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Václav Láska (mathematician)
Václav Jan Láska (1862–1943) was a Czech surveyor, astronomer, geophysicist, and mathematician. He was based mainly at Charles University Charles University (CUNI; , UK; ; ), or historically as the University of Prague (), is the largest university in the Czech Republic. It is one of the List of oldest universities in continuous operation, oldest universities in the world in conti ..., and was the founding director (1920-1933) of the State Institute of Geophysics, which later became the Institute of Geophysics of the Czech Academy of Sciences. Láska's empirical rule This empirical rule is one way how to approximate the distance from an earthquake's epicenter. The rule is most fitting for distance in the range of 2 − 10 Mm (thousand km). ''The epicentral distance in thousands of km is roughly equal to the difference between arrival times of S and P waves in minutes minus 1.'' External links Charles University, Faculty of Mathematics and Physics, Department of Geop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Czech People
The Czechs (, ; singular Czech, masculine: ''Čech'' , singular feminine: ''Češka'' ), or the Czech people (), are a West Slavic ethnic group and a nation native to the Czech Republic in Central Europe, who share a common ancestry, culture, history, and the Czech language. Ethnic Czechs were called Bohemians in English until the early 20th century, referring to the former name of their country, Bohemia, which in turn was adapted from the late Iron Age tribe of Celtic Boii. During the Migration Period, West Slavic tribes settled in the area, "assimilated the remaining Celtic and Germanic populations", and formed a principality in the 9th century, which was initially part of Great Moravia, in form of Duchy of Bohemia and later Kingdom of Bohemia, the predecessors of the modern republic. The Czech diaspora is found in notable numbers in the United States, Germany, Canada, Slovakia, Austria, the United Kingdom, Argentina, Australia, Switzerland, France, Russia, Italy, Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surveyor
Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. These points are usually on the surface of the Earth, and they are often used to establish maps and boundaries for ownership, locations, such as the designated positions of structural components for construction or the surface location of subsurface features, or other purposes required by government or civil law, such as property sales. A professional in land surveying is called a land surveyor. Surveyors work with elements of geodesy, geometry, trigonometry, regression analysis, physics, engineering, metrology, programming languages, and the law. They use equipment, such as total stations, robotic total stations, theodolites, GNSS receivers, retroreflectors, 3D scanners, lidar sensors, radios, inclinometer, handheld tablets, optical and digital levels, subsurface loc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomer
An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galaxies – in either observational astronomy, observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, Sun, solar astronomy, the Star formation, origin or stellar evolution, evolution of stars, or the galaxy formation and evolution, formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole. Types Astronomers typically fall under either of two main types: observational astronomy, observational and theoretical astronomy, theoretical. Observational astronomers make direct observations of Astronomical object, celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate Con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geophysicist
Geophysics () is a subject of natural science concerned with the physical processes and properties of Earth and its surrounding space environment, and the use of quantitative methods for their analysis. Geophysicists conduct investigations across a wide range of scientific disciplines. The term ''geophysics'' classically refers to solid earth applications: Earth's shape; its gravitational, magnetic fields, and electromagnetic fields; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. However, modern geophysics organizations and pure scientists use a broader definition that includes the water cycle including snow and ice; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere and solar-terrestrial physics; and analogous problems associated with the Moon and other planets.Gutenberg, B., 1929, Lehrbuch der Geophysik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematical model, models, and mathematics#Calculus and analysis, change. History One of the earliest known mathematicians was Thales of Miletus (); he has been hailed as the first true mathematician and the first known individual to whom a mathematical discovery has been attributed. He is credited with the first use of deductive reasoning applied to geometry, by deriving four corollaries to Thales's theorem. The number of known mathematicians grew when Pythagoras of Samos () established the Pythagorean school, whose doctrine it was that mathematics ruled the universe and whose motto was "All is number". It was the Pythagoreans who coined the term "mathematics", and with whom the study of mathematics for its own sake begins. The first woman math ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles University
