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Vincent Courtillot
Vincent E. Courtillot (born 6 March 1948) is an emeritus French geophysicist, prominent among the researchers who are critical of the hypothesis that impact events are a primary cause of mass extinction of life forms on the Earth. He is known for his book ''La Vie en catastrophes'' (Paris, Fayard, 1995), translated into English as ''Evolutionary catastrophes'' (1999). Biography Courtillot is an engineer from the École nationale supérieure des Mines de Paris. He then studied at Stanford University. In 1974, he was awarded a doctorate by University Paris 6 and in 1977 a state doctorate by University Paris 7. He has pursued an academic career in France and the United States, including teaching stints at Caltech and the University of Minnesota, and work with the Institut de Physique du Globe de Paris (where he has been director since 2004), and the Ministry of National Education in France. (From 1998 to 2001 Courtillot served under Claude Allègre as director of research when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuilly-sur-Seine
Neuilly-sur-Seine (; 'Neuilly-on-Seine'), also known simply as Neuilly, is an urban Communes of France, commune in the Hauts-de-Seine Departments of France, department just west of Paris in France. Immediately adjacent to the city, north of the Bois de Boulogne, the area is composed of mostly select residential neighbourhoods, as well as many corporate headquarters and a handful of foreign embassies. One of the most affluent areas of France, it is the wealthiest and most expensive suburb of Paris. Together with the 16th arrondissement of Paris, 16th and 7th arrondissement of Paris, the town of Neuilly-sur-Seine forms the most affluent residential area in France. , it is the commune with the fourth highest median per capita income (€52,570 per year) in France. History Originally, Pont de Neuilly was a small hamlet under the jurisdiction of Villiers, a larger settlement mentioned in medieval sources as early as 832 and now absorbed by the commune of Levallois-Perret. It was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Minnesota
The University of Minnesota Twin Cities (historically known as University of Minnesota) is a public university, public Land-grant university, land-grant research university in the Minneapolis–Saint Paul, Twin Cities of Minneapolis and Saint Paul, Minnesota, United States. It is the Flagship#Colleges and universities in the United States, flagship institution of the University of Minnesota System and is organized into 19 colleges, schools, and other major academic units. The Twin Cities campus is the oldest and largest in the University of Minnesota system and has the List of United States university campuses by enrollment, ninth-largest (as of the 2022–2023 academic year) main campus student body in the United States, with 54,890 students at the start of the 2023–24 academic year. The campus comprises locations in Minneapolis and Falcon Heights, Minnesota, Falcon Heights, a suburb of St. Paul, approximately apart. The Minnesota Territorial Legislature drafted a charter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luis Walter Alvarez
Luis Walter Alvarez (June 13, 1911 – September 1, 1988) was an American experimental physicist, inventor, and professor who was awarded the Nobel Prize in Physics in 1968 for his discovery of resonance (particle physics), resonance states in particle physics using the Bubble chamber, hydrogen bubble chamber. In 2007 the ''American Journal of Physics'' commented, "Luis Alvarez was one of the most brilliant and productive experimental physicists of the twentieth century." After receiving his PhD from the University of Chicago in 1936, Alvarez went to work for Ernest Lawrence at the Lawrence Berkeley National Lab, Radiation Laboratory at the University of California, Berkeley. Alvarez devised a set of experiments to observe K-electron capture in radioactivity, radioactive nuclei, predicted by the beta decay theory but never before observed. He produced tritium using the cyclotron and measured its lifetime. In collaboration with Felix Bloch, he measured the Neutron magnetic momen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism
Volcanism, vulcanism, volcanicity, or volcanic activity is the phenomenon where solids, liquids, gases, and their mixtures erupt to the surface of a solid-surface astronomical body such as a planet or a moon. It is caused by the presence of a heat source, usually internally generated, inside the body; the heat is generated by various processes, such as radioactive decay or tidal heating. This heat partially melts solid material in the body or turns material into gas. The mobilized material rises through the body's interior and may break through the solid surface. Causes For volcanism to occur, the temperature of the mantle must have risen to about half its melting point. At this point, the mantle's viscosity will have dropped to about 1021 Pascal-seconds. When large scale melting occurs, the viscosity rapidly falls to 103 Pascal-seconds or even less, increasing the heat transport rate a million-fold. The occurrence of volcanism is partially due to the fact that melted materi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesozoic Era
The Mesozoic Era is the era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of archosaurian reptiles such as the dinosaurs, and of gymnosperms such as cycads, ginkgoaceae and araucarian conifers; a hot greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of the three eras since complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic. The era began in the wake of the Permian–Triassic extinction event, the largest mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction whose victims included the non-avian dinosaurs, pterosaurs, mosasaurs, and plesiosaurs. The Mesozoic was a time of significant tectonic, climatic, and evolutionary activity. The supercontinent Pangaea began to break apart into separate landmasses. The climate of the Mesozoic was varied, alternating bet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous–Paleogene Extinction Event
