Tsung-Dao Lee is a Chinese-American physicist, known for his work on parity violation, the Lee Model, particle physics, relativistic heavy ion physics, nontopological solitons and soliton stars. He holds the rank of University Professor Emeritus at Columbia University, where he has taught since 1953 and from which he retired in 2012. In 1957, Lee, at the age of 30, won the Nobel Prize in Physics with Franklin C N Yang for their work on the violation of the parity law in weak interactions, which Chien-Shiung Wu experimentally verified in 1956, with her so-called Wu experiment. Lee remains the youngest Nobel laureate in the science fields after World War II, he is the third youngest Nobel laureate in sciences in history after William L. Bragg and Werner Heisenberg. Lee and Yang were the first Chinese laureates. Since he became a naturalized American citizen in 1962, Lee is the youngest American to have won a Nobel Prize. Lee was born in Shanghai, with his ancestral home in nearby Suzhou, his father Chun-kang Lee, one of the first graduates of the University of Nanking, was a chemical industrialist and merchant, involved in China's early development of modern synthesized fertilizer.
Lee's grandfather Chong-tan Lee was the first Chinese Methodist Episcopal senior pastor of St. John's Church in Suzhou. Lee has one sister. Educator Robert C. T. Lee is one of T. D.'s brothers. Lee's mother Chang and brother Robert C. T. moved to Taiwan in the 1950s. They were jailed in Taiwan during the White Terror. Lee received his secondary education in Jiangxi. Due to the Second Sino-Japanese war, Lee's high school education was interrupted, thus he did not obtain his secondary diploma. In 1943, Lee directly applied to and was admitted by the National Che Kiang University. Lee registered as a student in the Department of Chemical Engineering. Lee's talent was discovered and his interest in physics grew rapidly. Several physics professors, including Shu Xingbei and Wang Ganchang guided Lee, he soon transferred into the Department of Physics of National Che Kiang University, where he studied in 1943–1944. However, again disrupted by a further Japanese invasion, Lee continued at the National Southwestern Associated University in Kunming the next year in 1945, where he studied with Professor Wu Ta-You.
Professor Wu nominated Lee for a Chinese government fellowship for graduate study in US. In 1946, Lee went to the University of Chicago and was selected by Professor Enrico Fermi to become his PhD student. Lee received PhD under Fermi in 1950 for his research work Hydrogen Content of White Dwarf Stars. Lee served as research associate and lecturer in physics at the University of California at Berkeley from 1950 to 1951. In 1953, Lee joined Columbia University, his first work at Columbia was on a solvable model of quantum field theory better known as the Lee Model. Soon, his focus turned to the developing puzzle of K meson decays. Lee realized in early 1956. At Lee's suggestion, the first experimental test was on hyperion decay by the Steinberger group. At that time, the experimental result gave only an indication of a 2 standard deviation effect of possible parity violation. Encouraged by this feasibility study, Lee made a systematic study of possible P,T,C and CP violations in weak interactions with collaborators, including C. N. Yang.
After the definitive experimental confirmation by C. S. Wu and her collaborators of parity non-conservation and Yang were awarded the 1957 Nobel Prize for Physics. In the early 1960s, Lee and collaborators initiated the important field of high energy neutrino physics. In 1964, with M. Nauenberg, analyzed the divergences connected with particles of zero rest mass, described a general method known as the KLN theorem for dealing with these divergences, which still plays an important role in contemporary work in QCD, with its massless, self-interacting gluons. In 1974–75, Lee published several papers on "A New Form of Matter in High Density", which led to the modern field of RHIC physics, now dominating the entire high energy nuclear physics field. Besides particle physics, Lee has been active in statistical mechanics, hydrodynamics, many body system, solid state, lattice QCD. In 1983, Lee wrote a paper entitled, "Can Time Be a Discrete Dynamical Variable?". Beginning in 1975, Lee and collaborators established the field of non-topological solitons, which led to his work on soliton stars and black holes throughout the 1980s and 1990s.
