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Brown Note
The brown note, also sometimes called the brown frequency or brown noise, is a hypothetical infrasonic frequency capable of causing fecal incontinence by creating acoustic resonance in the human bowel. The name is a metonym for the common color of human faeces. Attempts to demonstrate the existence of a "brown note" using sound waves transmitted through the air have failed. Frequencies supposedly involved are between 5 and 9 Hz, which are below the lower frequency limit of human hearing. High-power sound waves below 20 Hz are felt in the body, not heard by the ear as sound. Physiological effects of low frequency vibration Air is a very inefficient medium for transferring low frequency vibration from a transducer to the human body. Mechanical connection of the vibration source to the human body, however, provides a potentially dangerous combination. The U.S. space program, worried about the harmful effects of rocket flight on astronauts, ordered vibration tests that used cock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrasound
Infrasound, sometimes referred to as low status sound, describes sound waves with a frequency below the lower limit of human audibility (generally 20 Hz). Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. The ear is the primary organ for sensing low sound, but at higher intensities it is possible to feel infrasound vibrations in various parts of the body. The study of such sound waves is sometimes referred to as infrasonics, covering sounds beneath 20 Hz down to 0.1 Hz (and rarely to 0.001 Hz). People use this frequency range for monitoring earthquakes and volcanoes, charting rock and petroleum formations below the earth, and also in ballistocardiography and seismocardiography to study the mechanics of the heart. Infrasound is characterized by an ability to get around obstacles with little dissipation. In music, acoustic waveguide methods, such as a large pipe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microphone
A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public events, motion picture production, live and recorded audio engineering, sound recording, two-way radios, megaphones, and radio and television broadcasting. They are also used in computers for recording voice, speech recognition, VoIP, and for other purposes such as ultrasonic sensors or knock sensors. Several types of microphone are used today, which employ different methods to convert the air pressure variations of a sound wave to an electrical signal. The most common are the dynamic microphone, which uses a coil of wire suspended in a magnetic field; the condenser microphone, which uses the vibrating diaphragm as a capacitor plate; and the contact microphone, which uses a crystal of piezoelectric material. Microphones typically n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urban Legends
An urban legend (sometimes contemporary legend, modern legend, urban myth, or urban tale) is a genre of folklore comprising stories or fallacious claims circulated as true, especially as having happened to a "friend of a friend" or a family member, often with horrifying, humorous, or cautionary elements. These legends can be entertaining but often concern mysterious peril or troubling events, such as disappearances and strange objects or entities. Urban legends may confirm moral standards, reflect prejudices, or be a way to make sense of societal anxieties. Urban legends in the past were most often circulated orally, but now can also be spread by any media. This includes newspapers, mobile news apps, e-mail, and most often, social media. Some urban legends have passed through the years/decades with only minor changes, in where the time period takes place. Generic urban legends are often altered to suit regional variations, but the lesson or moral remains majorly the same. O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges. Acoustics Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gasses, liquids, and solids including vibration, sound, ultrasound, and infrasound. A scientist who works in the field of acoustics is an ''acoustician'', while someone working in the field of acoustica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Worldwide Recorder Concert
"World Wide Recorder Concert" (also known as "The Brown Noise") is the seventeenth and final episode of the third season of the animated television series ''South Park'' and the 48th episode of the series overall. It was originally broadcast on January 12, 2000. In the episode, the boys feud with children from New York at a gathering of elementary school students for a recorder concert. Meanwhile, Mr. Garrison confronts his father, whom he believes had neglected him in childhood. Plot synopsis Four million children, including those from Mr. Garrison's class, are scheduled to play "My Country, 'Tis of Thee" at the televised Worldwide Recorder Concert in Oklahoma City led by Yoko Ono and Kenny G, but a flood causes the concert to be relocated to Little Rock, Mr. Garrison's hometown. This causes him considerable anxiety (as he confesses to Mr. Mackey) for he had " sexual molestation issues" with his father in the past. In Arkansas, the boys encounter a hostile group of kids from New ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tesla's Oscillator
