the extended formula into the paper Relativistic Electron deceleration Formula [4], which was published in 1932.

While at Cambridge, Bette also worked with young people in the same laboratory to fabricate a prank "paper" written to the editorial department. This "paper" calculates the fine structure constant at absolute zero in degrees Celsius to ridicule some physicists at the time for piecing together physical constants. The master of astrophysics, Arthur Eddington,1882-1944, once used some numbers to piece together the values of fine structure constants. (editor's note: see "he is a master of astrophysics and a stumbling block to the development of the discipline?" ") Bette and others apologized later. [6]

According to the plan, Bette uses the remaining half of the scholarship to visit Fermi's physics laboratory at the University of Rome (Enrico Fermi,1901-1954). Fermi's intelligence convinced Bette and made him feel that it was too late to meet him. On the other hand, Bette is also considered to be the most outstanding person who visited Fermi Lab. Bette inherited the strict style from Sommerfeld and the succinct style from Fermi.

In March 1931, Bette published his early masterpiece, the Theory of Metals. i. Eigenvalues and eigenfunctions of linear atomic chains "[7]. In this paper, the famous "Bette hypothesis" (Bethe ansatz) is proposed to accurately calculate the problem of one-dimensional quantum multibody model and to find the exact eigenvalues and eigenfunctions of the wave functions of some quantum multibody models. So far, this paper has been cited more than 4700 times. One of the To learn topics that the master of physics (Richard Feynman,1918-1988) wrote on the blackboard before his death is the Bette hypothesis problem (Bethe ansatz problems). When Bette published this paper, he was not yet 25 years old.

During his visit to Rome, Bette also worked with Fermi to study quantum electrodynamics (QED). QED is a branch of physics that describes the interaction between electrons / positrons (matter) and photons (radiation). Bette and Fermi collaborated on a QED paper, "the interaction of two electrons", which was published in 1932.

Bette also wrote two reviews in 1932. The first article is about the quantum mechanics of hydrogen and helium, and the second is about electrons in metals. In 1959, Butcher (Robert Bacher,1905-2004) and Weskopf (Victor Weisskopf,1908-2002) read carefully in order to republish Bette's review of quantum mechanics and found that it was so extensive and profound that it could be republished with few updates.

After studying the Beit-Heitler formula, Bette returned to Germany and became an assistant professor at the University of Tubingen in 1932. However, Nazi Germany soon began to reject Semitism. Bette was also implicated and fired from the university because his mother was of Jewish ancestry. With the help of British physicist William Lawrence Bragg,1890 Jr. (William Lawrence Bragg,1890-1971), Bette was offered an one-year lecturer position at the University of Manchester in 1933 and moved quickly to the UK.

During his stay in Britain, Bette befriended fellow German Rudolf Peierls,1907-1995, who also fled Germany because of his Jewish origin. Under its influence, Bette began to study nuclear physics. Perls later became head of Britain's atomic bomb program (the "alloy tube program") and met Bette again at the end of World War II to cooperate on the manufacture of atomic bombs.

Because of his excellent academic ability, Bette was soon hired by Bristol University and Cornell University. Cornell University allowed Bette to enter the job after fulfilling his contract with the University of Bristol.

In 1981, Bette and Hetler (Walter Heinrich Heitler,1904-1934) published the paper on the stopping of fast particles and the production of positrons [9], which studied the scattering of photons by atoms and molecules and the annihilation of photons into electron and positron pairs. This paper puts forward the famous "Bette-Heitler formula". This classic article has been cited over 2500 times.

In February 1935, Bette joined Cornell University. Here he did great research and became friends with Taylor (Edward Teller,1908-2003) and others.

From 1936 to 1937, Bette published three important papers in the field of nuclear physics. The first paper collaborated with Butcher (second author) on the stability of the nucleus [10]; the second one was written by Bette alone on the theory of nuclear dynamics [11]; and the third paper collaborated with Livingston (Milton Livingston,1905-1986, first author) on the experiment of nuclear dynamics [12].