From 1997 to 2003 Lee was director of the RIKEN-BNL Research Center, which together with other researchers from Columbia, completed a 1 teraflops supercomputer QCDSP for lattice QCD in 1998 and a 10 teraflops QCDOC machine in 2001. Most Lee and Richard M. Friedberg have developed a new method to solve the Schrödinger Equation, leading to convergent iterative solutions for the long-standing quantum degenerate double-wall potential and other instanton problems, they have done work on the neutrino mapping matrix. Soon after the re-establishment of China-American relations with the PRC, Lee and his wife, Jeanne
Leland Stanford Junior University is a private research university in Stanford, California. Stanford is known for its academic strength, proximity to Silicon Valley, ranking as one of the world's top universities; the university was founded in 1885 by Leland and Jane Stanford in memory of their only child, Leland Stanford Jr. who had died of typhoid fever at age 15 the previous year. Stanford was a U. S. Senator and former Governor of California who made his fortune as a railroad tycoon; the school admitted its first students on October 1, 1891, as a coeducational and non-denominational institution. Stanford University struggled financially after the death of Leland Stanford in 1893 and again after much of the campus was damaged by the 1906 San Francisco earthquake. Following World War II, Provost Frederick Terman supported faculty and graduates' entrepreneurialism to build self-sufficient local industry in what would be known as Silicon Valley; the university is one of the top fundraising institutions in the country, becoming the first school to raise more than a billion dollars in a year.
The university is organized around three traditional schools consisting of 40 academic departments at the undergraduate and graduate level and four professional schools that focus on graduate programs in Law, Medicine and Business. Stanford's undergraduate program is the most selective in the United States by acceptance rate. Students compete in 36 varsity sports, the university is one of two private institutions in the Division I FBS Pac-12 Conference, it has gained the most for a university. Stanford athletes have won 512 individual championships, Stanford has won the NACDA Directors' Cup for 24 consecutive years, beginning in 1994–1995. In addition, Stanford students and alumni have won 270 Olympic medals including 139 gold medals; as of October 2018, 83 Nobel laureates, 27 Turing Award laureates, 8 Fields Medalists have been affiliated with Stanford as students, faculty or staff. In addition, Stanford University is noted for its entrepreneurship and is one of the most successful universities in attracting funding for start-ups.
Stanford alumni have founded a large number of companies, which combined produce more than $2.7 trillion in annual revenue and have created 5.4 million jobs as of 2011 equivalent to the 10th largest economy in the world. Stanford is the alma mater of 30 living billionaires and 17 astronauts, is one of the leading producers of members of the United States Congress. Stanford University was founded in 1885 by Leland and Jane Stanford, dedicated to Leland Stanford Jr, their only child; the institution opened in 1891 on Stanford's previous Palo Alto farm. Despite being impacted by earthquakes in both 1906 and 1989, the campus was rebuilt each time. In 1919, The Hoover Institution on War and Peace was started by Herbert Hoover to preserve artifacts related to World War I; the Stanford Medical Center, completed in 1959, is a teaching hospital with over 800 beds. The SLAC National Accelerator Laboratory, established in 1962, performs research in particle physics. Jane and Leland Stanford modeled their university after the great eastern universities, most Cornell University and Harvard University.
Stanford opened being called the "Cornell of the West" in 1891 due to faculty being former Cornell affiliates including its first president, David Starr Jordan. Both Cornell and Stanford were among the first to have higher education be accessible and open to women as well as to men. Cornell is credited as one of the first American universities to adopt this radical departure from traditional education, Stanford became an early adopter as well. Most of Stanford University is on one of the largest in the United States, it is located on the San Francisco Peninsula, in the northwest part of the Santa Clara Valley 37 miles southeast of San Francisco and 20 miles northwest of San Jose. In 2008, 60% of this land remained undeveloped. Stanford's main campus includes a census-designated place within unincorporated Santa Clara County, although some of the university land is within the city limits of Palo Alto; the campus includes much land in unincorporated San Mateo County, as well as in the city limits of Menlo Park and Portola Valley.
