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Whip Cracking
Whipcracking is the act of producing a cracking sound through the use of a whip. Used during livestock driving and horse riding, it has also become an art. A rhythmic whipcracking belongs to the traditional culture among various Germanic peoples of Bavaria ('' Goaßlschnalzen''), various Alpine areas (''Aperschnalzen''), Austria, and Hungary (Ostorozás). Today it is a performing art, a part of rodeo show in United States, a competitive sport in Australia and increasingly popular in the United Kingdom, where it crosses boundaries of sport, hobby and performance. Physics The crack a whip makes is produced when a section of the whip moves faster than the speed of sound creating a small sonic boom. The creation of the sonic boom was confirmed in 1958 by analyzing the high-speed shadow photography taken in 1927.American Physical Society (2002) Whip Cracking Mystery Explained'' 26 May 2002 Recently, an additional, purely geometrical factor was recognized: the tip of the whip moves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonic Boom
A sonic boom is a sound associated with shock waves created when an object travels through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding similar to an explosion or a thunderclap to the human ear. A decibel is the primary unit measurement of sound. "A thunderclap is incredibly loud, producing levels between 100 and 120 dBA (Decibel, decibels A)- the equivalent of standing near a jet during take-off." The crack of a supersonic bullet passing overhead or the crack of a bullwhip are examples of a sonic boom in miniature. Sonic booms due to large supersonic aircraft can be particularly loud and startling, tend to awaken people, and may cause minor damage to some structures. This led to prohibition of routine supersonic flight overland. Although they cannot be completely prevented, research suggests that with careful shaping of the vehicle, the nuisance due to the sonic booms may be reduced to the point that overland super ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discover (magazine)
''Discover'' is an American general audience science magazine launched in October 1980 by Time Inc. It has been owned by Kalmbach Publishing since 2010. History Founding ''Discover'' was created primarily through the efforts of ''Time'' magazine editor Leon Jaroff. He noticed that magazine sales jumped every time the cover featured a science topic. Jaroff interpreted this as a considerable public interest in science, and in 1971, he began agitating for the creation of a science-oriented magazine. This was difficult, as a former colleague noted, because "Selling science to people who graduated to be managers was very difficult".Hevesi, Dennis"Leon Jaroff, Editor at Time and Discover Magazines, Dies at 85" ''The New York Times'', 21 October 2012 Jaroff's persistence finally paid off, and ''Discover'' magazine published its first edition in 1980. ''Discover'' was originally launched into a burgeoning market for science magazines aimed at educated non-professionals, intended to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannon
A cannon is a large- caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during the late 19th century. Cannons vary in gauge, effective range, mobility, rate of fire, angle of fire and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield. A cannon is a type of heavy artillery weapon. The word ''cannon'' is derived from several languages, in which the original definition can usually be translated as ''tube'', ''cane'', or ''reed''. In the modern era, the term ''cannon'' has fallen into decline, replaced by ''guns'' or ''artillery'', if not a more specific term such as howitzer or mortar, except for high-caliber automatic weapons firing bigger rounds than machine guns, called autocannons. The earliest known depict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apatosaurus
''Apatosaurus'' (; meaning "deceptive lizard") is a genus of herbivorous sauropod dinosaur that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, ''A. ajax'', in 1877, and a second species, ''A. louisae'', was discovered and named by William H. Holland in 1916. ''Apatosaurus'' lived about 152 to 151 million years ago (mya), during the late Kimmeridgian to early Tithonian age, and are now known from fossils in the Morrison Formation of modern-day Colorado, Oklahoma, New Mexico, Wyoming, and Utah in the United States. ''Apatosaurus'' had an average length of , and an average mass of . A few specimens indicate a maximum length of 11–30% greater than average and a mass of approximately . The cervical vertebrae of ''Apatosaurus'' are less elongated and more heavily constructed than those of ''Diplodocus'', a diplodocid like ''Apatosaurus'', and the bones of the leg are much stockier despite being longer, imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Simulation
Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be determined by comparing their results to the real-world outcomes they aim to predict. Computer simulations have become a useful tool for the mathematical modeling of many natural systems in physics (computational physics), astrophysics, climatology, chemistry, biology and manufacturing, as well as human systems in economics, psychology, social science, health care and engineering. Simulation of a system is represented as the running of the system's model. It can be used to explore and gain new insights into new technology and to estimate the performance of systems too complex for analytical solutions. Computer simulations are realized by running computer programs that can be either small, running almost instantly on small devices, or large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft
Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washington, United States. Its best-known software products are the Windows line of operating systems, the Microsoft Office suite, and the Internet Explorer and Edge web browsers. Its flagship hardware products are the Xbox video game consoles and the Microsoft Surface lineup of touchscreen personal computers. Microsoft ranked No. 21 in the 2020 Fortune 500 rankings of the largest United States corporations by total revenue; it was the world's largest software maker by revenue as of 2019. It is one of the Big Five American information technology companies, alongside Alphabet, Amazon, Apple, and Meta. Microsoft was founded by Bill Gates and Paul Allen on April 4, 1975, to develop and sell BASIC interpreters for the Altair 8800. It rose to do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nathan Myhrvold
Nathan Paul Myhrvold (born August 3, 1959), formerly Chief Technology Officer at Microsoft, is co-founder of Intellectual Ventures and the principal author of ''Modernist Cuisine'' and its successor books. Myhrvold was listed as co-inventor on 17 U.S. patents at Microsoft and is co-inventor on over 900 other U.S. patents issued to his corporation and its affiliates. Early life and education Myhrvold was born on August 3, 1959 in Seattle, Washington to Norwegian American parents. He was raised in Santa Monica, California, where he attended Mirman School and Santa Monica High School, graduating in 1974, and began college at age 14. Transferring from Santa Monica College, he studied mathematics (B.Sc.), and geophysics and space physics (Master's) at UCLA. He was awarded a Hertz Foundation Fellowship for graduate study and studied at Princeton University, where he earned a master's degree in mathematical economics and completed a Ph.D. in applied mathematics after completing a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya; their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomic, morphological and ecological standpoints. Birds, at over 10,700 living species, are among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontologist
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossils to classify organisms and study their interactions with each other and their environments (their paleoecology). Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek (, "old, ancient"), (, ( gen. ), "being, creature"), and (, "speech, thought, study"). Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of anatomically modern humans. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics, and engineering. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Scientist
A computer scientist is a person who is trained in the academic study of computer science. Computer scientists typically work on the theoretical side of computation, as opposed to the hardware side on which computer engineers mainly focus (although there is overlap). Although computer scientists can also focus their work and research on specific areas (such as algorithm and data structure development and design, software engineering, information theory, database theory, computational complexity theory, numerical analysis, programming language theory, computer graphics, and computer vision), their foundation is the theoretical study of computing from which these other fields derive. A primary goal of computer scientists is to develop or validate models, often mathematical, to describe the properties of computational systems (processors, programs, computers interacting with people, computers interacting with other computers, etc.) with an overall objective of discovering des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discover Magazine
''Discover'' is an American general audience science magazine launched in October 1980 by Time Inc. It has been owned by Kalmbach Publishing since 2010. History Founding ''Discover'' was created primarily through the efforts of ''Time'' magazine editor Leon Jaroff. He noticed that magazine sales jumped every time the cover featured a science topic. Jaroff interpreted this as a considerable public interest in science, and in 1971, he began agitating for the creation of a science-oriented magazine. This was difficult, as a former colleague noted, because "Selling science to people who graduated to be managers was very difficult".Hevesi, Dennis"Leon Jaroff, Editor at Time and Discover Magazines, Dies at 85" ''The New York Times'', 21 October 2012 Jaroff's persistence finally paid off, and ''Discover'' magazine published its first edition in 1980. ''Discover'' was originally launched into a burgeoning market for science magazines aimed at educated non-professionals, intended to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