These three papers have a high status in the field of nuclear physics and are called the Bethe's Bible by some scholars at that time.

The high-spirited Bette wrote to her mother and said, "I'm one of the top theorists in America. That doesn't mean I'm the best. Wigner [Eugene Wigner,1902-1995] is certainly better. Oppenheimer and Taylor may be as good as him. But it's also important that I do a lot and talk a lot." [6]

Bette met Ross Ewald (Rose Ewald,1917-2019) while lecturing at Duke University in 1937. She also fled to the United States because of the persecution of Nazi Germany. Rose's father, Paul Ewald (Paul Ewald,1888-1985), was a famous crystallographer and physicist and a pioneer of X-ray diffraction; his doctoral mentor was also Sommerfeld, so he was Bette's brother. Because of this relationship, Ross met Bette in Germany when he was a teenager. After meeting at Duke University, the couple became lovers and married in September 1939.

Bette's wife Ewald (1967). Photo Source: Prometheus of Public copyright Piracy: as early as 1920, Eddington pointed out in his paper that most of the energy of stars comes not from the contraction of stars, but from the fusion of hydrogen nuclei (protons). However, Eddington did not give a specific process of hydrogen fusion into helium.

In 1937, Gamov (George Gamow,1904-1968) and Carl von Weizs ä cker,1912-2007 proposed that protons and protons in the core of the sun were fused into helium through the "proton-proton chain" (pp chain) reaction, releasing energy. In addition, Weizak proposed the carbon-nitrogen-oxygen (CNO) cycle in 1937 and 1938. However, these efforts have not yet given some important specific processes.

The pp chain is based on the reaction of proton fusion to deuterium (D), or pp reaction: two protons are fused into deuterium, releasing a positron and neutrino at the same time. Weizak suggested that Bette study the pp reaction. Almost at the same time, Gamov also asked student Clichfield (Charles Critchfield,1910-1994) to calculate the pp response. The latter completed this calculation in early 1938, and Gamov suggested that this article be sent to Bette for review, because Bette has done a lot of calculations on binuclear reactions [13]. Bette confirmed that Cretchfield's calculations were correct. The two therefore collaborated on the paper "Proton combination to form deuterium". [14]

Bette and Cretchfield calculated as follows: two protons bind to deuterium, deuterium and protons combine to helium-3, helium-3 and helium-4 combine beryllium-7, beryllium-7 decays to lithium-7, lithium-7 binds to protons to form two helium-4.

Later studies have shown that there are four types of pp chains. Bette and Cretchfield calculated what is now known as the II pp chain. The core temperature of the sun is 15.7 million K, and its core hydrogen fusion takes the type I pp chain as the main mode, which contributes 81.6% of the energy to the sun; the II type pp chain contributes 16% of the energy to the sun. Although they do not consider other types of pp chains, their calculation of II-type pp chains is important and excellent enough.

What bothers the two is that if the core temperature of the sun is 40 million K as estimated by Eddington, the brightness of the sun will be much brighter than that observed.

On March 17, 1938, Bette was invited to attend the fourth Washington Annual Conference on theoretical Physics held by Gamov and Taylor. The theme of this annual meeting is "the generation of stellar energy". Bette didn't want to accept the invitation because he was still interested in QED at the time. However, under Taylor's persuasion, he attended the meeting. [13]

At this meeting, Bengt Str ö mgren,1908-1987 announced that, based on his analysis and calculation of the chemical composition of the sun, the temperature of the sun's core is about 15 million K instead of 40 million K. After substituting 15 million K into the calculation of Bette and Cretchfield, the solar brightness obtained is in good agreement with the observed brightness. This is an inspiration to Bette and others.