The academic central campus is adjacent to Palo Alto, bounded by El Camino Real, Stanford Avenue, Junipero Serra Boulevard, Sand Hill Road. The United States Postal Service has assigned it two ZIP Codes: 94305 for campus mail and 94309 for P. O. box mail. It lies within area code 650. Stanford operates or intends to operate in various locations outside of its central campus. On the founding grant: Jasper Ridge Biological Preserve is a 1,200-acre natural reserve south of the central campus owned by the university and used by wildlife biologists for research. SLAC National Accelerator Laboratory is a facility west of the central campus operated by the university for the Department of Energy, it contains the longest linear particle accelerator in the world, 2 miles on 426 acres of land. Golf course and a seasonal lake: The university has its own golf course and a seasonal lake, both home to the vulnerable California tiger salamander; as of 2012 Lake Laguni
United States Atomic Energy Commission
The United States Atomic Energy Commission known as the AEC, was an agency of the United States government established after World War II by U. S. Congress to foster and control the peacetime development of atomic science and technology. President Harry S. Truman signed the McMahon/Atomic Energy Act on August 1, 1946, transferring the control of atomic energy from military to civilian hands, effective on January 1, 1947; this shift gave the members of the AEC complete control of the plants, laboratories and personnel assembled during the war to produce the atomic bomb. During its initial establishment and subsequent operationalization, the AEC played a key role in the institutional development of Ecosystem ecology, it provided crucial financial resources, allowing for ecological research to take place. More it enabled ecologists with a wide range of groundbreaking techniques for the completion of their research. In the late 1950s and early 1960s, the AEC approved funding for numerous bioenvironmental projects in the arctic and subarctic regions.
These projects were designed to examine the effects of nuclear energy upon the environment and were a part of the AEC's attempt at creating peaceful applications of atomic energy. An increasing number of critics during the 1960s charged that the AEC's regulations were insufficiently rigorous in several important areas, including radiation protection standards, nuclear reactor safety, plant siting, environmental protection. By 1974, the AEC's regulatory programs had come under such strong attack that the U. S. Congress decided to abolish the AEC; the AEC was abolished by the Energy Reorganization Act of 1974, which assigned its functions to two new agencies: the Energy Research and Development Administration and the Nuclear Regulatory Commission. On August 4, 1977, President Jimmy Carter signed into law The Department of Energy Organization Act of 1977, which created the Department of Energy; the new agency assumed the responsibilities of the Federal Energy Administration, the Energy Research and Development Administration, the Federal Power Commission, various other Federal agencies.
In creating the AEC, Congress declared that atomic energy should be employed not only in the form of nuclear weapons for the nation's defense, but to promote world peace, improve the public welfare and strengthen free competition in private enterprise. At the same time, the McMahon Act which created the AEC gave it unprecedented powers of regulation over the entire field of nuclear science and technology, it furthermore explicitly prevented technology transfer between the United States and other countries, required FBI investigations for all scientists or industrial contractors who wished to have access to any AEC controlled nuclear information. The signing was the culmination of long months of intensive debate among politicians, military planners and atomic scientists over the fate of this new energy source and the means by which it would be regulated. President Truman appointed David Lilienthal as the first Chairman of the AEC. Congress gave the new civilian AEC extraordinary power and considerable independence to carry out its mission.
To provide the AEC exceptional freedom in hiring its scientists and engineers, AEC employees were exempt from the civil service system. The AEC's first order of business was to inspect the scattered empire of atomic plants and laboratories to be inherited from the U. S. Army; because of the need for great security, all production facilities and nuclear reactors would be government-owned, while all technical information and research results would be under AEC control. The National Laboratory system was established from the facilities created under the Manhattan Project. Argonne National Laboratory was one of the first laboratories authorized under this legislation as a contractor-operated facility dedicated to fulfilling the new AEC's missions; the Argonne was the first of the regional laboratories. Others were the Clinton labs and the Brookhaven National Laboratory in the Northeast, although a similar lab in Southern California did not eventuate. On 11 March 1948 Lilienthal and Kenneth Nichols were summoned to the White House where Truman told them "I know you two hate each other’s guts".
