1.
Pulley
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A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable, supporting shell is referred to as a block. A pulley may also be called a sheave or drum and may have a groove or grooves between two flanges around its circumference. The drive element of a system can be a rope, cable, belt. Hero of Alexandria identified the pulley as one of six simple machines used to lift weights, pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to power from one rotating shaft to another. A set of pulleys assembled so that they rotate independently on the axle from a block. Two blocks with an attached to one of the blocks. A block and tackle is assembled so one block is attached to fixed mounting point, the ideal mechanical advantage of the block and tackle is equal to the number of parts of the rope that support the moving block. This system is included in the list of simple machines identified by Renaissance scientists, if the rope and pulley system does not dissipate or store energy, then its mechanical advantage is the number of parts of the rope that act on the load. This can be shown as follows, consider the set of pulleys that form the moving block and the parts of the rope that support this block. If there are p of these parts of the supporting the load W. This means the force on the rope is T=W/p. Thus, the block and tackle reduces the force by the factor p. The simplest theory of operation for a pulley system assumes that the pulleys and lines are weightless, and it is also assumed that the lines do not stretch. In equilibrium, the forces on the block must sum to zero. In addition the tension in the rope must be the same for each of its parts and this means that the two parts of the rope supporting the moving block must each support half the load. These are different types of systems, Fixed, A fixed pulley has an axle mounted in bearings attached to a supporting structure. A fixed pulley changes the direction of the force on a rope or belt that moves along its circumference, mechanical advantage is gained by combining a fixed pulley with a movable pulley or another fixed pulley of a different diameter
2.
Musical instrument
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A musical instrument is an instrument created or adapted to make musical sounds. In principle, any object that produces sound can be a musical instrument—it is through purpose that the object becomes a musical instrument, the history of musical instruments dates to the beginnings of human culture. Early musical instruments may have used for ritual, such as a trumpet to signal success on the hunt. Cultures eventually developed composition and performance of melodies for entertainment, Musical instruments evolved in step with changing applications. The date and origin of the first device considered an instrument is disputed. The oldest object that some refer to as a musical instrument. Some consensus dates early flutes to about 37,000 years ago, many early musical instruments were made from animal skins, bone, wood, and other non-durable materials. Musical instruments developed independently in many populated regions of the world, however, contact among civilizations caused rapid spread and adaptation of most instruments in places far from their origin. By the Middle Ages, instruments from Mesopotamia were in maritime Southeast Asia, development in the Americas occurred at a slower pace, but cultures of North, Central, and South America shared musical instruments. By 1400, musical instrument development slowed in areas and was dominated by the Occident. Musical instrument classification is a discipline in its own right, Instruments can be classified by their effective range, their material composition, their size, etc. However, the most common method, Hornbostel-Sachs, uses the means by which they produce sound. The academic study of instruments is called organology. Once humans moved from making sounds with their bodies—for example, by using objects to create music from sounds. Primitive instruments were designed to emulate natural sounds, and their purpose was ritual rather than entertainment. The concept of melody and the pursuit of musical composition were unknown to early players of musical instruments. A player sounding a flute to signal the start of a hunt does so without thought of the notion of making music. Musical instruments are constructed in an array of styles and shapes
3.
