Magnetic Compass

10 Key excerpts on "Magnetic Compass"

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  Encyclopedia of the Scientific Revolution

  From Copernicus to Newton

  • Wilbur Applebaum(Author)
  • 2003(Publication Date)
  • Routledge

    (Publisher)

  Compass, Magnetic It played three walk-on parts in the Scientific Revolution. First, it was a major symbol of the “battle of the ancients and the moderns,” a battle conclusively won for the moderns by late-seventeenth-century science. Second, it was the main piece of apparatus used in navigation, a vital field of study that fruitfully united the “hand knowledge” of navigators with the “head knowledge” of philosophers into recognizably experimental science. Third, throughout the Scientific Revolution, the compass was believed to offer a solution to the problem of finding longitude at sea, the scientific-cum-technical problem that arguably received more state encouragement than any other in the seventeenth century. A precondition of the Scientific Revolution was belief in a concept of progress. As late-Renaissance humanists sought proofs of the superiority, or at least equality, of their age with classical antiquity, they always cited the Magnetic Compass. Although ancient Greeks knew of the magnet’s attractive power, they did not discover its directional property, unlike the Chinese, who developed the first north-seeking devices. As knowledge of them penetrated late-medieval Europe, development of the nautical compass made possible transoceanic voyages such as Columbus’s to America in 1492. Jean Bodin could write in 1560 of the compass (as well as of printing and gunpowder—also Chinese inventions) as proof of progress in technology. “What, for example, is there more marvellous.” Francis Bacon (1561–1626) famously extended the argument for progress in technology to science in Aphorism 129 of his New Organon : “printing, gunpowder and the compass...have changed the appearance and state of the whole world.” For Bacon, the sciences should progress like the arts and for the same reason: that the philosopher, like the navigator, should pay attention to useful things, not Scholastic words

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  Renaissance Responses to Technological Change

  • Sheila J. Nayar(Author)
  • 2018(Publication Date)
  • Palgrave Macmillan

    (Publisher)

  In a sense, what we are dealing with is an epistemological mouvance 31 —which is to say, variations, modifications, and eventually the wholesale evacuation of discrete collective knowledges tied to place, the latter having been necessary in order for geographical science to emerge. But before addressing the cosmographically large and cartographically locomotive, let us attend first to literature’s more explicit engagement with that tiniest of instruments responsible for ushering in not only the plying of grand seas and revisioning of the world, but a King’s declaration that nothing in the world was unless it appeared on a map. The Material-Metaphysical Pull of the Magnetic Compass Pliny the Elder (d. 79 c. e.) contends in Natural History that magnetism was discovered by a Greek shepherd, Magnes, when the iron nails of his boots and metal tip of his crook exhibited attraction to a particular rock. 32 How it worked or why, nobody knew—and still did not know some 1100 years later, when that magnetic power was lodged in a European compass. 33 Its needle “points towards the Stella Maris [Star of the Sea],” declared Aquinas’ colleague Thomas of Cantimpré in 1240, and from that northern position “it does not move.” 34 (When later antiquarian William Camden would dub naval glory’s restorer, Queen Elizabeth, both the North Star and Queen of the Sea, 35 he did so associatively to drive home that she, like the Virgin Mary before her, was a star whose fixity was able to guide sailors.) While Polydore Vergil likewise applauded the anonymous ingenuity that had gone into fashioning “that little box that sailors use so skillfully to guide their sailing,” 36 part of that skill entailed knowing how to deal with the innumerable inconstancies produced by faulty or weakened compasses and, even more mysteriously, by their place of manufacture

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  The Pull of History

  Human Understanding of Magnetism and Gravity through the Ages

  • Yoshitaka Yamamoto(Author)
  • 2017(Publication Date)
  • WSPC

    (Publisher)

  More than this, it is likely that he introduced the magnetic island and the magnetic mountain in an attempt to explain what was already understood about magnetic directionality. The same line of thinking was expressed in other quarters in the sixteenth century, for example (according to Gilbert) by Girolamo Fracastoro, an Italian physician; and by Francesco Maurolico, a mathematician, astronomer, and refugee from the Byzantine Empire, who went so far as to claim that the point on Earth with which magnets aligned themselves was none other than Olaus Magnus’s magnetic mountain itself. 23 In direct contradiction of Peregrinus’s and Roger Bacon’s thirteenth-century view that it is from the poles of the heavens that the poles of the magnet receive their virtue, as well as of Ficino’s claim in the fifteenth century that magnets acquire their power from the constellation Ursa Minor, the emerging facts strongly suggested that what attracted magnets was a point on the Earth itself. This represented a radical shift in the interpretation of magnetic force, which in turn led to a new understanding of the Earth and paved the way not only for the realization that the Earth itself is what influences magnets and magnetic needles but also for Gilbert’s discovery that the Earth itself is a huge magnet. Section 2—The Magnetic Compass: Discovering the World As discussed earlier, little is known about the way in which compasses first came into use by European sea voyagers beyond the fact that this transition took place sometime before the end of the twelfth century. But determining the timing of the compass’s introduction is far less important to science history than investigating the consequences of its invention. The Magnetic Compass—or, more accurately, the compass-equipped caravel, a type of sailing ship highly suited to ocean travel—is among the triad of technologies that demarcate medieval from modern times in Europe, the other two being gunpowder and mechanical printing