He directed that "the primary objective of the AEC was to develop and produce atomic weapons", Nichols was appointed a major general and replaced Leslie Groves as chief of the Armed Forces Special Weapons Project Lilienthal had opposed his appointment. Lilienthal was told to "forgo your desire to place a bottle of milk on every doorstop and get down to the business of producing atomic weapons. Nichols became General Manager of the AEC on 2 November 1953; the AEC was in charge of developing the U. S. nuclear arsenal, taking over these responsibilities from the wartime Manhattan Project. In its first decade, the AEC oversaw the operation of Los Alamos Scientific Laboratory, devoted to weapons development, in 1952, the creation of new second weapons laboratory in California, the Lawrence Livermore National Laboratory; the AEC carried out the "crash program" to develop the hydrogen bomb, the AEC played a key role in the prosecution of the Rosenbergs for espionage. The AEC began a program of regular nuclear weapons testing, both in the faraway Pacific Proving Grounds and at the Nevada Test Site in the western United States.
While the AEC supported much basic research, the vast majority of its early budget was devoted to nuclear weapons development and production. Within the AEC, high-level scientific and technical advice was provided by the General Advisory Committee headed by J. Robert Oppenheimer. In its early years, the General
Karl Ferdinand Braun
Karl Ferdinand Braun was a German inventor and Nobel laureate in physics. Braun contributed to the development of radio and television technology: he shared the 1909 Nobel Prize in Physics with Guglielmo Marconi "for their contributions to the development of wireless telegraphy". Braun was born in Fulda and educated at the University of Marburg and received a Ph. D. from the University of Berlin in 1872. In 1874 he discovered, he became director of the Physical Institute and professor of physics at the University of Strassburg in 1895. In 1897 he built the first cathode-ray cathode ray tube oscilloscope. CRT became the cornerstone in developing electronic television. In early 21st century, the flat screen technologies began to replace the CRT technology on both television sets and computer monitors; the CRT is still called the "Braun tube" in German-speaking countries and other countries such as Korea and Japan. During the development of radio, he worked on wireless telegraphy. In 1897 Braun joined the line of wireless pioneers.
His major contributions were the introduction of a closed tuned circuit in the generating part of the transmitter, its separation from the radiating part by means of inductive coupling, on the usage of crystals for receiving purposes. Around 1898, he invented a crystal detector. Wireless telegraphy claimed Dr. Braun's full attention in 1898, for many years after that he applied himself exclusively to the task of solving its problems. Dr. Braun had written extensively on wireless subjects and was well known through his many contributions to the Electrician and other scientific journals. In 1899, he would apply for the patent Wireless electro transmission of signals over surfaces.. In 1899, he is said to have applied for a patent on Electro telegraphy by means of condensers and induction coils. Pioneers working on wireless devices came to a limit of distance they could cover. Connecting the antenna directly to the spark gap produced only a damped pulse train. There were only a few cycles before oscillations ceased.
Braun's circuit afforded a much longer sustained oscillation because the energy encountered less losses swinging between coil and Leyden Jars. And by means of inductive antenna coupling the radiator was better matched to the generator; the resultant stronger and less bandwidth consuming signals bridged a much longer distance. Braun invented the phased array antenna in 1905, he described in his Nobel Prize lecture how he arranged three antennas to transmit a directional signal. This invention led to the development of radar, smart antennas, MIMO. Braun's British patent on tuning was used by Marconi in many of his tuning patents. Guglielmo Marconi used Braun's patents. Marconi would admit to Braun himself that he had "borrowed" portions of Braun's work. In 1909 Braun shared the Nobel Prize for physics with Marconi for "contributions to the development of wireless telegraphy." The prize awarded to Braun in 1909 depicts this design. Braun experimented at first at the University of Strasbourg. Not before long he bridged a distance of 42 km to the city of Mutzig.