Laboratory
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A laboratory is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratories used for scientific research take many forms because of the requirements of specialists in the various fields of science. A physics laboratory might contain a particle accelerator or vacuum chamber, a chemist or biologist might use a wet laboratory, while a psychologists laboratory might be a room with one-way mirrors and hidden cameras in which to observe behavior. In some laboratories, such as commonly used by computer scientists. Scientists in other fields will use other types of laboratories. Engineers use laboratories as well to design, build, and test technological devices, scientific laboratories can be found as research and learning spaces in schools and universities, industry, government, or military facilities, and even aboard ships and spacecraft. Early instances of laboratories recorded in English involved alchemy and the preparation of medicines, larger or more sophisticated equipment is generally called a scientific instrument. Both laboratory equipment and scientific instruments are increasingly being designed and shared using open hardware principles, open source labs use open source scientific hardware. The title of laboratory is used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories. In many labs, though, hazards are present, in laboratories where dangerous conditions might exist, safety precautions are important. Rules exist to minimize the risk, and safety equipment is used to protect the lab user from injury or to assist in responding to an emergency. This standard is referred to as the Laboratory Standard. Under this standard, a laboratory is required to produce a Chemical Hygiene Plan which addresses the specific hazards found in its location, the CHP must be reviewed annually. Many schools and businesses employ safety, health, and environmental specialists, such as a Chemical Hygiene Officer to develop, manage, and evaluate their CHP. Additionally, third party review is used to provide an objective outside view which provides a fresh look at areas. An important element of such audits is the review of regulatory compliance, training is critical to the ongoing safe operation of the laboratory facility. Educators, staff and management must be engaged in working to reduce the likelihood of accidents, injuries, efforts are made to ensure laboratory safety videos are both relevant and engaging. The dictionary definition of laboratory at Wiktionary Media related to Laboratory at Wikimedia Commons Nobel Laureates Interactive 360° Laboratories
4.
Fingerboard
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The fingerboard is an important component of most stringed instruments. It is a thin, long strip of material, usually wood, the strings run over the fingerboard, between the nut and bridge. To play the instrument, a musician presses strings down to the fingerboard to change the vibrating length and this is called stopping the strings. Depending on the instrument and the style of music, the musician may pluck, on some instruments, notes can be sounded by the fretting hand alone, such as with hammer ons, an electric guitar technique. The word fingerboard in other languages sometimes occurs in musical directions, in particular, the direction sul tasto for bowed string instruments to play with the bow above the fingerboard. This reduces the prominence of upper harmonics, giving a more ethereal tone, a fingerboard may be fretted, having raised strips of hard material perpendicular to the strings, which the player presses the strings against to stop the strings. On modern guitars, frets are made of metal. Frets let the player stop the string consistently in the same place, as well, frets do not dampen string vibrations as much as fingers alone on an unfretted fingerboard. Frets may be fixed, as on a guitar or mandolin, or movable, fingerboards may also be unfretted, as they usually are on bowed instruments, where damping by the finger is of little consequence because of the sustained stimulation of the strings by the bow. Unfretted fingerboards allow a more control over subtle changes in pitch than fretted boards. Fingerboards may also be, though uncommon, a hybrid of these two, such a construction is seen on the sitar, where arched frets attach at the edges of a smooth fingerboard, unfrettable strings run inside the frets, while frettable ones run outside. A double dot or some other variation marks the 12th fret, variations on the standard dot shape can make a guitar more distinctive. Position markers are sometimes made luminescent to make more visible on stage. Position markers are sometimes repeated on the edge of the fingerboard for easy viewing. Over time, strings wear frets down, which can cause buzzing, fixing this occasionally requires replacing the frets—but more often they just need dressing. In fret dressing, a luthier levels and polishes the frets, stainless steel guitar frets may never need dressing, because of the density of the material. Not having frets carefully and properly aligned with the fingerboard can cause severe intonation issues, the ultimate way of determining the source of a buzz and detuning problem is to measure the levelness of the frets. A straightedge positioned on the neck in the lie of one of the strings should show nearly level frets, on bowed string instruments, the fingerboard is usually made of ebony, rosewood or other hardwood
5.
