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Optical Sound
Optical sound is a means of storing sound recordings on transparent film. Originally developed for military purposes, the technology first saw widespread use in the 1920s as a sound-on-film format for motion pictures. Optical sound eventually superseded all other sound film technologies until the advent of digital sound became the standard in cinema projection booths. Optical sound has also been used for multitrack recording and for creating effects in some musical synthesizers. 1914-1921: Naval and military use Building on the principle first demonstrated by the Photophone of Alexander Graham Bell in 1880, optical sound was developed by several inventors with an interest in wireless communication through transmission of light, primarily for nautical, ship-to-ship use. The idea was that sound pulses could be converted into light pulses, beamed out from one ship and picked up by another, where the light pulses would then be reconverted into sound. A pioneer in this technology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoelectric
The photoelectric effect is the emission of electrons from a material caused by electromagnetic radiation such as ultraviolet light. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, solid state, and quantum chemistry to draw inferences about the properties of atoms, molecules and solids. The effect has found use in electronic devices specialized for light detection and precisely timed electron emission. The experimental results disagree with classical electromagnetism, which predicts that continuous light waves transfer energy to electrons, which would then be emitted when they accumulate enough energy. An alteration in the intensity of light would theoretically change the kinetic energy of the emitted electrons, with sufficiently dim light resulting in a delayed emission. The experimental results instead show that electrons are dislodged only when the light exceeds a certain frequency—regardless of the light's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calvin Coolidge
Calvin Coolidge (born John Calvin Coolidge Jr.; ; July 4, 1872January 5, 1933) was the 30th president of the United States, serving from 1923 to 1929. A Republican Party (United States), Republican lawyer from Massachusetts, he previously served as the 29th Vice President of the United States, vice president from 1921 to 1923 under President Warren G. Harding, and as the 48th governor of Massachusetts from 1919 to 1921. Coolidge gained a reputation as a Libertarian conservatism, small-government conservative with a taciturn personality and dry sense of humor that earned him the nickname "Silent Cal". Coolidge began his career as a member of the Massachusetts House of Representatives, Massachusetts State House. He rose up the ranks of Massachusetts politics and was elected governor 1918 Massachusetts gubernatorial election, in 1918. As governor, Coolidge ran on the record of fiscal conservatism, strong support for women's suffrage, and vague opposition to Prohibition in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Electric
General Electric Company (GE) was an American Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1892, incorporated in the New York (state), state of New York and headquartered in Boston. Over the years, the company had multiple divisions, including GE Aerospace, aerospace, GE Power, energy, GE HealthCare, healthcare, lighting, locomotives, appliances, and GE Capital, finance. In 2020, GE ranked among the Fortune 500, ''Fortune'' 500 as the 33rd largest firm in the United States by gross revenue. In 2023, the company was ranked 64th in the Forbes Global 2000, ''Forbes'' Global 2000. In 2011, GE ranked among the Fortune 20 as the 14th most profitable company, but later very severely underperformed the market (by about 75%) as its profitability collapsed. Two employees of GE—Irving Langmuir (1932) and Ivar Giaever (1973)—have been awarded the Nobel Prize. From 1986 until 2013, GE was the owner of the NBC television network through its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Language
Greek (, ; , ) is an Indo-European languages, Indo-European language, constituting an independent Hellenic languages, Hellenic branch within the Indo-European language family. It is native to Greece, Cyprus, Italy (in Calabria and Salento), southern Albania, and other regions of the Balkans, Caucasus, the Black Sea coast, Asia Minor, and the Eastern Mediterranean. It has the list of languages by first written accounts, longest documented history of any Indo-European language, spanning at least 3,400 years of written records. Its writing system is the Greek alphabet, which has been used for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary. The Greek language holds a very important place in the history of the Western world. Beginning with the epics of Homer, ancient Greek literature includes many works of lasting importance in the European canon. Greek is also the language in which many of the foundational texts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pallophotophone
