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Henry Margenau
Henry Margenau (April 30, 1901 – February 8, 1997) was a German-American physicist, and philosopher of science. Biography Early life Born in Bielefeld, Germany, Margenau obtained his bachelor's degree from Midland Lutheran College, Nebraska before his M.Sc. from the University of Nebraska in 1926, and PhD from Yale University in 1929. World War II Margenau worked on the theory of microwaves and the development of duplexing systems that enabled a single radar antenna both to transmit and receive signals. He also worked on spectral line broadening, a technique used to analyse and review the dynamics of the atomic bombing of Hiroshima. Philosophy and history of science Margenau wrote extensively on science, his works including: ''Ethics and Science'', ''The Nature of Physical Reality'', ''Quantum Mechanics'' and ''Integrative Principles of Modern Thought''. He wrote in 1954 the important introduction for the classic book of Hermann von Helmholtz, On the Sensations of Tone. Fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bielefeld
Bielefeld () is a city in the Ostwestfalen-Lippe Region in the north-east of North Rhine-Westphalia, Germany. With a population of 341,755, it is also the most populous city in the administrative region (''Regierungsbezirk'') of Detmold and the 18th largest city in Germany. The historical centre of the city is situated north of the Teutoburg Forest line of hills, but modern Bielefeld also incorporates boroughs on the opposite side and on the hills. The city is situated on the ', a hiking trail which runs for 156 km along the length of the Teutoburg Forest. Bielefeld is home to a significant number of internationally operating companies, including Dr. Oetker, Gildemeister and Schüco. It has a university and several technical colleges ('' Fachhochschulen''). Bielefeld is also famous for the Bethel Institution, and for the Bielefeld conspiracy, which satirises conspiracy theories by claiming that Bielefeld does not exist. This concept has been used in the town's marke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ranges as microwaves; the above broad definition includes both UHF and EHF (millimeter wave) bands. A more common definition in radio-frequency engineering is the range between 1 and 100 GHz (wavelengths between 0.3 m and 3 mm). In all cases, microwaves include the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum. Frequencies in the microwave range are often referred to by their IEEE radar band designations: S, C, X, Ku, K, or Ka band, or by similar NATO or EU designations. The prefix ' in ''microwave'' is not meant to suggest a wavelength in the micrometer range. Rather, it indicates that microwaves are "small" (having shorter wavelengths), compared to the radio waves used prior to microwave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic War
Nuclear warfare, also known as atomic warfare, is a theoretical military conflict or prepared political strategy that deploys nuclear weaponry. Nuclear weapons are weapons of mass destruction; in contrast to conventional warfare, nuclear warfare can produce destruction in a much shorter time and can have a long-lasting radiological result. A major nuclear exchange would likely have long-term effects, primarily from the fallout released, and could also lead to secondary effects, such as " nuclear winter", nuclear famine and societal collapse. A global thermonuclear war with Cold War-era stockpiles, or even with the current smaller stockpiles, may lead to various scenarios including the extinction of the human race. To date, the only use of nuclear weapons in armed conflict occurred in 1945 with the American atomic bombings of Hiroshima and Nagasaki. On August 6, 1945, a uranium gun-type device (code name "Little Boy") was detonated over the Japanese city of Hiroshima. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter. The first test of a fission ("atomic") bomb released an amount of energy approximately equal to . The first thermonuclear ("hydrogen") bomb test released energy approximately equal to . Nuclear bombs have had yields between 10 tons TNT (the W54) and 50 megatons for the Tsar Bomba (see TNT equivalent). A thermonuclear weapon weighing as little as can release energy equal to more than . A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecumenical
Ecumenism (), also spelled oecumenism, is the concept and principle that Christians who belong to different Christian denominations should work together to develop closer relationships among their churches and promote Christian unity. The adjective ''ecumenical'' is thus applied to any initiative that encourages greater cooperation and union among Christian denominations and churches. The fact that all Christians belonging to mainstream Christian denominations profess faith in Jesus as Lord and Saviour over a believer's life, believe that the Bible is the infallible, inerrant and inspired word of God (John 1:1), and receive baptism according to the Trinitarian formula is seen as being a basis for ecumenism and its goal of Christian unity. Ecumenists cite John 17:20-23 as the biblical grounds of striving for church unity, in which Jesus prays that Christians "may all be one" in order "that the world may know" and believe the Gospel message. In 1920, the Ecumenical Patriar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Council Of Churches
The World Council of Churches (WCC) is a worldwide Christian inter-church organization founded in 1948 to work for the cause of ecumenism. Its full members today include the Assyrian Church of the East, the Oriental Orthodox Churches, most jurisdictions of the Eastern Orthodox Church, the Old Catholic Church, the Lutheran churches, the Anglican Communion, the Mennonite churches, the Methodist churches, the Moravian Church, Mar Thoma Syrian Church and the Reformed churches, as well as the Baptist World Alliance and Pentecostal churches. Notably, the Catholic Church is not a full member, although it sends delegates to meetings who have observer status. The WCC describes itself as "a worldwide fellowship of 349 global, regional and sub-regional, national and local churches seeking unity, a common witness and Christian service". It has no head office as such, but its administrative centre is at the Ecumenical Centre in Geneva, Switzerland. The organization's members includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William James