String (music)
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A string is the vibrating element that produces sound in string instruments such as the guitar, harp, piano, and members of the violin family. Strings are lengths of a material that a musical instrument holds under tension so that they can vibrate freely. Wound strings have a core of one material, with an overwinding of other materials and this is to make the string vibrate at the desired pitch, while maintaining a low profile and sufficient flexibility for playability. This enabled stringed instruments to be made with less thick bass strings, on string instruments that the player plucks or bows directly, this enabled instrument makers to use thinner strings for the lowest-pitched strings, which made the lower-pitch strings easier to play. The end of the string that mounts to the tuning mechanism is usually plain. Depending on the instrument, the other, fixed end may have either a plain, loop. When a ball or loop is used with a guitar, this ensures that the string stays fixed in the bridge of the guitar, when a ball or loop is used with a violin-family instrument, this keeps the string end fixed in the tailpiece. Fender Bullet strings have a cylinder for more stable tuning on guitars equipped with synchronized tremolo systems. Strings for some instruments may be wrapped with silk at the ends to protect the string, the color and pattern of the silk often identifies attributes of the string, such as manufacturer, size, intended pitch, etc. There are several varieties of wound strings available, the simplest wound strings are roundwound—with round wire wrapped in a tight spiral around either a round or hexagonal core. Such strings are usually simple to manufacture and the least expensive and they have several drawbacks, however, Roundwound strings have a bumpy surface profile that produce friction on the players fingertips. This causes squeaking sounds when the fingers slide over the strings. Roundwound strings higher friction surface profile may hasten fingerboard and fret wear, when the core is round, the winding is less secure and may rotate freely around the core, especially if the winding is damaged after use. Flatwound strings also have either a round or hex core, however, the winding wire has a rounded square cross-section that has a shallower profile when tightly wound. This makes for more playing, and decreased wear for frets. Squeaking sounds due to fingers sliding along the strings are also decreased significantly, flatwound strings also have a longer playable life because of smaller grooves for dirt and oil to build up in. On the other hand, flatwound strings sound less bright than roundwounds, flatwounds also usually cost more than roundwounds because of less demand, less production, and higher overhead costs. Manufacturing is also difficult, as precise alignment of the flat sides of the winding must be maintained
6.
Bridge (instrument)
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Most stringed instruments produce their sound through the application of energy to the strings, which sets them into vibratory motion. The strings alone, however, produce only a faint sound because they displace only a volume of air as they vibrate. Consequently, the sound of the strings alone requires impedance matching to the air by transmitting their vibrations to a larger surface area capable of displacing larger volumes of air. This calls for an arrangement that allows for the strings to vibrate freely, a bridge is the customary means by which this is accomplished. Typically, the bridge is perpendicular to the strings and larger surface with the tension of the strings pressing down on the bridge and thus on the larger surface beneath it. That larger, more acoustically responsive surface may be coupled to a sound chamber—an enclosure such as the body of a guitar or violin—that provides resonance that helps amplify the sound, alternatively, a bridge may consist of multiple parts. One common form is a bridge that incorporates a separate bearing surface on which the strings rest and this is often of a material harder than the bridge itself, such as bone, ivory, high-density plastic, or metal. A classical guitar saddle sits loosely in the bridge and is kept there by string tension. The saddle has shallow grooves in it, at least for the treble strings, yet another type of multi-part bridge is common on instruments whose sound plate is curved rather than flat. Instruments of this type, such as guitars and mandolins, often have a bridge with a base. On classical and flat-top guitars the bridge is glued to the top, a bridge held on to the top by string tension, as in archtop guitars, is known as a floating bridge, and requires a separate tailpiece to anchor the strings. The bridge must transfer vibration to the board or other amplifying surface. As the strings are set in motion, it does this by bending to and this causes the sounding board to vibrate at the same frequency as the string producing a wave-like motion and an audible sound. Bridges are designed to hold the strings at a height above the fingerboard of the instrument. Bridge height may be fixed or alterable, in addition to supporting the strings and transmitting their vibrations, the bridge also controls the spacing between strings with shallow grooves cut in the bridge or its saddle. The strings sit in grooves, thus are held in their proper lateral position. The nut, at the end of the instrument from the bridge or tailpiece. Bridges for electric guitars can be divided into two groups, vibrato and non-vibrato
7.
