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History Of Radio
The early history of radio is the history of technology that produces and uses radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy". Later radio history increasingly involves matters of broadcasting. Discovery In an 1864 presentation, published in 1865, James Clerk Maxwell proposed theories of electromagnetism and mathematical proofs demonstrating that light, radio and x-rays were all types of electromagnetic waves propagating through free space. Between 1886 and 1888 Heinrich Rudolf Hertz published the results of experiments wherein he was able to transmit electromagnetic waves (radio waves) through the air, proving Maxwell's electromagnetic theory. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Einstein With Engineers And Scientists - RCA Radio Station - Hagley Archives - Restoration1
Albert may refer to: Companies * Albert Computers, Inc., a computer manufacturer in the 1980s * Albert Czech Republic, a supermarket chain in the Czech Republic * Albert Heijn, a supermarket chain in the Netherlands * Albert Market, a street market in The Gambia * Albert Music, an Australian music company now known as Alberts ** Albert Productions, a record label * Albert (organisation), an environmental organisation concerning film and television productions Entertainment * ''Albert'' (1985 film), a Czechoslovak film directed by František Vláčil * ''Albert'' (2015 film), a film by Karsten Kiilerich * ''Albert'' (2016 film), an American TV movie * ''Albert'' (album), by Ed Hall, 1988 * "Albert" (short story), by Leo Tolstoy * Albert (comics), a character in Marvel Comics * Albert (''Discworld''), a character in Terry Pratchett's ''Discworld'' series * Albert, a character in Dario Argento's 1977 film ''Suspiria'' People * Albert (given name) * Albert (surname) * Princ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coherer
The coherer was a primitive form of radio signal detector used in the first radio receivers during the wireless telegraphy era at the beginning of the 20th century. Its use in radio was based on the 1890 findings of French physicist Édouard Branly and adapted by other physicists and inventors over the next ten years. The device consists of a tube or capsule containing two electrodes spaced a small distance apart with loose metal filings in the space between. When a radio frequency signal is applied to the device, the metal particles would cling together or " cohere", reducing the initial high resistance of the device, thereby allowing a much greater direct current to flow through it. In a receiver, the current would activate a bell, or a Morse paper tape recorder to make a record of the received signal. The metal filings in the coherer remained conductive after the signal (pulse) ended so that the coherer had to be "decohered" by tapping it with a clapper actuated by an electro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waveguide (electromagnetism)
In radio-frequency engineering and communications system engineering, communications engineering, a waveguide is a hollow metal pipe used to carry radio waves. This type of waveguide is used as a transmission line mostly at microwave frequencies, for such purposes as connecting microwave transmitters and Radio receiver, receivers to their Antenna (radio), antennas, in equipment such as microwave ovens, radar sets, satellite communications, and microwave radio links. The electromagnetic waves in a (metal-pipe) waveguide may be imagined as travelling down the guide in a zig-zag path, being repeatedly reflected between opposite walls of the guide. For the particular case of rectangular waveguide, it is possible to base an exact analysis on this view. Propagation in a dielectric waveguide may be viewed in the same way, with the waves confined to the dielectric by total internal reflection at its surface. Some structures, such as non-radiative dielectric waveguides and the Goubau li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jagadish Chandra Bose
Sir Jagadish Chandra Bose (; ; 30 November 1858 – 23 November 1937) was a polymath with interests in biology, physics and writing science fiction. He was a pioneer in the investigation of radio microwave optics, made significant contributions to botany, and was a major force behind the expansion of experimental science on the Indian subcontinent. Bose is considered the father of Bengali science fiction. Bose (crater), A crater on the Moon was named in his honour. He founded the Bose Institute, a premier research institute in India and also one of its oldest. Established in 1917, the institute was the first interdisciplinary research centre in Asia. He served as the Director of Bose Institute from its inception until his death. Born in Mymensingh, Bengal Presidency (present-day Bangladesh), during British Raj, British governance of India, Bose graduated from St. Xavier's College, Calcutta (now Kolkata, West Bengal, India). Prior to his enrollment at St. Xavier's College, Calcut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyotr Lebedev
Pyotr Nikolaevich Lebedev (; 24 February 1866 – 1 March 1912) was a Russian physicist. His name was also transliterated as Peter Lebedew and Peter Lebedev. Lebedev was the creator of the first scientific school in Russia. Career Lebedev made his doctoral degree in Strasbourg under the supervision of August Kundt in 1887–1891. In 1891, he started working in Moscow State University in the group of Alexander Stoletov. There he made his famous experimental studies of electromagnetic waves. Along with Indian physicist Jagadish Chandra Bose he was one of the first to investigate millimeter waves, generating 50 GHz (6 mm) microwaves beginning in 1895 with a spark oscillator made of two platinum cylinders 1.5 cm long and 0.5 diameter immersed in kerosene at the focus of a parabolic reflector, and detecting the waves with an iron- constantan thermocouple detector.A. A. Kostenko, A. I. Nosich, P. F. Goldsmith, "Historical background and development of Soviet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Augusto Righi
Augusto Righi (; 27 August 1850 – 8 June 1920) was an Italian physicist who was one of the first scientists to produce microwaves. Biography Born in Bologna, Righi was educated in his home town, taught physics at Bologna Technical College between 1873 and 1880, and left to take up the newly established chair of physics at the University of Palermo. He was a professor of physics at the University of Padua (1885–89) and later returned to a professorship at the University of Bologna. Righi's early research, conducted in Bologna between 1872 and 1880, was primarily in electrostatics. He invented an induction electrometer, with the help of Matthew Van Schaeick of the Humboldt University of Berlin, in 1872, capable of detecting and amplifying small electrostatic charges, formulated mathematical descriptions of vibrational mode, vibrational motion, and discovered magnetic hysteresis in 1880. Whilst an ordinary professor in physics at the University of Palermo, he studied the conduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasioptics
Quasioptics concerns the propagation of electromagnetic radiation where the wavelength is comparable to the size of the optical components (e.g. lenses, mirrors, and apertures) and hence diffraction effects may become significant. It commonly describes the propagation of Gaussian beams where the beam width is comparable to the wavelength. This is in contrast to geometrical optics, where the wavelength is small compared to the relevant length scales. Quasioptics is so named because it represents an intermediate regime between conventional optics and electronics, and is often relevant to the description of signals in the far-infrared or terahertz region of the electromagnetic spectrum. It represents a simplified version of the more rigorous treatment of physical optics. Quasi-optical systems may also operate at lower frequencies such as millimeter wave, microwave, and even lower. See also *Optoelectronics Optoelectronics (or optronics) is the study and application of electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSM V83 D416 Oliver Joseph Lodge
PSM, an acronym, may refer to: Organizations * Pakistan School Muscat, a Pakistani co-educational institute in Oman * Palestine Solidarity Movement, a student organization in the United States * Panhellenic Socialist Movement, a centre-left party in Greece * Parti Socialiste Mauricien, a political party in Mauritius, founded by Harish Boodhoo * Parti Sosialis Malaysia, a socialist political party in Malaysia * Sepaktakraw Association of Malaysia (; PSM), a national governing body in Malaysia * Photographic Society of Madras, a not for profit organisation involved in promoting photography, in Chennai * PlayStation: The Official Magazine, a magazine originally known as PlayStation Magazine or PSM * Ponce School of Medicine, a post-graduate medical school located in Ponce, Puerto Rico * Power Systems Manufacturing, a subsidiary of Alstom, specializing in aftermarket gas turbine servicing for power generating industry. * ''Poznańska Spółdzielnia Mieszkaniowa'', a housing cooper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarendon Laboratory
The Clarendon Laboratory, located on Parks Road within the Science Area in Oxford, England (not to be confused with the Clarendon Building, also in Oxford), is part of the Department of Physics at Oxford University. It houses the atomic and laser physics, condensed matter physics, and biophysics groups within the Department, although four other Oxford Physics groups are not based in the Clarendon Lab. The Oxford Centre for Quantum Computation is also housed in the laboratory. Buildings The Clarendon Laboratory consists of two adjoining buildings, the Lindemann Building (named after Frederick Lindemann, 1st Viscount Cherwell) and the Grade II listed Townsend Building (named after Sir John Sealy Townsend). The Beecroft Building (named after Adrian Beecroft) is now immediately in front of the Lindemann Building, completed in 2018 and designed by Hawkins\Brown, with a budget of approximately £40 million. History The Clarendon is named after Edward Hyde, 1st Earl of Clarend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Wave
In physics, electromagnetic radiation (EMR) is a self-propagating wave of the electromagnetic field that carries momentum and radiant energy through space. It encompasses a broad spectrum, classified by frequency or its inverse, wavelength, ranging from radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. All forms of EMR travel at the speed of light in a vacuum and exhibit wave–particle duality, behaving both as waves and as discrete particles called photons. Electromagnetic radiation is produced by accelerating charged particles such as from the Sun and other celestial bodies or artificially generated for various applications. Its interaction with matter depends on wavelength, influencing its uses in communication, medicine, industry, and scientific research. Radio waves enable broadcasting and wireless communication, infrared is used in thermal imaging, visible light is essential for vision, and higher-energy radiation, such as X ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standing Wave
In physics, a standing wave, also known as a stationary wave, is a wave that oscillates in time but whose peak amplitude profile does not move in space. The peak amplitude of the wave oscillations at any point in space is constant with respect to time, and the oscillations at different points throughout the wave are in phase. The locations at which the absolute value of the amplitude is minimum are called node (physics), nodes, and the locations where the absolute value of the amplitude is maximum are called antinodes. Standing waves were first described scientifically by Michael Faraday in 1831. Faraday observed Faraday wave, standing waves on the surface of a liquid in a vibrating container. Franz Melde coined the term "standing wave" (German: ''stehende Welle'' or ''Stehwelle'') around 1860 and demonstrated the phenomenon in his classic experiment with vibrating strings. This phenomenon can occur because the medium is moving in the direction opposite to the movement of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interference (wave Motion)
In physics, interference is a phenomenon in which two coherent waves are combined by adding their intensities or displacements with due consideration for their phase difference. The resultant wave may have greater amplitude (constructive interference) or lower amplitude (destructive interference) if the two waves are in phase or out of phase, respectively. Interference effects can be observed with all types of waves, for example, light, radio, acoustic, surface water waves, gravity waves, or matter waves as well as in loudspeakers as electrical waves. Etymology The word ''interference'' is derived from the Latin words ''inter'' which means "between" and ''fere'' which means "hit or strike", and was used in the context of wave superposition by Thomas Young in 1801. Mechanisms The principle of superposition of waves states that when two or more propagating waves of the same type are incident on the same point, the resultant amplitude at that point is equal to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
