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Auger Shower
Air showers are extensive cascades of subatomic particles and ionized nuclei, produced in the atmosphere when a ''primary'' cosmic ray enters the atmosphere. Particles of cosmic radiation can be protons, nuclei, electrons, photons, or (rarely) positrons. Upon entering the atmosphere, they interact with molecules and initiate a particle cascade that lasts for several generations, until the energy of the primary particle is fully converted. If the primary particle is a hadron, mostly light mesons like pions and kaons are produced in the first interactions, which then fuel a hadronic shower component that produces shower particles mostly through pion decay. Primary photons and electrons, on the other hand, produce mainly electromagnetic showers. Depending on the energy of the primary particle, the detectable size of the shower can reach several kilometers in diameter. The air shower phenomenon was unknowingly discovered by Bruno Rossi in 1933 in a laboratory experiment. In 1937 Pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Auger Observatory
The Pierre Auger Observatory is an international cosmic ray observatory in Argentina designed to detect ultra-high-energy cosmic rays: sub-atomic particles traveling nearly at the speed of light and each with energies beyond . In Earth's atmosphere such particles interact with air nuclei and produce various other particles. These effect particles (called an "air shower (physics), air shower") can be detected and measured. But since these high energy particles have an estimated arrival rate of just 1 per km2 per century, the Auger Observatory has created a detection area of —the size of Rhode Island, or Luxembourg—in order to record a large number of these events. It is located in the western Mendoza Province, Argentina, near the Andes. Construction began in 2000, the observatory has been taking production-grade data since 2005 and was officially completed in 2008. The northern site was to be located in southeastern Colorado, United States and hosted by Lamar Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra-high-energy Cosmic Ray
In astroparticle physics, an ultra-high-energy cosmic ray (UHECR) is a cosmic ray with an energy greater than 1 EeV (1018 electronvolts, approximately 0.16 joules), far beyond both the rest mass and energies typical of other cosmic ray particles. The origin of these highest energy cosmic rays is not known. These particles are extremely rare; between 2004 and 2007, the initial runs of the Pierre Auger Observatory (PAO) detected 27 events with estimated arrival energies above , that is, about one such event every four weeks in the area surveyed by the observatory. Observational history The first observation of a cosmic ray particle with an energy exceeding (16 J) was made by John Linsley and Livio Scarsi at the Volcano Ranch experiment in New Mexico in 1962. Cosmic ray particles with even higher energies have since been observed. Among them was the Oh-My-God particle observed by the University of Utah's Fly's Eye experiment on the evening of 15 October 1991 over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Linsley
John David Linsley (12 March 1925 – 15 September 2002) was an American physicist who performed pioneering research on cosmic rays, particularly ultra-high-energy cosmic rays. He did his most significant work from 1959 to 1978 using a ground-based array of detectors at Volcano Ranch in New Mexico. He is best known for being the first to detect an air shower created by a primary particle with an energy of 1020 eV. This was the highest energy cosmic ray observed up to that point. Linsley's observations suggested that not all cosmic rays are confined within the galaxy and showed the first evidence of a flattening of the cosmic ray spectrum at energies above 1018 eV. Early life and career John David Linsley was born on March 12, 1925, in Minneapolis, Minnesota. His father, James Adolphus Linsley, was born in Morris, Minnesota, and worked for the Minneapolis Transit Company as a streetcar conductor. His mother, Martha Carolina Linsley, was born in Follinge, Sweden, and was a grad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano Ranch Experiment
The Volcano Ranch experiment was an array of particle detectors in Volcano Ranch, New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ..., used to measure ultra-high-energy cosmic rays. The array was built by John Linsley and Livio Scarsi in 1959. On February 22, 1962, Linsley observed an air shower at Volcano Ranch created by a primary particle with an energy greater than 1020 eV, the highest energy cosmic ray particle ever detected at the time. Linsley continued to operate Volcano Ranch until 1978, when it was closed due to lack of funding. References * * Cosmic-ray experiments {{particle-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhattan Project
The Manhattan Project was a research and development program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. From 1942 to 1946, the project was directed by Major General Leslie Groves of the United States Army Corps of Engineers, U.S. Army Corps of Engineers. Nuclear physicist J. Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the bombs. The Army program was designated the Manhattan District, as its first headquarters were in Manhattan; the name gradually superseded the official codename, Development of Substitute Materials, for the entire project. The project absorbed its earlier British counterpart, Tube Alloys, and subsumed the program from the American civilian Office of Scientific Research and Development. The Manhattan Project employed nearly 130,000 people at its peak and cost nearly US$2 billion (equivalent to about $ b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lev Landau