Ruler
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A ruler, sometimes called a rule or line gauge, is an instrument used in geometry, technical drawing, printing, engineering and building to measure distances or to rule straight lines. The ruler is a straightedge which may also contain calibrated lines to measure distances, rulers have long been made from different materials and in a wide range of sizes. Plastics have also used since they were invented, they can be molded with length markings instead of being scribed. Metal is used for more durable rulers for use in the workshop,12 inches or 30 cm in length is useful for a ruler to be kept on a desk to help in drawing. Shorter rulers are convenient for keeping in a pocket, longer rulers, e. g.18 inches are necessary in some cases. Rigid wooden or plastic yardsticks,1 yard long, and meter sticks,1 meter long, are also used, classically, long measuring rods were used for larger projects, now superseded by tape measure or laser rangefinders. Desk rulers are used for three purposes, to measure, to aid in drawing straight lines and as a straight guide for cutting and scoring with a blade. Practical rulers have distance markings along their edges, a line gauge is a type of ruler used in the printing industry. These may be made from a variety of materials, typically metal or clear plastic, units of measurement on a basic line gauge usually include inches, agate, picas, and points. More detailed line gauges may contain sample widths of lines, samples of common type in several point sizes, measuring instruments similar in function to rulers are made portable by folding or retracting into a coil when not in use. When extended for use, they are straight, like a ruler, the illustrations on this page show a 2-meter carpenters rule, which folds down to a length of 24 cm to easily fit in a pocket, and a 5-meter-long tape, which retracts into a small housing. A flexible length measuring instrument which is not necessarily straight in use is the tailors fabric tape measure and it is used to measure around a solid body, e. g. a persons waist measurement, as well as linear measurement, e. g. inside leg. It is rolled up when not in use, taking up little space, a contraction rule is made having larger divisions than standard measures to allow for shrinkage of a metal casting. They may also be known as a shrinkage or shrink rule, a ruler software program can be used to measure pixels on a computer screen or mobile phone. These programs are known as screen rulers. In geometry, a ruler without any marks on it may be used only for drawing lines between points. A straightedge is used to help draw accurate graphs and tables. A ruler and compass construction refers to using an unmarked ruler
8.
Astronomy
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Astronomy is a natural science that studies celestial objects and phenomena. It applies mathematics, physics, and chemistry, in an effort to explain the origin of those objects and phenomena and their evolution. Objects of interest include planets, moons, stars, galaxies, and comets, while the phenomena include supernovae explosions, gamma ray bursts, more generally, all astronomical phenomena that originate outside Earths atmosphere are within the purview of astronomy. A related but distinct subject, physical cosmology, is concerned with the study of the Universe as a whole, Astronomy is the oldest of the natural sciences. The early civilizations in recorded history, such as the Babylonians, Greeks, Indians, Egyptians, Nubians, Iranians, Chinese, during the 20th century, the field of professional astronomy split into observational and theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects, theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. The two fields complement each other, with theoretical astronomy seeking to explain the results and observations being used to confirm theoretical results. Astronomy is one of the few sciences where amateurs can play an active role, especially in the discovery. Amateur astronomers have made and contributed to many important astronomical discoveries, Astronomy means law of the stars. Astronomy should not be confused with astrology, the system which claims that human affairs are correlated with the positions of celestial objects. Although the two share a common origin, they are now entirely distinct. Generally, either the term astronomy or astrophysics may be used to refer to this subject, however, since most modern astronomical research deals with subjects related to physics, modern astronomy could actually be called astrophysics. Few fields, such as astrometry, are purely astronomy rather than also astrophysics, some titles of the leading scientific journals in this field includeThe Astronomical Journal, The Astrophysical Journal and Astronomy and Astrophysics. In early times, astronomy only comprised the observation and predictions of the motions of objects visible to the naked eye, in some locations, early cultures assembled massive artifacts that possibly had some astronomical purpose. Before tools such as the telescope were invented, early study of the stars was conducted using the naked eye, most of early astronomy actually consisted of mapping the positions of the stars and planets, a science now referred to as astrometry. From these observations, early ideas about the motions of the planets were formed, and the nature of the Sun, Moon, the Earth was believed to be the center of the Universe with the Sun, the Moon and the stars rotating around it. This is known as the model of the Universe, or the Ptolemaic system. The Babylonians discovered that lunar eclipses recurred in a cycle known as a saros
9.