In spring 1899 Braun, accompanied by his colleagues Cantor and Zenneck, went to Cuxhaven to continue their experiments at the North Sea. On 24 September 1900 radio telegraphy signals were exchanged with the island of Heligoland over a distance of 62 km. Light vessels in the river Elbe and a coast station at Cuxhaven commenced a regular radio telegraph service. Braun went to the United States at the beginning of World War I to help defend the German wireless station at Sayville, New York, against attacks by the British-controlled Marconi Corporation. After the US entered the war, Braun was detained, but could move within Brooklyn, New York. Braun died in his house in Brooklyn, before the war ended in 1918. In 1987 the Society for Information Display created the Karl Ferdinand Braun Prize, awarded for an outstanding technical achievement in display technology. U. S. Patent 0,750,429, Wireless Electric Transmission of Signals Over Surfaces U. S. Patent 0,763,345, Means for Tuning and Adjusting Electric Circuits History of radio Invention of radio Edouard Branly Footnotes In the anime adaptation of the 2009 Japanese visual novel, Steins.
Braun', uses the pseudonym'FB', after Karl Ferdinand Braun. GeneralK. F. Braun: "On the current conduction in metal sulphides", Ann. Phys. Chem. 153, 556. An English translation can be found in "Semiconductor Devices: Pioneering Papers", edited by S. M. Sze, World Scientific, Singapore, 1991, pp. 377–380. Keller, Peter A.: The cathode-ray tube: technology and applications. New York: Palisades Press, 1991. ISBN 0-9631559-0-3. Keller, Peter A.: "The 100th Anniversary of the Cathode-Ray Tube," Information Display, Vol. 13, No. 10, 1997, pp. 28–32. F. Kurylo: "Ferdinand Braun Leben und Wirken des Erfinders der Braunschen Röhre Nobelpreis 1909", München: Moos Verlag, 1965. Karl Ferdinand Braun at the Mathematics Genealogy Project "Ferdinand Braun – Biography". Nobel Lectures. Physics 1901-1921, Elsevier Publishing Company, Amsterdam, 1967. Naughton, Russell, "Karl Ferdinand Braun, Dr: 1850 - 1918". "Karl Ferdinand Braun ". Biographies of Famous Electrochemists and Physicists Contributed to Understanding of Electricity.
"Karl Ferdinand Braun, 1850-1918". The Ferdinand-Braun-
New York (state)
New York is a state in the Northeastern United States. New York was one of the original thirteen colonies. With an estimated 19.54 million residents in 2018, it is the fourth most populous state. To distinguish the state from the city with the same name, it is sometimes called New York State; the state's most populous city, New York City, makes up over 40% of the state's population. Two-thirds of the state's population lives in the New York metropolitan area, nearly 40% lives on Long Island; the state and city were both named for the 17th century Duke of York, the future King James II of England. With an estimated population of 8.62 million in 2017, New York City is the most populous city in the United States and the premier gateway for legal immigration to the United States. The New York metropolitan area is one of the most populous in the world. New York City is a global city, home to the United Nations Headquarters and has been described as the cultural and media capital of the world, as well as the world's most economically powerful city.
The next four most populous cities in the state are Buffalo, Rochester and Syracuse, while the state capital is Albany. The 27th largest U. S. state in land area, New York has a diverse geography. The state is bordered by New Jersey and Pennsylvania to the south and Connecticut and Vermont to the east; the state has a maritime border with Rhode Island, east of Long Island, as well as an international border with the Canadian provinces of Quebec to the north and Ontario to the northwest. The southern part of the state is in the Atlantic coastal plain and includes Long Island and several smaller associated islands, as well as New York City and the lower Hudson River Valley; the large Upstate New York region comprises several ranges of the wider Appalachian Mountains, the Adirondack Mountains in the Northeastern lobe of the state. Two major river valleys – the north-south Hudson River Valley and the east-west Mohawk River Valley – bisect these more mountainous regions. Western New York is considered part of the Great Lakes region and borders Lake Ontario, Lake Erie, Niagara Falls.