Charles University (CUNI; , UK; ; ), or historically as the University of Prague (), is the largest university in the Czech Republic. It is one of the List of oldest universities in continuous operation, oldest universities in the world in continuous operation, the oldest university north of the Alps and east of University of Paris, Paris. Today, the university consists of 17 faculties located in Prague, Hradec Králové, and Plzeň. History Medieval university (1349–1419) The establishment of a medieval university in Prague was inspired by Holy Roman Emperor Charles IV, Holy Roman Emperor, Charles IV. He requested his friend and ally, Pope Clement VI, to create the university. On 26 January 1347, the pope issued the bull establishing a university in Prague, modeled on the University of Paris, with all four faculty (division), faculties, including theology. On 7 April 1348 Charles, the king of Bohemia, gave to the established university privileges and immunities from the se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Institute Of Geophysics Of The Czech Academy Of Sciences
The Institute of Geophysics, GFÚ (), is a publicly funded scientific research institution in Prague affiliated with the Czech Academy of Sciences (). It focuses on pure and applied research in the Earth sciences, Earth and environmental sciences. History The Institute of Geophysics of the Czech Academy of Sciences is rooted in the (State) Institute of Geophysics established in 1920, also the precursor of two other centres of geophysics, both at the Charles University: the Department of Geophysics in the Faculty of Mathematics and Physics, and Applied Geophysics within the Faculty of Science.Uličný, D., Špičák A., (eds.) (2020) The Czech Academy of Sciences Institute of Geophysics Report 2015–2020. Institute of Geophysics, Czech Academy of Sciences, Prague. 138 p. In the early years of the first Czechoslovak Republic, the Institute of Geophysics was launched by one of the founders of modern seismology, Václav Láska (mathematician), Václav Láska, who served as founding di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-wave
__NOTOC__ In seismology and other areas involving elastic waves, S waves, secondary waves, or shear waves (sometimes called elastic S waves) are a type of elastic wave and are one of the two main types of elastic body waves, so named because they move through the body of an object, unlike surface waves. S waves are transverse waves, meaning that the direction of particle movement of an S wave is perpendicular to the direction of wave propagation, and the main restoring force comes from shear stress. Therefore, S waves cannot propagate in liquids with zero (or very low) viscosity; however, they may propagate in liquids with high viscosity. Similarly, S waves cannot travel through gases. The name ''secondary wave'' comes from the fact that they are the second type of wave to be detected by an earthquake seismograph, after the compressional primary wave, or P wave, because S waves travel more slowly in solids. Unlike P waves, S waves cannot travel through the molten outer cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-wave
A P wave (primary wave or pressure wave) is one of the two main types of elastic body waves, called seismic waves in seismology. P waves travel faster than other seismic waves and hence are the first signal from an earthquake to arrive at any affected location or at a seismograph. P waves may be transmitted through gases, liquids, or solids. Nomenclature The name ''P wave'' can stand for either pressure wave (as it is formed from alternating compressions and rarefactions) or primary wave (as it has high velocity and is therefore the first wave to be recorded by a seismograph). The name '' S wave'' represents another seismic wave propagation mode, standing for secondary or shear wave, a usually more destructive wave than the primary wave. Seismic waves in the Earth Primary and secondary waves are body waves that travel within the Earth. The motion and behavior of both P and S waves in the Earth are monitored to probe the interior structure of the Earth. Discontinuities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1862 Births
Events January * January 1 – The United Kingdom annexes Lagos Island, in modern-day Nigeria. * January 6 – Second French intervention in Mexico, French intervention in Mexico: Second French Empire, French, Spanish and British forces arrive in Veracruz, Mexico. * January 16 – Hartley Colliery disaster in north-east England: 204 men are trapped and die underground when the only shaft becomes blocked. * January 30 – American Civil War: The first U.S. ironclad warship, , is launched in Brooklyn. * January 31 – Alvan Graham Clark makes the first observation of Sirius B, a white dwarf star, through an eighteen-inch telescope at Northwestern University in Illinois. February * February 1 – American Civil War: Julia Ward Howe's "Battle Hymn of the Republic" is published for the first time in the ''Atlantic Monthly''. * February 2 – The Dun Mountain Railway, first railway is opened in New Zealand, by the Dun Mountain Copper Mining Compan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