After the meeting, Bette thought about the nuclear reaction inside a more massive star. The greater the mass of the star, the higher the core temperature and the higher the internal energy production rate. Bette knows that lithium, beryllium and boron are too rare in elements heavier than helium-4, so he thinks carbon is a possible starting point for the reaction. [13]

After two weeks of thinking and calculation [13], Bette rediscovered the CNO cycle. Bette found that the cycle process is carbon-12 → nitrogen-13 → carbon-13 → nitrogen-14 → oxygen-15 → nitrogen-15 → carbon-12. In the whole process, carbon, nitrogen and oxygen act as catalysts and do not consume themselves.

Type I CNO cycle process. H, He, C, N, O, v and γ are hydrogen, helium, carbon, nitrogen, oxygen, neutrino and gamma photon, respectively. Image source: Borb since then, experimental physicists bombarded carbon-12 targets with high-speed protons and quickly found evidence of nitrogen-13 decay. This proves that Bette's calculation is correct. Later studies have shown that there are multiple channels through which hydrogen in stars can be fused into helium through the CNO cycle. What Weizak and Bette discovered is a type I CNO cycle, so it is also called the "Bethe-Weizs ä cker cycle cycle".

Bette wrote the research results into the paper "stellar Energy Generation" [15]. In this paper, Bette further carefully calculated the reaction rate of the pp chain and pointed out that for stars with smaller masses such as the sun, the internal energy mainly comes from the pp chain reaction, while the internal energy of massive stars mainly comes from the CNO cycle. This conclusion is still correct today.

Bette's paper gives the relationship between the energy production rate of the two production modes and the temperature (in units of 1 million K). The dotted line is the pp chain, the dashed line is the CNO loop, and the solid line represents the sum of the two. When the core temperature of the star is lower than 15 million K, the pp chain contributes most of the energy; on the contrary, the CNO cycle contributes most of the energy. Image source: reference [15] Bette put "stellar energy generation" into the Physics Review (Physical Review). Soon after, Bette's doctoral student Marshak (Robert Marshak,1916-1992) noticed that the New York Academy of Sciences was offering a reward of $500 ($10915 in 2023) for the best papers on solar and stellar energy, provided it had not yet been published. [13]

Marshak immediately told Bette the news. Bette quickly withdrew the paper and sent it to the New York Academy of Sciences, winning a prize of $500. He gave Marshak $50 as an information fee. He then sent $250 to the German government to ensure that all items to be moved were properly disposed of when his mother, who was about to flee Germany, moved. [13]

Finally, the landmark paper was re-submitted by Bette to the Physics Review and was published in March 1939. The results of this paper apply not only to the sun, but also to all stars in the main sequence stage (stars in the core hydrogen fusion state). Stars spend most of their lives in the main sequence stage.

After the outbreak of World War II in Europe, the soul of the Manhattan Project, a large number of scholars began to devote themselves to weapons design-related topics. Bette is no exception, working with Taylor to study the shock wave theory of a warhead passing through gas. He also studied the theory of armor penetration, but it was immediately classified by the army, making it impossible for Bette, who had not yet become an American citizen, to dabble any further.

In March 1941, Bette acquired American citizenship, which removed the biggest obstacle for him to engage in military research. In December 1941, Bette finally got security permission to join the radiation laboratory at MIT. There, he invented the "Bette hole directional coupler" (Bethe-hole directional coupler) that can be used in radar groups.

After the Manhattan project was officially launched, Oppenheimer was appointed director of science to co-ordinate all departments. Among these departments, the theory department is responsible for carrying out theoretical calculations and determining the feasibility of various schemes, so it is the most critical department. Oppenheimer wants to be the director of the theory department himself.

However, when Oppenheimer asked his friend Isidor Rabi,1898-1988 for advice on the Manhattan project, the rabbi gave two pieces of advice: don't wear a military uniform; ask Bette to be director of the theory department. Although recalcitrant, Oppenheimer was respectful and obedient to the rabbi, not to mention that he knew that Bette, though still young (35), was already a leader in nuclear physics. As a result, Bette was invited to serve as director of the theoretical department.