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  The Grand Titration

  Science and Society in East and West

  • Joseph Needham(Author)
  • 2013(Publication Date)
  • Routledge

    (Publisher)

  21 were a very important part of the preparation for Newton through Gilbert and Kepler. The field physics of still later times, established in Clerk Maxwell’s classical equations, and more congruent with organic thought than Greek atomic materialism, can again be traced back to the same root. Hence the concluding words, entirely justified, of the passage quoted above on p. 64.

  Mutatis mutandis one can make the same two statements about the Magnetic Compass as were made about gunpowder. It was not a purely empirical or technological achievement because the Taoist geomancers had their theories during its long developmental period, as we know well from many texts that have been preserved. The fact that these theories were not of the modern type does not entitle us to ignore them. The whole discovery had arisen from a divination procedure or cosmical magic, but what carried it forward was the Chinese attachment to a doctrine of action at a distance, or wave-motion through a continuum, rather than direct mechanical impulsion of particles; atomism being foreign to them, this it was which led them on to see nothing impossible in the pole-pointing property of a stone or of iron which had touched it. Secondly, the Magnetic Compass, or more broadly speaking, the knowledge of magnetic polarity as well as magnetic attraction, had also its sociologically earth-shaking character in the Western world. The part which it played in the nascent phases of modern science would be sufficient justification for this in itself, but there was more; for in the hands of the European sea-captains of the fifteenth century the compass crowned a whole period of navigational science which had been inaugurated in the thirteenth, and made possible not only the circumnavigation of the African, but the discovery of the American, continent. How profoundly this affected the life of Europe, with the influx of vast quantities of silver, the marketing of innumerable new kinds of commodities, and the opening up of colonies and plantations, hardly requires elaborate emphasis here, when even elementary textbooks tell the story. But again there is the other side of the picture. Chinese society was not upset by the knowledge of magnetic phenomena; the geomancers continued to advise families upon the best siting of houses and tombs with ever-increasing refinement of their baseless art,22 and the sea-captains continued to find their way to the East Indies or the Persian Gulf in a trade that was peripheral to China’s main economic life.23

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  The Lost Art of Finding Our Way

  • John Edward Huth(Author)
  • 2013(Publication Date)
  • Belknap Press

    (Publisher)

  Many of the navigation folios from this era had tables for each port that gave the time of high tide relative to the position of the Moon. This kind of information would be criti-cal for a Mediterranean navigator making his way to a port on the North Sea. Compass Principles The Chinese and Greeks knew about magnetism circa 500 BC. The name is derived from a stone called magnetite, which was found in the region of Magnesia in Thessaly. Magnetite could be fashioned into lodestones that displayed a mysterious attraction to each other and to iron. When an iron bar was drawn across a lode-stone, it acquired magnetic properties. Although well known, the magnetic properties of iron, nickel, and magnetite were not used in practical applications for centuries. A compass magnet is called a dipole (Figure 37), meaning that it has two poles: north and south. This is more commonly called Maps and Compasses 109 a bar magnet. By convention if we take a dipole and let it swivel freely in the horizontal plane, then let it settle, the north end aligns in the direction of the northbound magnetic lines of the Earth. We draw magnetic fields as continuous lines beginning on the north pole of the magnet and ending on the south pole. The arrows in Figure 37 indicate the southbound direction of the field lines. Magnetic poles of the same kind (north-north and south-south) will repel each other and unlike poles (north-south) will attract each other; that is to say, a north pole will repel a north pole, while a north pole will attract a south pole. If a magnetic dipole is put in a uniform magnetic field, it will experience a torque (Figure 38) that causes an object to rotate. A playground seesaw is a good example of torque in action. The seesaw rotates about a fixed point, and the weight of the children on each end exerts a force at some distance from the point of rota-tion. In making a compass we put a pivot point in the middle of the magnet that allows it to rotate freely.