Course (music)
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A course, on a stringed musical instrument, is two or more adjacent strings that are closely spaced relative to the other strings, and typically played as a single string. The strings in each course are tuned in unison or an octave. Course may also refer to a single string normally played on its own on an instrument with other multi-string courses, an instrument with at least one course is referred to as coursed, while one whose strings are all played individually is uncoursed. Eventually, however, they came to be employed to alter the characteristics of instruments as well. A typical piano, for example, contains courses with one, all members of the mandolin family, except some versions of the lowest-pitched, have courses each of two or three strings, most commonly eight strings in four courses. The exception is some varieties of mando-bass, which have four individual strings, the baroque guitar has five courses, with the bottom four always double strung, and the top string either double or single. There are also several patterns of modern ten-string guitar but all have ten single strings, the twelve-string guitar has twelve strings, in six courses. The lowest three courses are tuned at octaves, with the primary string uppermost and the octave below it. The G course is either unison or at octaves, on some electric twelve-string guitars, and most notably the Rickenbacker 360/12, the octave strings are below the primary strings. The national instrument of Columbia, the tiple Colombiano, has four courses of three strings each and its higher-pitched relative, the tiple requinto, is similarly triple-strung. The American tiple, a smaller instrument loosely derived from the Columbian tiple, the electric twelve-string bass has twelve strings in four triple courses. Basses have also built with six double courses and other configs
10.
Mathematics
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Mathematics is the study of topics such as quantity, structure, space, and change. There is a range of views among mathematicians and philosophers as to the exact scope, Mathematicians seek out patterns and use them to formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proof, when mathematical structures are good models of real phenomena, then mathematical reasoning can provide insight or predictions about nature. Through the use of abstraction and logic, mathematics developed from counting, calculation, measurement, practical mathematics has been a human activity from as far back as written records exist. The research required to solve mathematical problems can take years or even centuries of sustained inquiry, rigorous arguments first appeared in Greek mathematics, most notably in Euclids Elements. Galileo Galilei said, The universe cannot be read until we have learned the language and it is written in mathematical language, and the letters are triangles, circles and other geometrical figures, without which means it is humanly impossible to comprehend a single word. Without these, one is wandering about in a dark labyrinth, carl Friedrich Gauss referred to mathematics as the Queen of the Sciences. Benjamin Peirce called mathematics the science that draws necessary conclusions, David Hilbert said of mathematics, We are not speaking here of arbitrariness in any sense. Mathematics is not like a game whose tasks are determined by arbitrarily stipulated rules, rather, it is a conceptual system possessing internal necessity that can only be so and by no means otherwise. Albert Einstein stated that as far as the laws of mathematics refer to reality, they are not certain, Mathematics is essential in many fields, including natural science, engineering, medicine, finance and the social sciences. Applied mathematics has led to entirely new mathematical disciplines, such as statistics, Mathematicians also engage in pure mathematics, or mathematics for its own sake, without having any application in mind. There is no clear line separating pure and applied mathematics, the history of mathematics can be seen as an ever-increasing series of abstractions. The earliest uses of mathematics were in trading, land measurement, painting and weaving patterns, in Babylonian mathematics elementary arithmetic first appears in the archaeological record. Numeracy pre-dated writing and numeral systems have many and diverse. Between 600 and 300 BC the Ancient Greeks began a study of mathematics in its own right with Greek mathematics. Mathematics has since been extended, and there has been a fruitful interaction between mathematics and science, to the benefit of both. Mathematical discoveries continue to be made today, the overwhelming majority of works in this ocean contain new mathematical theorems and their proofs. The word máthēma is derived from μανθάνω, while the modern Greek equivalent is μαθαίνω, in Greece, the word for mathematics came to have the narrower and more technical meaning mathematical study even in Classical times
11.