The photo of Bette's ID card during the Manhattan Project, whose ID number is K3. Image source: after Los Alamos National Laboratory took office, Bette led members of the theoretical department to calculate the critical mass of uranium 235 (the minimum mass that can be carried out in the chain reaction), efficiency, fission multiplication, hydrodynamics of explosion, neutron initiator, radiative propagation of explosion, and other key issues. Together with Feynman, a member of the theoretical group, he also developed a formula for calculating the equivalent of an atomic bomb. [16]

At a critical moment of intense research and development, Bette played a role in stabilizing the morale: Taylor calculated that a nuclear explosion would cause nitrogen in the earth's atmosphere to accumulate into magnesium and release helium ions, releasing huge energy that would burn up the atmosphere. Bette decided the calculation was wrong the first time. Then he proved his judgment through rigorous calculation and pointed out that Taylor's calculation was based on a wrong hypothesis. Bette's calculations provide enough confidence for Oppenheimer. This is also a passage from Nolan's film Oppenheimer. )

Bette's research in the field of pure science was once greatly reduced as a result of the work of the Manhattan Project. In 1944, he seemed to free up more time and published a paper on electromagnetic wave circular hole diffraction [17], which made a new and in-depth study of the ancient diffraction problems. This article has been quoted more than 3700 times so far.

On July 16, 1945, participants in the Manhattan Project conducted the first nuclear test in human history, the Trinity (Trinity) test, and the world's first atomic bomb exploded successfully. The theory group led by Bette made a vital contribution to its success. All kinds of data measured after the explosion verify the accuracy of the calculation results of the theoretical department.

During the implementation of the Manhattan Project, the Theory Department was the least expensive and most prestigious department of all departments. As the director of the theoretical department, Bette's role is no less than that of Oppenheimer, who co-ordinates the overall situation. The facts also proved that the rabbi's vision: Bette not only has outstanding skills in physics, but also has excellent team leadership. It can be said that Bette is the soul of the Manhattan Project.

Calculation on the train: quantum electrodynamics after World War II, scientists who used to serve wartime military science and technology returned to universities or research institutes. Bette returned to Cornell University to continue his research. At this time, Oppenheimer was no longer doing research, and Bette became the leader of theoretical physics in the United States at that time. Bette also recruited some outstanding young people he met during his participation in the Manhattan Project, such as Feynman, to Cornell University, which became one of the top research centers in theoretical physics in the world at that time.

At this point, the core of the whole theoretical physics is QED. In 1947, Lamb (Willis Lamb,1913-2008) and Robert Retherford,1912-1981 accurately measured in the laboratory that the energy difference between the 2S1/2 and 2P1/2 levels of the hydrogen atom corresponds to a frequency of 1057 MHz, that is, Lamb shift (Lamb shift). However, according to the previous theory, the two energies should be equal. This means that the previous theory must be revised.

In June 1947, the famous Foundations of Quantum Mechanics Island Conference was held at a hotel on New York's Shelter Island with the theme "Quantum Mechanics Foundation". One of the hot topics discussed at this meeting is the mechanism of Lamb shift. Dutch physicist Kramer (Hans Kramers,1894-1952) proposed a "renormalization" (renormalization, renormalization) scheme, but he was unable to make quantitative calculations.

The Shelter Island meeting reignited Bette's interest in QED. Bette believes that the reason for Lamb shift is that the electron releases virtual photons and absorbs them back, a process that produces the "self-energy" of electrons. After the meeting, Bette took a train to Schenectady in eastern New York.

On the train, Bette began to calculate, using a non-relativistic approximation (that is, assuming that electrons move at a low speed, regardless of relativistic effects), and he finished the calculation before the journey was over. The energy level difference calculated by him is 1040 MHz, which is very close to the 1057 MHz measured by the experiment.

Bette quickly wrote the paper and published it in the Physics Review in August 1947. This paper, entitled "electromagnetic level shift" [18], has only 3 pages and contains only 12 mathematical equations, but it has far-reaching implications: it gives a precedent for dealing with infinity and obtaining finite values, and lays a foundation for the development of the new QED theory.