The Cretaceous–Paleogene (K–Pg) extinction event, also known as the K–T extinction, was the extinction event, mass extinction of three-quarters of the plant and animal species on Earth approximately 66 million years ago. The event caused the extinction of all non-avian dinosaurs. Most other tetrapods weighing more than also became extinct, with the exception of some ectothermic species such as sea turtles and crocodilians. It marked the end of the Cretaceous period, and with it the Mesozoic era, while heralding the beginning of the current era, the Cenozoic. In the geologic record, the K–Pg event is marked by a thin layer of sediment called the Cretaceous–Paleogene boundary, K–Pg boundary or K–T boundary, which can be found throughout the world in marine and terrestrial rocks. The boundary clay shows unusually high levels of the metal iridium, which is more common in asteroids than in the Earth's crust. As originally proposed in 1980 by a team of scientists le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siberian Traps
The Siberian Traps () are a large region of volcanic rock, known as a large igneous province, in Siberia, Russia. The massive eruptive event that formed the trap rock, traps is one of the largest known Volcano, volcanic events in the last years. The eruptions continued for roughly two million years and spanned the Permian–Triassic boundary, or P–T boundary, which occurred around 251.9 million years ago. The Siberian Traps are believed to be the primary cause of the Permian–Triassic extinction event, the most severe extinction event in the geologic record."New Studies of Permian Extinction Shed Light On the Great Dying" New York Times, April 30, 2012. Retrieved on May 2, 2012. Subsequent periods of Siberian Traps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic Era
The Paleozoic ( , , ; or Palaeozoic) Era is the first of three geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma at the start of the Mesozoic Era. The Paleozoic is subdivided into six geologic periods (from oldest to youngest), Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian. Some geological timescales divide the Paleozoic informally into early and late sub-eras: the Early Paleozoic consisting of the Cambrian, Ordovician and Silurian; the Late Paleozoic consisting of the Devonian, Carboniferous and Permian. The name ''Paleozoic'' was first used by Adam Sedgwick (1785–1873) in 1838 to describe the Cambrian and Ordovician periods. It was redefined by John Phillips (1800–1874) in 1840 to cover the Cambrian to Permian periods. It is derived from the Greek ''palaiós'' (παλαιός, "old") and ''zōḗ'' (ζωή, "life") meaning "ancient lif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Extinctions
An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp fall in the diversity and abundance of multicellular organisms. It occurs when the rate of extinction increases with respect to the background extinction rate and the rate of speciation. Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty. These differences stem from disagreement as to what constitutes a "major" extinction event, and the data chosen to measure past diversity. The "Big Five" mass extinctions In a landmark paper published in 1982, Jack Sepkoski and David M. Raup identified five particular geological intervals with excessive diversity loss. They were originally identified as outliers on a general trend of decreasing extinction rates during the Phanerozoic, but as more stringent statistical tests have been applie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Academy Of Sciences
The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefront of scientific developments in Europe in the 17th and 18th centuries, and is one of the earliest Academy of Sciences, Academies of Sciences. Currently headed by Patrick Flandrin (President of the academy), it is one of the five Academies of the . __TOC__ History The Academy of Sciences traces its origin to Colbert's plan to create a general academy. He chose a small group of scholars who met on 22 December 1666 in the King's library, near the present-day Bibliothèque nationale de France, Bibliothèque Nationale, and thereafter held twice-weekly working meetings there in the two rooms assigned to the group. The first 30 years of the academy's existence were relatively informal, since no statutes had as yet been laid down for the ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Recherche
''La Recherche'' is a monthly French language popular science magazine covering recent scientific news. It is published by the Société d'éditions scientifiques (the ''Scientific Publishing Group''), a subsidiary of Financière Tallandier. Tallandier is owned by Artémis, an investment company of François-Henri Pinault. The headquarters is in Paris. History Created in 1946 Under the name ''Atomes'' (''Atoms''), it changed its name to the current ''La Recherche'' in 1970. The first issue with the title was published in May 1970. It absorbed the French journal ''Nucleus'', formerly ''La Revue Scientifique de France et de l'étranger'' (the ''Scientific Journal of France and Abroad'') in 1971, followed by ''Science Progrès, Découverte'', formerly ''La Nature'' in 1973. ''La Recherche'' is published monthly. The website of the magazine was started in 1995. References External links *Official website ''This article incorporates text from the French language Wikipedia article' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