Tesla's electro-mechanical oscillator is a steam-powered electric generator patented by Nikola Tesla in 1893. Later in life Tesla claimed one version of the oscillator caused an earthquake in New York City in 1898, gaining it the popular culture title "Tesla's earthquake machine". Description Tesla's oscillator is a reciprocating electricity generator. Steam would be forced into the oscillator, and exit through a series of ports, pushing a piston up and down that was attached to an armature, causing it to vibrate up and down at high speed, producing electricity. The casing's upper chamber had to withstand pressures of and temperatures exceeding 200 °C. Some versions used air trapped behind the piston as an "air spring", increasing efficiency. Another variation used electromagnets to control the frequency of the piston's oscillation. Tesla developed many versions of the oscillator and looked on it as a possible replacement for inefficient reciprocating steam engines used to turn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Republic XF-84H
The Republic XF-84H "Thunderscreech" was an American experimental turboprop aircraft derived from the F-84F Thunderstreak. Powered by a turbine engine that was mated to a supersonic propeller, the XF-84H had the potential of setting the unofficial air speed record for propeller-driven aircraft, but was unable to overcome aerodynamic deficiencies and engine reliability problems, resulting in the program's cancellation.Knaack, Marcelle Size. ''Encyclopedia of U.S. Air Force Aircraft and Missile Systems: Volume 1 Post-World War II Fighters 1945–1973''. Washington, D.C.: Office of Air Force History, 1978. . Design and development Although the USAF Wright Air Development Center was the key sponsor of the Republic Project 3347 turboprop fighter, the initial inception came from a U.S. Navy requirement for a carrier fighter not requiring catapult assistance.Keaveney 1987, p. 9. Originally known as XF-106 (a designation later reused for the Convair F-106), the project and its resultant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Mosquito
''The'' () is a grammatical article in English, denoting persons or things already mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with pronouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of pronoun ''thee'') when followed by a v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feraliminal Lycanthropizer
The Feraliminal Lycanthropizer is a fictional psychotechnographic machine Connor, S.''Dream Machines''(London: Open Humanities Press, 2017), p. 131. invented by American writer David Woodard, whose 1990 pamphlet of the same title speculates on its history and purpose.Woodard, D."Feraliminal Lycanthropizer"(San Francisco: Plecid General Outreach, 1990). The brief, anonymously published work describes a vibration referred to as "thanato-auric waves", which the machine electrically generates by combining three infrasonic sine waves (3 Hz, 9 Hz and 0.56 Hz) with tape loops of unspecified spoken text (two beyond the threshold of decipherability, and two beneath the threshold). Sergeant, J."Sonic Doom" ''Fortean Times'', December 2001. Woodard describes the machine as "a low frequency thanato-auric wave generator" that is "known for its use by the Nazis and for its animalizing effects on human subjects tested within measurable vibratory proximity". The machine creates vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acoustic Resonance
Acoustic resonance is a phenomenon in which an acoustic system amplifies sound waves whose frequency matches one of its own natural frequencies of vibration (its ''resonance frequencies''). The term "acoustic resonance" is sometimes used to narrow mechanical resonance to the frequency range of human hearing, but since acoustics is defined in general terms concerning vibrational waves in matter, acoustic resonance can occur at frequencies outside the range of human hearing. An acoustically resonant object usually has more than one resonance frequency, especially at harmonics of the strongest resonance. It will easily vibrate at those frequencies, and vibrate less strongly at other frequencies. It will "pick out" its resonance frequency from a complex excitation, such as an impulse or a wideband noise excitation. In effect, it is filtering out all frequencies other than its resonance. Acoustic resonance is an important consideration for instrument builders, as most acoustic i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lung
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the air and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their different muscles to support and foster breathing. In earlier tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the main muscle of respiration that drives breathing is the diaphragm. The lungs also provide airflow that makes vocal sounds including human speech possible. Humans have two lungs, one on the left and on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Pressure
Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average or equilibrium) atmospheric pressure, caused by a sound wave. In air, sound pressure can be measured using a microphone, and in water with a hydrophone. The SI unit of sound pressure is the pascal (Pa). Mathematical definition A sound wave in a transmission medium causes a deviation (sound pressure, a ''dynamic'' pressure) in the local ambient pressure, a ''static'' pressure. Sound pressure, denoted ''p'', is defined by p_\text = p_\text + p, where * ''p''total is the total pressure, * ''p''stat is the static pressure. Sound measurements Sound intensity In a sound wave, the complementary variable to sound pressure is the particle velocity. Together, they determine the sound intensity of the wave. ''Sound intensity'', denoted I and measured in W· m−2 in SI units, is defined by \mathbf I = p \mathbf v, where * ''p'' is the sound pressure, * v is the particle velocity. Acoustic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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