It was during this period that Dyson (Freeman Dyson,1923-2020) came to Cornell University to study as a graduate student with Bette. Bette asked Dyson to repeat his electronic calculations and give a low-order correction. After months of complex calculations, Dyson found that there was no essential difference between the results obtained by Bette and those obtained before. However, after months of training, Dyson, who had no background in physics, became familiar with QED. Since then, Dyson distinguished himself in the field of QED and impressed Oppenheimer, who hired him as a researcher at the Princeton Institute for Advanced Studies in 1952. [19]

After the successful explosion of the hydrogen bomb's "midwife" atomic bomb, Taylor, who had been clamoring to build a hydrogen bomb during the Manhattan Project, asked to continue to study the hydrogen bomb. Due to the strong opposition of Oppenheimer and others, the project has been unable to launch. On August 29, 1949, the Soviet Union successfully detonated an atomic bomb and the nuclear arms race officially began. At the end of January 1950, the then US President Truman decided to start the development of a hydrogen bomb.

The start of the nuclear arms race and the escalation of the Cold War made Bette, who initially opposed the development of a hydrogen bomb, worried about the imbalance between the two sides, so he turned to the development of a hydrogen bomb.

On May 9, 1951, the world's first hydrogen bomb developed by the Taylor team was successfully detonated, which was 10 times as powerful as the Hiroshima atomic bomb. On November 1, 1952, a second hydrogen bomb was detonated, which was 450 times as powerful as the Hiroshima bomb.

Many people call Taylor the father of the hydrogen bomb, while others think that Uram (Stanishamaw Ulam,1909-1984) is the father of the hydrogen bomb. Bette believes that Uram is the father of the hydrogen bomb, Taylor is the mother of the hydrogen bomb, and he himself is a midwife.

Bette said his contribution to the hydrogen bomb project was negligible: "I did very little." I think my main contribution is: I said at a meeting that one inch is 2.54 centimeters, not 2.5 centimeters. [before] the engineers were bound by 2.5, so the centimeter size was always inconsistent with the inch size. So, I solved the problem. " [20]

This statement is obviously self-deprecating, while taking the opportunity to make fun of the daily use of the inch system for scientific and technological research. In fact, according to Dyson's recollection [19], Bette was absent from Cornell for about eight months and his itinerary was kept secret. After the hydrogen bomb successfully exploded, Bette returned to school. Obviously, Bette has done a lot of calculation work in the project team in the past eight months.

After the hydrogen bomb exploded, Taylor intended to continue to build more and stronger hydrogen bombs and engage in a nuclear race with the Soviet Union. On the contrary, Bette hopes that the United States and the Soviet Union can negotiate to achieve nuclear disarmament and avoid the destruction of mankind by the nuclear war. When Oppenheimer was subjected to a security review, Bette persuaded Taylor not to attend to sue Oppenheimer (his persuasion was unsuccessful). At the same time, Bette firmly defended Oppenheimer and represented him at the hearing. Bette said that although Oppenheimer opposes the development of hydrogen bombs, his position does not hinder the progress of hydrogen bomb development.

Revisit: nuclear Physics and Particle Physics from the 1950s to the 1970s, Bette devoted more energy to the study of nuclear physics and particle physics, and conducted in-depth research on many topics such as nuclei, electrons, mesons, particle pairs, Bremsstrahlung and so on.

In 1951, Bette and Edwin Salpeter,1924-2008 jointly published the paper "Relativistic equations of bound States" [21]. In this paper, we study the system of bound states composed of two particles and propose the famous "Beit-Salpied equation" (Bethe-Salpeter equation), whose solution is "Beit-Salpied amplitude" (Bethe-Salpeter amplitude).

Bound state systems are ubiquitous in particle physics, such as mesons composed of quarks and antiquarks, bound states composed of electrons and positrons, bound states composed of electrons and holes, and so on. Bette and Salpied gave a relativistic quantum field theory method to study these bound systems, which is of great significance for physicists to study such systems.