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  Geographies of Disorientation

  • Marcella Schmidt di Friedberg(Author)
  • 2017(Publication Date)
  • Taylor & Francis

    (Publisher)

  Wujing Zongyao ), dated 1044.

  Pointing north or south, as we have seen, the Magnetic Compass continues to be a valuable and simple instrument for orienting people and things in space for a variety of purposes (Lane, 1963).5 Its functioning, today enhanced by new technologies, is based on the ability of a needle to align itself with the Earth’s magnetic field, compensating for any deviations. In China, the writings of Gui Guzi and Han Fei (280–233 BC ) attest an ancient tradition of studying the orientation of magnetic stones towards the poles. In Europe, the use of the magnetic needle for navigating in bad weather conditions was probably introduced by the Arabs (De Saussure, 1923). The first written mention of it appears in Guyot de Provins (1190), who lamented the fact that the Pope did not fulfil the same role for Christians as the compass needle for sailors; we owe further allusions to the compass to the bishop Jacques de Vitry (1204) and to Brunetto Latini who referred to it as an instrument of long-established use. The analogy between the compass needle and religious or moral teaching recurs in many old literary sources, from the Augustinian monk Alexander Neckham, to Guido Guinizelli, to Dante: “Si mosse voce, che l’ago a la stella parer mi fece in volgermi al suo dove” (Dante, Paradiso, Canto XII, 29–30).6 The forerunner of modern experimental science in the field of magnetism was Pierre Pelerin de Maricourt, author of the Epistola de magnete (1269). The Epistola was later followed by the treatise De magnete (1600) by William Gilbert, physician to Elizabeth I and the first to introduce the notion of the earth as a huge magnet (Du Trémolet de Lacheisserie et al., 2003). The study of terrestrial magnetism gained new theories and instruments thanks to the work of Carl Friedrich Gauss and Wilhelm Weber. In 1834, with the assistance of Alexander von Humboldt and his numerous international contacts – from the British Royal Society to the tsar of Russia – Gauss and Weber founded the Göttinger Magnetischer Verein

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  Geomagnetism, Aeronomy and Space Weather

  A Journey from the Earth's Core to the Sun

  • Mioara Mandea, Monika Korte, Andrew Yau, Eduard Petrovsky(Authors)
  • 2019(Publication Date)
  • Cambridge University Press

    (Publisher)

  PART I Introduction 1 Objectives of Geomagnetic and Aeronomy Studies David Kerridge Magnetism was discovered in antiquity as the remarkable ability of a type of black rock, lodestone, to attract iron and to both attract and repel other lumps of lodestone. This was followed by the discovery that, when free to rotate, a piece of lodestone turns and aligns itself in a particular direction. The Earth’s magnetic field entered human service when this directive property was made useful through the invention of the compass around a thousand years ago, most probably in China. There is evidence that the Chinese also found that the compass direction deviated from true north–south and so discovered what today is termed magnetic declination, the angle between true and magnetic north (Needham, 1962). The compass, as a navigational tool, later became invalu- able to mariners in their voyages of exploration and trade (Jonkers et al., 2003). (It is interesting to note the geomag- netic field is now used as a directional reference in high- accuracy drilling for production of hydrocarbons and that many of today’s ubiquitous smartphones have in-built mag- netic sensors and global geomagnetic field models, putting magnetic navigational capability into the hands of people worldwide.) The invention of the compass was a technological achievement, and the properties of lodestone stimulated curiosity and the beginning of scientific investigation, nota- bly by Petrus Peregrinus, who introduced the concept of magnetic poles in his letter of 1269. William Gilbert (1600) acknowledged Peregrinus’ influence when he published the results of years of careful investigation into the properties of a spherical lodestone in his book De Magnete. Gilbert vig- orously advocated discovery through meticulous experi- mentation and measurement, and De Magnete is often cited as the first scientific textbook.

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  Sensors for Mobile Robots

  • H.R. Everett(Author)
  • 1995(Publication Date)
  • A K Peters/CRC Press

    (Publisher)