The central part of the state is dominated by the Finger Lakes, a popular vacation and tourist destination. New York had been inhabited by tribes of Algonquian and Iroquoian-speaking Native Americans for several hundred years by the time the earliest Europeans came to New York. French colonists and Jesuit missionaries arrived southward from Montreal for trade and proselytizing. In 1609, the region was visited by Henry Hudson sailing for the Dutch East India Company; the Dutch built Fort Nassau in 1614 at the confluence of the Hudson and Mohawk rivers, where the present-day capital of Albany developed. The Dutch soon settled New Amsterdam and parts of the Hudson Valley, establishing the multicultural colony of New Netherland, a center of trade and immigration. England seized the colony from the Dutch in 1664. During the American Revolutionary War, a group of colonists of the Province of New York attempted to take control of the British colony and succeeded in establishing independence. In the 19th century, New York's development of access to the interior beginning with the Erie Canal, gave it incomparable advantages over other regions of the U.
S. built its political and cultural ascendancy. Many landmarks in New York are well known, including four of the world's ten most-visited tourist attractions in 2013: Times Square, Central Park, Niagara Falls, Grand Central Terminal. New York is home to the Statue of Liberty, a symbol of the United States and its ideals of freedom and opportunity. In the 21st century, New York has emerged as a global node of creativity and entrepreneurship, social tolerance, environmental sustainability. New York's higher education network comprises 200 colleges and universities, including Columbia University, Cornell University, New York University, the United States Military Academy, the United States Merchant Marine Academy, University of Rochester, Rensselaer Polytechnic Institute, Rockefeller University, which have been ranked among the top 40 in the nation and world; the tribes in what is now New York were predominantly Algonquian. Long Island was divided in half between the Wampanoag and Lenape; the Lenape controlled most of the region surrounding New York Harbor.
North of the Lenape was the Mohicans. Starting north of them, from east to west, were three Iroquoian nations: the Mohawk, the original Iroquois and the Petun. South of them, divided along Appalachia, were the Susquehannock and the Erie. Many of the Wampanoag and Mohican peoples were caught up in King Philip's War, a joint effort of many New England tribes to push Europeans off their land. After the death of their leader, Chief Philip Metacomet, most of those peoples fled inland, splitting into the Abenaki and the Schaghticoke. Many of the Mohicans remained in the region until the 1800s, however, a small group known as the Ouabano migrated southwest into West Virginia at an earlier time, they may have merged with the Shawnee. The Mohawk and Susquehannock were the most militaristic. Trying to corner trade with the Europeans, they targeted other tribes; the Mohawk were known for refusing white settlement on their land and banishing any of their people who converted to Christianity. They posed a major threat to the Abenaki and Mohicans, while the Susquehannock conquered the Lenape in the 1600s.
The most devastating event of the century, was the Beaver Wars. From 1640–1680, Iroquoian peoples waged campaigns which extended from modern-day Michigan to Virginia against Algonquian and Siouan tribes, as well as each other; the ai
A neutrino is a fermion that interacts only via the weak subatomic force and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small that it was long thought to be zero; the mass of the neutrino is much smaller than that of the other known elementary particles. The weak force has a short range, the gravitational interaction is weak, neutrinos, as leptons, do not participate in the strong interaction. Thus, neutrinos pass through normal matter unimpeded and undetected. Weak interactions create neutrinos in one of three leptonic flavors: electron neutrinos, muon neutrinos, or tau neutrinos, in association with the corresponding charged lepton. Although neutrinos were long believed to be massless, it is now known that there are three discrete neutrino masses with different tiny values, but they do not correspond uniquely to the three flavors. A neutrino created with a specific flavor is in an associated specific quantum superposition of all three mass states.