Important papers published by Bette's first author or sole author from 1954 to 1968 include Bremsstrahlung and particle pair production theory. i. Differential cross section [22], "nuclear many-body problem" [23], "reference spectral method of nuclear matter" [24], "three-body correlation of nuclear matter" [25], "Thomas-Fermi theory of nucleons" [26]. These papers have been cited hundreds of times so far, and other papers are too numerous to list. Bette's diligence, high yield and high quality of the paper are amazing.

Supernova research in 1975, 69-year-old Bette retired from Cornell University. Since 2013, Bette has worked with Brown (Gerry Brown,1926-1978) to study the mechanism of "nuclear collapse supernovae", which are formed by massive stars collapsing and exploding.

Before Bette entered the supernova field, scholars in this field thought that the collapse would stop after the star collapsed and the core density was compressed to 0.1 times the nuclear density. Bette soon proved that the collapse would not stop until the core of the star was compressed to a density higher than the density of the nucleus. [13]

Studies by Bette and other scholars have also shown that the internal rebound shock waves are depleted shortly after a nuclear collapse supernova explosion. In 1980, Bette studied the properties of neutrinos emitted by neutron stars. In 1982, Wilson (James Wilson,1922-2007) proposed a "delayed neutrino burst" mechanism: a large number of neutrinos released by the core interact with dense outer matter, transferring a small amount of energy to the matter and blowing up stars. Since then, Bette and Wilson have studied this mechanism in depth, and their paper [27] published in 1985 has become a classic on the subject.

In January 1987, Bette and Brown decided to abandon the study of the mechanism of supernova explosions because there was no observational evidence. However, just a month later, a supernova explosion, called SN 1987A, was observed in the large Magellanic Cloud (LMC). LMC is about 170,000 light-years from Earth, and after the outbreak of SN 1987A, its light traveled through space for about 170,000 years before it reached Earth.

Images of supernova SN 1987A after explosion (left) and before explosion (right). Source: at the bottom of the picture is a nuclear collapse supernova whose neutrinos are detected by two neutrino detectors on Earth, which directly supports the delayed neutrino burst theory. The supernova reignited Bette's enthusiasm for the mechanism of supernova explosions, and he later studied convection and rapid nucleosynthesis during supernova explosions.

In 1990, 84-year-old Bette wrote a long review [28] summarizing the study of nuclear collapse supernova explosions. This review has been an authoritative review in this field for a long time. The elderly Bette continued to write, and his cooperation with Brown on supernovae lasted until 1995.

In the process of studying the mechanism of supernova explosion, Bette often uses 1051 ergs (equal to 1044 joules) as a unit of energy. Later, scholars who study supernovae often call this quantity "1 Bette", or 1B for short. This quantity is also abbreviated to "foe".

Binary merging and gravitational waves in 1996, when Bette and Brown visited the California Institute of Technology, Kip Thorne,1940- sought their help. Thorne was working on the creation of the Laser interference gravitational Wave Observatory (Laser Interferometer Gravitational-Wave Observatory,LIGO). The gravitational waves that can be detected by LIGO mainly come from the processes of merging of double black holes, merging of double neutron stars and merging of black holes and neutron stars.

Thorne wants Bette and Brown to calculate how many gravitational wave events caused by black hole-neutron star merging can be detected by LIGO each year. The two calculated the incidence of neutron star-black hole merging and double neutron star merging events [29] and pointed out that LIGO can find several gravitational waves caused by double compact star coalescence every month, rather than two or three cases a year as previously estimated. [13]

Bette, Brown and Bette's assistants also studied new types of merging of neutron stars and white dwarfs. In addition, he and his collaborators studied black hole systems involving X-ray and gamma-ray bursts and binary star systems with a common envelope (binary stars are so close that the outer material of binary stars is wrapped in binary stars, like peanut shells wrapped in peanuts).