Mandolin
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A mandolin is a musical instrument in the lute family and is usually plucked with a plectrum or pick. It commonly has four courses of doubled metal strings tuned in unison, although five, the courses are normally tuned in a succession of perfect fifths. It is the member of a family that includes the mandola, octave mandolin, mandocello. There are many styles of mandolin, but three are common, the Neapolitan or round-backed mandolin, the mandolin and the flat-backed mandolin. The round-back has a bottom, constructed of strips of wood. The carved-top or arch-top mandolin has a shallower, arched back. The flat-backed mandolin uses thin sheets of wood for the body, each style of instrument has its own sound quality and is associated with particular forms of music. Neapolitan mandolins feature prominently in European classical music and traditional music, carved-top instruments are common in American folk music and bluegrass music. Flat-backed instruments are used in Irish, British and Brazilian folk music. Some modern Brazilian instruments feature a fifth course tuned a fifth lower than the standard fourth course. There has also been a type and an instrument with sixteen-strings. Much of mandolin development revolved around the soundboard, pre-mandolin instruments were quiet instruments, strung with as many as six courses of gut strings, and were plucked with the fingers or with a quill. However, modern instruments are louder—using four courses of metal strings, the modern soundboard is designed to withstand the pressure of metal strings that would break earlier instruments. The soundboard comes in many shapes—but generally round or teardrop-shaped, sometimes with scrolls or other projections, there is usually one or more sound holes in the soundboard, either round, oval, or shaped like a calligraphic f. A round or oval sound hole may be covered or bordered with decorative rosettes or purfling, Mandolins evolved from the lute family in Italy during the 17th and 18th centuries, and the deep bowled mandolin, produced particularly in Naples, became common in the 19th century. Dating to around c.13,000 BC, a painting in the Trois Frères cave in France depicts what some believe is a musical bow. From the musical bow, families of stringed instruments developed, since each string played a note, adding strings added new notes, creating bow harps, harps. In turn, this led to being able to play dyads and chords, another innovation occurred when the bow harp was straightened out and a bridge used to lift the strings off the stick-neck, creating the lute
12.
Harry Partch
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Harry Partch was an American composer, music theorist, and creator of musical instruments. He composed using scales of unequal intervals in just intonation, and was one of the first 20th-century composers in the West to work systematically with microtonal scales. He built custom-made instruments in these tunings on which to play his compositions, to play his music, Partch built a large number of unique instruments, with such names as the Chromelodeon, the Quadrangularis Reversum, and the Zymo-Xyl. Partch described his music as corporeal, and distinguished it from abstract music, ancient Greek theatre and Japanese Noh and kabuki heavily influenced his music theatre. Encouraged by his mother, Partch learned several instruments at a young age, by fourteen, he was composing, and in particular took to setting dramatic situations. He dropped out of the University of Southern Californias School of Music in 1922 over dissatisfaction with the quality of his teachers, in 1930, he burned all his previous compositions in a rejection of the European concert tradition. Partch frequently moved around the US, early in his career, he was a transient worker, and sometimes a hobo, later he depended on grants, university appointments, and record sales to support himself. In 1970, supporters created the Harry Partch Foundation to administer Partchs music, Partch was born on June 24,1901, in Oakland, California. His parents were Virgil Franklin Partch and Jennie, the Presbyterian couple were missionaries, and served in China from 1888 to 1893, and again from 1895 to 1900, when they fled the Boxer Rebellion. Partch moved with his family to Arizona for his mothers health and his father worked for the Immigration Service there, and they settled in the small town of Benson. It was still the Wild West there in the twentieth century. Nearby, there were native Yaqui people, whose music he heard and his mother sang to him in Mandarin Chinese, and he heard and sang songs in Spanish and the Yaqui language. His mother encouraged her children to music, and he learned the mandolin, violin, piano, reed organ. His mother taught him to read music, the family moved to Albuquerque, New Mexico, in 1913, where Partch seriously studied the piano. He had work playing keyboards for silent films while he was in high school, by 14, he was composing for the piano. He early found an interest in writing music for dramatic situations, and often cited the lost composition Death, Partch graduated from high school in 1919. The family moved to Los Angeles in 1919 following the death of Partchs father, there, his mother was killed in a trolley accident in 1920. He enrolled in the University of Southern Californias School of Music in 1920 and he moved to San Francisco and studied books on music in the libraries there and continued to compose
Play (help·info). Half of this length will produce a pitch two octaves higher than the original—four times the initial frequency (4:1)—and so on. Standard diatonic Pythagorean tuning (Ptolemy's Diatonic Ditonic) is easily derived starting from superparticular ratios, (n+1)/n, constructed from the first four counting numbers, the tetractys, measured out on a monochord.[citation needed] The mathematics involved include the multiplication table, least common multiples, and prime and composite numbers.[4]
"Monochord". Encyclopædia Britannica. 18 (11th ed.). 1911.
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