As a result, neutrinos oscillate between different flavors in flight. For example, an electron neutrino produced in a beta decay reaction may interact in a distant detector as a muon or tau neutrino. Although only differences of squares of the three mass values are known as of 2016, cosmological observations imply that the sum of the three masses must be less than one millionth that of the electron. For each neutrino, there exists a corresponding antiparticle, called an antineutrino, which has half-integer spin and no electric charge, they are distinguished from the neutrinos by having opposite signs of lepton chirality. To conserve total lepton number, in nuclear beta decay, electron neutrinos appear together with only positrons or electron-antineutrinos, electron antineutrinos with electrons or electron neutrinos. Neutrinos are created by various radioactive decays, including in beta decay of atomic nuclei or hadrons, nuclear reactions such as those that take place in the core of a star or artificially in nuclear reactors, nuclear bombs or particle accelerators, during a supernova, in the spin-down of a neutron star, or when accelerated particle beams or cosmic rays strike atoms.
The majority of neutrinos in the vicinity of the Earth are from nuclear reactions in the Sun. In the vicinity of the Earth, about 65 billion solar neutrinos per second pass through every square centimeter perpendicular to the direction of the Sun. For study, neutrinos can be created artificially with nuclear reactors and particle accelerators. There is intense research activity involving neutrinos, with goals that include the determination of the three neutrino mass values, the measurement of the degree of CP violation in the leptonic sector. Neutrinos can be used for tomography of the interior of the earth; the neutrino was postulated first by Wolfgang Pauli in 1930 to explain how beta decay could conserve energy and angular momentum. In contrast to Niels Bohr, who proposed a statistical version of the conservation laws to explain the observed continuous energy spectra in beta decay, Pauli hypothesized an undetected particle that he called a "neutron", using the same -on ending employed for naming both the proton and the electron.
He considered that the new particle was emitted from the nucleus together with the electron or beta particle in the process of beta decay. James Chadwick discovered a much more massive neutral nuclear particle in 1932 and named it a neutron leaving two kinds of particles with the same name. Earlier Pauli had used the term "neutron" for both the neutral particle that conserved energy in beta decay, a presumed neutral particle in the nucleus; the word "neutrino" entered the scientific vocabulary through Enrico Fermi, who used it during a conference in Paris in July 1932 and at the Solvay Conference in October 1933, where Pauli employed it. The name was jokingly coined by Edoardo Amaldi during a conversation with Fermi at the Institute of Physics of via Panisperna in Rome, in order to distinguish this light neutral particle from Chadwick's heavy neutron. In Fermi's theory of beta decay, Chadwick's large neutral particle could decay to a proton and the smaller neutral particle: n0 → p+ + e− + νeFermi's paper, written in 1934, unified Pauli's neutrino with Paul Dirac's positron and Werner Heisenberg's neutron–proton model and gave a solid theoretical basis for future experimental work.
The journal Nature rejected Fermi's paper, saying that the theory was "too remote from reality". He submitted the paper to an Italian journal, which accepted it, but the general lack of interest in his theory at that early date caused him to switch to experimental physics. By 1934 there was experimental evidence against Bohr's idea that energy conservation is invalid for beta decay: At the Solvay conference of that year, measurements of the energy spectra of beta particles were reported, showing that there is a strict limit on the energy of electrons from each type of beta decay; such a limit is not expected if the conservation of energy is invalid, in which case any amount of energy would be statistically available in at least a few decays. The natural explanation of the beta decay spectrum as first measured in 1934 was that only a limited amount of en
The Great Depression was a severe worldwide economic depression that took place during the 1930s, beginning in the United States. The timing of the Great Depression varied across nations, it was the longest and most widespread depression of the 20th century. In the 21st century, the Great Depression is used as an example of how intensely the world's economy can decline; the Great Depression started in the United States after a major fall in stock prices that began around September 4, 1929, became worldwide news with the stock market crash of October 29, 1929. Between 1929 and 1932, worldwide gross domestic product fell by an estimated 15%. By comparison, worldwide GDP fell by less than 1% from 2008 to 2009 during the Great Recession; some economies started to recover by the mid-1930s. However, in many countries the negative effects of the Great Depression lasted until the beginning of World War II; the Great Depression had devastating effects in countries both poor. Personal income, tax revenue and prices dropped, while international trade plunged by more than 50%.