{{short description, Photographic sound recording system The pallophotophone (coined from the Greek root words ''pallo'', to oscillate or shake; ''photo'', light; and ''phone'', sound, therefore literally meaning "shaking light sound") was a photographic sound recording and playback system developed by General Electric researcher Charles A. Hoxie circa 1922. The RCA Photophone sound-on-film system for motion pictures was later derived from it. System The pallophotophone was an optical sound system which could record and play back audio tracks on a strip of 35 mm black-and-white photographic film.''Radio Digest'', September 15, 1923, p.13 shows three tracks on perforated 35 mm film; the surviving examples recently in the news, from later years (1929–1931), are on unperforat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles A
Charles is a masculine given name predominantly found in English and French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic name (in runic alphabet) or ''*karilaz'' (in Latin alphabet), whose meaning was "free man". The Old English descendant of this word was '' Ċearl'' or ''Ċeorl'', as the name of King Cearl of Mercia, that disappeared after the Norman conquest of England. The name was notably borne by Charlemagne (Charles the Great), and was at the time Latinized as ''Karolus'' (as in ''Vita Karoli Magni''), later also as '' Carolus''. Etymology The name's etymology is a Common Germanic noun ''*karilaz'' meaning "free man", which survives in English as churl (James (wikt:Appendix:Proto-Indo-European/ǵerh₂-">ĝer-, where the ĝ is a palatal consonant, meaning "to rub; to be old; grain." An old man has been worn away and is now grey with age. In some Slavic languages, the name ''Drago (given name), Drago'' (and variants: ''Drago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting took place mainly in European theatre of World War I, Europe and the Middle Eastern theatre of World War I, Middle East, as well as in parts of African theatre of World War I, Africa and the Asian and Pacific theatre of World War I, Asia-Pacific, and in Europe was characterised by trench warfare; the widespread use of Artillery of World War I, artillery, machine guns, and Chemical weapons in World War I, chemical weapons (gas); and the introductions of Tanks in World War I, tanks and Aviation in World War I, aircraft. World War I was one of the List of wars by death toll, deadliest conflicts in history, resulting in an estimated World War I casualties, 10 million military dead and more than 20 million wounded, plus some 10 million civilian de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Edison
Thomas Alva Edison (February11, 1847October18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventions, which include the phonograph, the motion picture camera, and early versions of the electric Incandescent light bulb, light bulb, have had a widespread impact on the modern industrial society, industrialized world. He was one of the first inventors to apply the principles of organized science and teamwork to the process of invention, working with many researchers and employees. He established the first industrial research laboratory. Edison was raised in the American Midwest. Early in his career he worked as a telegraph operator, which inspired some of his earliest inventions. In 1876, he established his first laboratory facility in Menlo Park, New Jersey, where many of his early inventions were developed. He later established a botanical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of red light (the longest waves in the visible spectrum), so IR is invisible to the human eye. IR is generally (according to ISO, CIE) understood to include wavelengths from around to . IR is commonly divided between longer-wavelength thermal IR, emitted from terrestrial sources, and shorter-wavelength IR or near-IR, part of the solar spectrum. Longer IR wavelengths (30–100 μm) are sometimes included as part of the terahertz radiation band. Almost all black-body radiation from objects near room temperature is in the IR band. As a form of EMR, IR carries energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classified Information
Classified information is confidential material that a government deems to be sensitive information which must be protected from unauthorized disclosure that requires special handling and dissemination controls. Access is restricted by law or regulation to particular groups of individuals with the necessary security clearance with a need to know. A formal security clearance is required to view or handle classified material. The clearance process requires a satisfactory background investigation. Documents and other information must be properly marked "by the author" with one of several (hierarchical) levels of sensitivity—e.g. Confidential (C), Secret (S), and Top Secret (S). All classified documents require designation markings on the technical file which is usually located either on the cover sheet, header and footer of page. The choice of level is based on an impact assessment; governments have their own criteria, including how to determine the classification of an inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