Lev Davidovich Landau (; 22 January 1908 – 1 April 1968) was a Soviet physicist who made fundamental contributions to many areas of theoretical physics. He was considered as one of the last scientists who were universally well-versed and made seminal contributions to all branches of physics. He is credited with laying the foundations of twentieth century condensed matter physics, and is also considered arguably the greatest Soviet theoretical physicist. His accomplishments include the independent co-discovery of the density matrix method in quantum mechanics (alongside John von Neumann), the quantum mechanical theory of diamagnetism, the theory of superfluidity, the theory of second-order phase transitions, invention of order parameter technique, the Ginzburg–Landau theory of superconductivity, the theory of Fermi liquids, the explanation of Landau damping in plasma physics, the Landau pole in quantum electrodynamics, the two-component theory of neutrinos, and Landau's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oppenheimer
J. Robert Oppenheimer (born Julius Robert Oppenheimer ; April 22, 1904 – February 18, 1967) was an American theoretical physicist who served as the director of the Manhattan Project's Los Alamos Laboratory during World War II. He is often called the "father of the atomic bomb" for his role in overseeing the development of the first nuclear weapons. Born in New York City, Oppenheimer obtained a degree in chemistry from Harvard University in 1925 and a doctorate in physics from the University of Göttingen in Germany in 1927, studying under Max Born. After research at other institutions, he joined the physics faculty at the University of California, Berkeley, where he was made a full professor in 1936. Oppenheimer made significant contributions to physics in the fields of quantum mechanics and nuclear physics, including the Born–Oppenheimer approximation for molecular wave functions; work on the theory of positrons, quantum electrodynamics, and quantum field theory; and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pic Du Midi De Bigorre
The Pic du Midi de Bigorre () or simply the Pic du Midi (elevation ) is a mountain in the French Pyrenees. It is the site of the Pic du Midi Observatory. Pic du Midi Observatory The Pic du Midi Observatory () is an astronomical observatory located at 2,877 meters on top of the Pic du Midi de Bigorre in the French Pyrenees. It is part of the Observatoire Midi-Pyrénées (OMP) which has additional research stations in the southwestern French towns of Tarbes, Lannemezan, and Auch, as well as many partnerships in South America, Africa, and Asia, due to the guardianship it receives from the French Research Institute for Development (IRD). Construction of the observatory began in 1878 under the auspices of the Société Ramond, but by 1882 the society decided that the spiralling costs were beyond its relatively modest means, and yielded the observatory to the French state, which took it into its possession by a law of 7 August 1882. The 8 metre dome was completed in 1908, u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jungfraujoch
The Jungfraujoch (German language, German: lit. "maiden saddle") is a Saddle (landform), saddle connecting two major Four-thousander, 4000ers of the Bernese Alps: the Jungfrau and the Mönch. It lies at an elevation of above sea level and is directly overlooked by the rocky prominence of the Sphinx Observatory, Sphinx. The Jungfraujoch is a glacier saddle, on the upper snows of the Aletsch Glacier, and part of the Jungfrau-Aletsch protected area, Jungfrau-Aletsch area, situated on the boundary between the cantons of Canton of Bern, Bern and Valais, halfway between Interlaken and Fiesch. Since 1912, the Jungfraujoch has been accessible to tourists by the Jungfrau railway, Jungfrau line, a railway from Interlaken and Kleine Scheidegg, running partly underground through a tunnel through the Eiger and Mönch. The Jungfraujoch railway station, at an elevation of is the List of highest railways in Europe, highest in Europe. It lies east of the saddle, below the Sphinx station, and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heidelberg
Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of students, it is List of cities in Germany by population, Germany's 51st-largest city. Located about south of Frankfurt, Heidelberg is part of the densely populated Rhine-Neckar, Rhine-Neckar Metropolitan Region which has its centre in Mannheim. Heidelberg is located on the Neckar River, at the point where it leaves its narrow valley between the Oden Forest and the Kleiner Odenwald, Little Oden Forest, and enters the wide Upper Rhine Plain. The old town lies in the valley, the end of which is flanked by the Königstuhl (Odenwald), Königstuhl in the south and the Heiligenberg (Heidelberg), Heiligenberg in the north. The majority of the population lives in the districts west of the mountains in the Upper Rhine Plain, into which the city has expan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