  Such geomagnetic sensors, for purposes of this discussion, will be broken down into the following general categories: • Mechanical Magnetic Compasses. • Hall-effect compasses. • Fluxgate compasses. • Magnetoresistive compasses. • Magnetoinductive compasses. • Magnetoelastic compasses. 328 Sensors for Mobile Robots 12.1 Mechanical Magnetic Compasses The first recorded use of a Magnetic Compass was in 2634 BC, when the Chinese suspended a piece of naturally occurring magnetite from a silk thread and used it to guide a chariot over land (Carter, 1966). Much controversy surrounds the debate over whether the Chinese or the Europeans first adapted the compass for marine applications, but by the middle of the 13th century such usage was fairly widespread around the globe. William Gilbert (1600) was the first to propose that the earth itself was the source of the mysterious magnetic field that provided such a stable navigational reference for ships at sea. The early marine compasses were little more than magnetized needles floated in water on small pieces of cork. These primitive devices evolved over the years into the reliable and time proven systems in use today, which consist of a ring magnet or pair of bar magnets attached to a graduated mica readout disk. The magnet and disk assembly floats in a mixture of water and alcohol or glycerin, such that it is free to rotate around a jeweled pivot. The fluid acts to both support the weight of the rotating assembly and to dampen its movement under rough conditions. The sealed vessel containing the compass disk and damping fluid is typically suspended from a two-degree-of-freedom gimbal to decouple it from the ship’s motion. This gimbal assembly is mounted in turn atop a floor stand or binnacle. Situated on either side of the binnacle are massive iron spheres that, along with adjustable permanent magnets in the base, are used to compensate the compass for surrounding magnetic anomalies that alter the geomagnetic lines of flux.

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  WLAN Positioning Systems

  Principles and Applications in Location-Based Services

  • Azadeh Kushki, Konstantinos N. Plataniotis, Anastasios N. Venetsanopoulos(Authors)
  • 2012(Publication Date)
  • Cambridge University Press

    (Publisher)

  As such, this device can be used to determine the heading or direction of vessels. Figure 1.2 shows an example of a modern compass. Though the origins of the compass date back several thousand years, the first reference to the use of this device for navigation is found in the twelfth century [74]. Figure 1.2. Example of a modern compass. Image © iStockphoto.com/Ldf. 6 Positioning through the ages 1.3 The age of exploration As time passed, the aforementioned techniques were perfected to allow for long-distance travel both by land and sea. For example, the Middle Ages saw significant advancement in the science of navigation by Islamic and Persian scholars who improved measurement techniques used in celestial navigation and created detailed maps of the known world. For example, Islamic navigators invented the kamal, an instrument used for measuring the angle between the horizon and a navigational star and further improved existing navigational instruments such as the astrolabe. Figure 1.3 shows a photograph of a Persian astrolabe from the thirteenth century. The scholars of this period also contributed significantly to the development of cartography (map making) and geographical sciences. Given this backdrop, the Age of Exploration began in the fifteenth century when European ships set out to conquer and explore new lands. It was during the Age of Exploration that Portuguese and Spanish explorers including Christopher Columbus (fifteenth century), provided accounts from distant lands that led to the interaction of Figure 1.3. A Persian astrolabe from the thirteenth century. “Astrolabe,” Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/wiki/Astrolabe. 1.3 The age of exploration 7 Figure 1.4. A German astrolabe from the sixteenth century. “Astrolabe,” Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/wiki/Astrolabe.

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  Treatise on Geophysics, Volume 5

  Geomagnetism

  • Masaru Kono(Author)
  • 2010(Publication Date)
  • Elsevier

    (Publisher)

  The dry pivoted compass was described in Shih Lin Kuang Chi (Guide through the Forest of Affairs), an encyclopedia compiled around 1150 by Chhen Yuan-Ching . In this compass, an woo-den turtle has a tail made of a magnetic needle. A thin bamboo stick stands from the baseboard and holds the turtle at the hole made in its belly. The turtle rotates and points to the north because of the magnetic needle ( Figure 3 ). 1.1.3 Magnetic Compass in European Documents It is not clear when the knowledge of the Magnetic Compass reached Europe, and when it was first used in navigation. Gilbert wrote that it was brought to Europe by the Venetian Marco Polo, but there is evidence that the compass was used well before his return to Europe in 1295. It is often thought that the knowledge of the compass came from China through the intermediary of the Islam civilization. There is no written evidence, however, and the appearance of the compass is earlier in European documents than in Islamic ones (Mitchell, 1932; Needham, 1962). The earliest record of the north–south-seeking property of the compass in Europe appears to be that of Alexander Neckham (1157–1217) of St. Albans, England. In two treatises, De Utensibibus and De Naturis Rerum written about 1190, he described the use of the magnetic needle in naviga-tion to indicate north, and that the needle is put on a pivot which may be the form of a primitive compass (Mitchell, 1932). Guyot de Provins of France (1184– 1210) wrote a poem called La Bible around 1205, in which he described a floating compass. Jacques de Vitory of Kingdom of Jerusalem (1165–1240) left a similar document ( c . 1218). These people were all monks or priests, and they only referred to the com-pass as having the noble property (to point always to the same direction). It is therefore natural to think that the properties of the compass were known to mariners well before it became popular so that the priests could use it for allegory in these writings (Mitchell, 1932).

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