Unemployment in the U. S. rose to 25% and in some countries rose as high as 33%. Cities around the world were hit hard those dependent on heavy industry. Construction was halted in many countries. Farming communities and rural areas suffered as crop prices fell by about 60%. Facing plummeting demand with few alternative sources of jobs, areas dependent on primary sector industries such as mining and logging suffered the most. Economic historians attribute the start of the Great Depression to the sudden devastating collapse of U. S. stock market prices on October 29, 1929, known as Black Tuesday. However, some dispute this conclusion and see the stock crash as a symptom, rather than a cause, of the Great Depression. After the Wall Street Crash of 1929 optimism persisted for some time. John D. Rockefeller said "These are days. In the 93 years of my life, depressions have gone. Prosperity has always returned and will again." The stock market turned upward in early 1930. This was still 30% below the peak of September 1929.
Together and business spent more in the first half of 1930 than in the corresponding period of the previous year. On the other hand, many of whom had suffered severe losses in the stock market the previous year, cut back their expenditures by 10%. In addition, beginning in the mid-1930s, a severe drought ravaged the agricultural heartland of the U. S. By mid-1930, interest rates had dropped to low levels, but expected deflation and the continuing reluctance of people to borrow meant that consumer spending and investment were depressed. By May 1930, automobile sales had declined to below the levels of 1928. Prices in general began to decline, although wages held steady in 1930. A deflationary spiral started in 1931. Farmers faced a worse outlook. At its peak, the Great Depression saw nearly 10% of all Great Plains farms change hands despite federal assistance; the decline in the U. S. economy was the factor. Frantic attempts to shore up the economies of individual nations through protectionist policies, such as the 1930 U.
S. Smoot–Hawley Tariff Act and retaliatory tariffs in other countries, exacerbated the collapse in global trade. By 1933, the economic decline had pushed world trade to one-third of its level just four years earlier. Change in economic indicators 1929–32 The two classical competing theories of the Great Depression are the Keynesian and the monetarist explanation. There are various heterodox theories that downplay or reject the explanations of the Keynesians and monetarists; the consensus among demand-driven theories is that a large-scale loss of confidence led to a sudden reduction in consumption and investment spending. Once panic and deflation set in, many people believed they could avoid further losses by keeping clear of the markets. Holding money became profitable as prices dropped lower and a given amount of money bought more goods, exacerbating the drop in demand. Monetarists believe that the Great Depression started as an ordinary recession, but the shrinking of the money supply exacerbated the economic situation, causing a recession to descend into the Great Depression.
Economists and economic historians are evenly split as to whether the traditional monetary explanation that monetary forces were the primary cause of the Great Depression is right, or the traditional Keynesian explanation that a fall in autonomous spending investment, is the primary explanation for the onset of the Great Depression. Today the controversy is of lesser importance since there is mainstream support for the debt deflation theory and the expectations hypothesis that building on the monetary explanation of Milton Friedman and Anna Schwartz add non-monetary explanations. There is consensus that the Federal Reserve System should have cut short the process of monetary deflation and banking collapse. If they had done this, the economic downturn would have been much shorter. British economist John Maynard Keynes argued in The General Theory of Employment and Money that lower aggregate expenditures in the economy contributed to a massive decline in income and to employment, well below the average.
In such a situation, the economy reached equilibrium at low levels of economic activity and high unemployment. Keynes' basic idea was simple