William James (January 11, 1842 – August 26, 1910) was an American philosopher, historian, and psychologist, and the first educator to offer a psychology course in the United States. James is considered to be a leading thinker of the late 19th century, one of the most influential philosophers of the United States, and the "Father of American psychology". Along with Charles Sanders Peirce, James established the philosophical school known as pragmatism, and is also cited as one of the founders of functional psychology. A '' Review of General Psychology'' analysis, published in 2002, ranked James as the 14th most eminent psychologist of the 20th century. A survey published in ''American Psychologist'' in 1991 ranked James's reputation in second place, after Wilhelm Wundt, who is widely regarded as the founder of experimental psychology. Career James interacted with a wide array of writers and scholars throughout his life, including his godfather Ralph Waldo Emerson, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indeterminism
Indeterminism is the idea that events (or certain events, or events of certain types) are not caused, or do not cause deterministically. It is the opposite of determinism and related to chance. It is highly relevant to the philosophical problem of free will, particularly in the form of libertarianism. In science, most specifically quantum theory in physics, indeterminism is the belief that no event is certain and the entire outcome of anything is probabilistic. Heisenberg's uncertainty principle and the " Born rule", proposed by Max Born, are often starting points in support of the indeterministic nature of the universe. Indeterminism is also asserted by Sir Arthur Eddington, and Murray Gell-Mann. Indeterminism has been promoted by the French biologist Jacques Monod's essay "'' Chance and Necessity''". The physicist-chemist Ilya Prigogine argued for indeterminism in complex systems. Necessary but insufficient causation Indeterminists do not have to deny that causes e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensations Of Tone
''On the Sensations of Tone as a Physiological Basis for the Theory of Music'' (German ), commonly referred to as ''Sensations of Tone'', is a foundational work on music acoustics and the perception of sound by Hermann von Helmholtz. The first German edition was published in 1863. The English translation by Alexander J. Ellis was first published in 1875 (the first English edition was from the 1870 third German edition; the second English edition from the 1877 fourth German edition was published in 1885; the 1895 and 1912 third and fourth English editions were reprints of the second edition). The editions translated into English contain detailed commentary and notes (titled "Additions by the Translator") by Ellis. Helmholtz declared that he started working on his book in 1854, which concluded in 1862. Helmholtz started publishing on acoustics in 1852. His last article on acoustics was in 1878, reviewing the book by Lord Rayleigh (Theory of Sound). Therefore, Helmholtz published ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Von Helmholtz
Hermann Ludwig Ferdinand von Helmholtz (31 August 1821 – 8 September 1894) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The Helmholtz Association, the largest German association of research institutions, is named in his honor. In the fields of physiology and psychology, Helmholtz is known for his mathematics concerning the eye, theories of vision, ideas on the visual perception of space, color vision research, the sensation of tone, perceptions of sound, and empiricism in the physiology of perception. In physics, he is known for his theories on the conservation of energy, work in electrodynamics, chemical thermodynamics, and on a mechanical foundation of thermodynamics. As a philosopher, he is known for his philosophy of science, ideas on the relation between the laws of perception and the laws of nature, the science of aesthetics, and ideas on the civilizing powe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Bombing Of Hiroshima
The United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August 1945, respectively. The two bombings killed between 129,000 and 226,000 people, most of whom were civilians, and remain the only use of nuclear weapons in armed conflict so far. In the final year of World War II, the Allies prepared for a costly invasion of the Japanese mainland. This undertaking was preceded by a conventional and firebombing campaign that devastated 64 Japanese cities. The war in the European theatre concluded when Germany surrendered on 8 May 1945, and the Allies turned their full attention to the Pacific War. By July 1945, the Allies' Manhattan Project had produced two types of atomic bombs: "Fat Man", a plutonium implosion-type nuclear weapon; and "Little Boy", an enriched uranium gun-type fission weapon. The 509th Composite Group of the United States Army Air Forces was trained and equipped with the specialized Silverplate version of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Line Broadening
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules. These "fingerprints" can be compared to the previously collected ones of atoms and molecules, and are thus used to identify the atomic and molecular components of stars and planets, which would otherwise be impossible. Types of line spectra Spectral lines are the result of interaction between a quantum system (usually atoms, but sometimes molecules or atomic nuclei) and a single photon. When a photon has about the right amount of energy (which is connected to its frequency) to allow a change in the energy state of the system (in the case of an atom this is usually an electron changing orbitals), the photon is absorbed. Then the energy will be spontaneously re-emitted, either as one photon at the same frequen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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