Since 2015, the upgraded LIGO has successively detected the gravitational waves caused by the merging of double black holes and double neutron stars, and is likely to detect the gravitational waves generated by the merging of black holes and neutron stars.

Because Bette's in-depth study of pp chain and CNO cycle has greatly promoted human understanding of stellar energy, the strongest problem solver of the 20th century has been nominated as the Nobel Prize winner in physics since 1943 and won the prize in 1967. He was nominated in 19 of the 25 years from 1943 to 1967. Within months of the news that he had won the prize, his home phone became a hotline, and even strangers of the same surname wrote to him saying they were relatives and asked to share part of the Nobel prize. [13]

In addition to the Nobel Prize in Physics, Bette has also won the Henry Draper Medal (Henry Draper Medal,1947). Editor's note: for Draper, see "he was a doctor but changed astronomy"), Planck Medal (Max Planck Medal,1955), Franklin Medal (Franklin Medal,1959), Eddington Medal (Eddington Medal,1961), Fermi Award (Enrico Fermi Award,1961), Rumford Award (Rumford Prize,1963), National Medal of Science (National Medal of Science,1975), Ozteder Medal (Oersted Medal,1993), Bruce Medal (Bruce Medal) 2001) and other important awards. It seems that the Royal Astronomical Society, which is responsible for awarding the Eddington Medal, did not mind his mischievous article alluding to Eddington and others.

To show respect for Bette and to reward scholars who have made outstanding achievements in the fields of astrophysics, nuclear physics and nuclear astrophysics, the American physical Society has established the Bette Award. The Bette Award has been awarded since 1998.

In 2015, Bette, 97, wrote and published my Astrophysical career (My Life in Astrophysics) at the invitation of the Astronomical and Astrophysical Yearbook (Annual Review of Astronomy & Astrophysics) and with the help of his son Henry George Bethe,1944-2003, summing up his own exploration in astrophysics.

The photo of Bette in my Astrophysical career and the signature below. Photo: Bethe, H. A. My Life in Astrophysics, 2003, ARA&A, 41, 11, Bette died on March 6, 2005 at the age of 98 (not yet 99 years old). His wife died on December 24, 2019 at the age of 102.

In 2012, Harvard University Press published Silvan S. Schweber's biography of Bette, Nuclear Power: the achievements of physicist Hans Bette (Nuclear Forces: The Making of the Physicist Hans Bethe). [6] the main title of the book, "Nuclear Forces", is an ingenious pun, referring both to the "nuclear force" between nuclei (the force that keeps the nucleus from disbanding) and to the power of nuclear weapons. This pun points to Bette's two important identities: a leader in the field of nuclear physics and one of the protagonists in the manufacture of the atomic bomb.

The cover of Bette's biography Nuclear Forces The Making of the Physicist Hans Bethe. Photo Source: Harvard University Press Bette's contribution is of course far beyond atomic bombs and nuclear physics. During his scientific career of more than 70 years, he has made outstanding contributions to many fields such as quantum mechanics, solid-state physics, nuclear physics, astrophysics, quantum electrodynamics and particle physics, and has at least one important achievement every 10 years; at its peak, its important achievements are more intensive.

Bette is one of the few scientists who have been at their peak for a long time and have made great achievements. Dyson says he is by no means overrated as the "strongest problem solver of the 20th century" (supreme problem-solver of the 20th century) [30].

reference

[1] Bethe, Albrecht. The Virtual Laboratory (https://vlp.mpiwg-berlin.mpg.de/people/data?id=per362)

[2] Stahnisch, FW (2016). "From 'Nerve Fiber Regeneration' to' Functional Changes' in the Human Brain-On the Paradigm-Shifting Work of the Experimental Physiologist Albrecht Bethe (1872-1954) in Frankfurt am Main". Front Syst Neurosci. 10: 6. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4766753/)

[3] Bethe, H. Zur Theorie des Durchgangs schneller Korpuskularstrahlen durch Materie, 1930, AnP, 397, 325

[4] Bethe, H. A. Bremsformel f ü r Elektronen relativistischer Geschwindigkeit, 1932, ZPhy, 76,293

[5] Corlin, A., Stein, J. S., Beck, G., & Bethe, H. & Riezler, W. Zuschriften, 1931, NW, 19, 37

Schweber, Silvan S. (2012). Nuclear Forces: The Making of the Physicist Hans Bethe. Cambridge, Massachusetts: Harvard University Press. ISBN 978-0674-06587-1.

