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1942 In Science
The year 1942 in science and technology involved some significant events, listed below. Astronomy * February 27 – James Stanley Hey, a British Army research officer, first detects radio waves emitted by the Sun, helping to pioneer radio astronomy. * October 3 – The first V-2 rocket is successfully launched from Test Stand VII at Peenemünde, Germany, flying a distance of 147 km and reaching a height of 84.5 km, becoming the first man-made object to reach space. Biology * German pathologist Max Westenhöfer first puts forward an aquatic ape hypothesis. Chemistry * Cyanoacrylate adhesive is invented by Harry Coover of Eastman Kodak. * Eastman Kodak first market Kodacolor color negative film. Computer science * John V. Atanasoff with Clifford Berry successfully test the Atanasoff–Berry Computer, the first electronic digital computing device. Mathematics * December – Raphaël Salem and Donald C. Spencer publish a progression-free Salem–Spencer set of the numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science
Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for scientific reasoning is tens of thousands of years old. The earliest written records in the history of science come from Ancient Egypt and Mesopotamia in around 3000 to 1200 BCE. Their contributions to mathematics, astronomy, and medicine entered and shaped Greek natural philosophy of classical antiquity, whereby formal attempts were made to provide explanations of events in the physical world based on natural causes. After the fall of the Western Roman Empire, knowledge of Greek conceptions of the world deteriorated in Western Europe during the early centuries (400 to 1000 CE) of the Middle Ages, but was preserved in the Muslim world during the Islamic Golden Age and later by the efforts of Byzantine Greek scholars who brought Greek ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kodacolor (still Photography)
In still photography, Kodak's Kodacolor brand has been associated with various color negative films (i.e., films that produce negatives for making color prints on paper) since 1942. Kodak claims that Kodacolor was "the world's first true color negative film". More accurately, it was the first color negative film intended for making paper prints: in 1939, Agfa had introduced a 35 mm Agfacolor negative film for use by the German motion picture industry, in which the negative was used only for making positive projection prints on 35 mm film. There have been several varieties of Kodacolor negative film, including Kodacolor-X, Kodacolor VR and Kodacolor Gold. The name "Kodacolor" was originally used for a very different lenticular color home movie system, introduced in 1928 and retired after Kodachrome film made it obsolete in 1935. Varieties of Kodacolor-branded print film Kodacolor Kodacolor is a color negative film that was manufactured by Eastman Kodak between 1942 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chief Of Engineers
The Chief of Engineers is a principal United States Army staff officer at The Pentagon. The Chief advises the Army on engineering matters, and serves as the Army's topographer and proponent for real estate and other related engineering programs. The Chief of Engineers is the senior service engineer for the Department of Defense, responsible for integrating all aspects of combat, general and geospatial engineering across the Joint Force. The Chief of Engineers also commands the United States Army Corps of Engineers. As commander of the US Army Corps of Engineers, the Chief of Engineers leads a major Army command that is the world's largest public engineering, design and construction management agency. This office defines policy and guidance, and it plans direction for the organizations within the Corps. The Chief of Engineers is currently a lieutenant general billet but in the past has been held by field grade officers as low as major. Civilian oversight of the Chief of Enginee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The National Academy Of Sciences
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salem–Spencer Set
In mathematics, and in particular in arithmetic combinatorics, a Salem-Spencer set is a set of numbers no three of which form an arithmetic progression. Salem–Spencer sets are also called 3-AP-free sequences or progression-free sets. They have also been called non-averaging sets, but this term has also been used to denote a set of integers none of which can be obtained as the average of any subset of the other numbers. Salem-Spencer sets are named after Raphaël Salem and Donald C. Spencer, who showed in 1942 that Salem–Spencer sets can have nearly-linear size. However a later theorem of Klaus Roth shows that the size is always less than linear. Examples For k=1,2,\dots the smallest values of n such that the numbers from 1 to n have a k-element Salem-Spencer set are :1, 2, 4, 5, 9, 11, 13, 14, 20, 24, 26, 30, 32, 36, ... For instance, among the numbers from 1 to 14, the eight numbers : form the unique largest Salem-Spencer set. This example is shifted by adding one to the ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Donald C
Donald is a masculine given name derived from the Gaelic name ''Dòmhnall''.. This comes from the Proto-Celtic *''Dumno-ualos'' ("world-ruler" or "world-wielder"). The final -''d'' in ''Donald'' is partly derived from a misinterpretation of the Gaelic pronunciation by English speakers, and partly associated with the spelling of similar-sounding Germanic names, such as ''Ronald''. A short form of ''Donald'' is ''Don''. Pet forms of ''Donald'' include ''Donnie'' and ''Donny''. The feminine given name ''Donella'' is derived from ''Donald''. ''Donald'' has cognates in other Celtic languages: Modern Irish ''Dónal'' (anglicised as ''Donal'' and ''Donall'');. Scottish Gaelic ''Dòmhnall'', ''Domhnull'' and ''Dòmhnull''; Welsh '' Dyfnwal'' and Cumbric ''Dumnagual''. Although the feminine given name ''Donna'' is sometimes used as a feminine form of ''Donald'', the names are not etymologically related. Variations Kings and noblemen Domnall or Domhnall is the name of many ancie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raphaël Salem
Raphaël Salem (Greek: Ραφαέλ Σαλέμ; November 7, 1898 in Salonika, Ottoman Empire (now Thessaloniki, Greece) – June 20, 1963 in Paris, France) was a Greek mathematician after whom are named the Salem numbers and Salem–Spencer sets and whose widow founded the Salem Prize. Biography Raphaël Salem was born in Saloniki to Emmanuel and Fortunée Salem. His father was a well known lawyer who dealt with international problems. Raphaël was brought up in a Jewish family who followed the traditions of their ancestors. At age 15 the family moved to France and Salem attended the Lycée Condorcet for two years. Believing that he would follow in father's footsteps, Salem entered the Law Faculty of the University of Paris. His interests, though, were not in law but rather in mathematics and engineering. Soon there after Salem started taking mathematics courses with Hadamard all the while continuing his studies for law. In 1919 he received his law degree. He then began working ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, engineering, mathematical, technological and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology and software engineering. The term "computing" is also synonymous with counting and calculating. In earlier times, it was used in reference to the action performed by mechanical computing machines, and before that, to human computers. History The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. Computing is intimately tied to the representation of numbers, though mathematical conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Data
Digital data, in information theory and information systems, is information represented as a string of discrete symbols each of which can take on one of only a finite number of values from some alphabet, such as letters or digits. An example is a text document, which consists of a string of alphanumeric characters . The most common form of digital data in modern information systems is ''binary data'', which is represented by a string of binary digits (bits) each of which can have one of two values, either 0 or 1. Digital data can be contrasted with ''analog data'', which is represented by a value from a continuous range of real numbers. Analog data is transmitted by an analog signal, which not only takes on continuous values, but can vary continuously with time, a continuous real-valued function of time. An example is the air pressure variation in a sound wave. The word ''digital'' comes from the same source as the words digit and ''digitus'' (the Latin word for ''finger'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronics
The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification and rectification, which distinguishes it from classical electrical engineering, which only uses passive effects such as resistance, capacitance and inductance to control electric current flow. Electronics has hugely influenced the development of modern society. The central driving force behind the entire electronics industry is the semiconductor industry sector, which has annual sales of over $481 billion as of 2018. The largest industry sector is e-commerce, which generated over $29 trillion in 2017. History and development Electronics has hugely influenced the development of modern society. The identification of the electron in 1897, along with the subsequent invention of the vacuum tube which could amplify and rectify small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