[7] Bethe, H. A. Zur Theorie der Metalle. I. Eigenwerte und Eigenfunktionen der linearen Atomkette, ZPhy. 71 (3-4): 205

[8] Bethe, H. A. & Fermi, E. Ü ber die Wechselwirkung von zwei Elektronen, 1932, ZPhy, 77,296

[9] Bethe, H. & Heitler, W. On the Stopping of Fast Particles and on the Creation of Positive Electrons, 1934, RSPSA, 146,83

[10] Bethe, H. A. & Bacher, R. F. Nuclear Radius and Many-Body Problem, 1936, PhRv, 50,977

[11] Bethe, H. A. Nuclear Physics B. Nuclear Dynamics, Theoretical, 1937, RvMP, 9, 69

[12] Livingston, M. S.; Bethe, H. A. Nuclear Physics C. Nuclear Dynamics, Experimental, 1937, RvMP, 9245

[13] Bethe, H. A. My Life in Astrophysics, 2003, ARA&A, 41, 1

[14] Bethe, H. A. & Critchfield, C. L. The Formation of Deuterons by Proton Combination, 1938, PhRv, 54,248

[15] Bethe, H. A. Energy Production in Stars, 1939, PhRv, 55, 434

[16] Hoddeson, Lillian; Henriksen, Paul W.; Meade, Roger A.; Westfall, Catherine L. (1993). Critical Assembly: A Technical History of Los Alamos During the Oppenheimer Years, 1943-1945. New York: Cambridge University Press. ISBN 0521-44132-3. OCLC 26764320.

[17] Bethe, H. A. Theory of Diffraction by Small Holes, 1944, PhRv, 66, 163

[18] Bethe, H. A. The Electromagnetic Shift of Energy Levels, 1947, PhRv, 72, 339

[19] Freeman Dyson, Disturbing the Universe. Harper & Row. 1979. ISBN 978-0-06-011108-3.

[20] Manhattan Project Spotlight: Hans and Rose Bethe (https://ahf.nuclearmuseum.org/manhattan-project-spotlight-hans-and-rose-bethe/)

[21] Salpeter, E. E. & Bethe, H. A., A Relativistic Equation for Bound-State Problems, 1951, PhRv, 84, 1232

[22] Bethe, H. A., & Maximon, L. C. Theory of Bremsstrahlung and Pair Production. I. Differential Cross Section, 1954, PhRv, 93, 768

[23] Bethe, H. A. Nuclear Many-Body Problem, 1956, PhRv, 103, 1353

[24] Bethe, H. A., Brandow, B. H., & Petschek, A. G. Reference Spectrum Method for Nuclear Matter, 1963, PhRv, 129,225

[25] Bethe, H. A. Three-Body Correlations in Nuclear Matter, 1965, PhRv, 138, 804

[26] Bethe, H. A. Thomas-Fermi Theory of Nuclei, 1968, PhRv, 167, 879

[27] Bethe, H. A. & Wilson, J. R. Revival of a stalled supernova shock by neutrino heating, 1985, ApJ, 295,14

[28] Bethe, H. A. Supernova mechanisms, 1990, RvMP, 62, 801

[29] Bethe, H. A. & Brown, G. E. Evolution of Binary Compact Objects That Merge, 1998, ApJ, 506780

[30] Wark, David, The Supreme Problem Solver, Nature, 445, 7124, 149

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