电和机械能量的转变.doc

Chapter 19 TRANSFORMATIONS OF ELECTRICAL AND MECHANICAL ENERGY 電和機械能量的轉變 Michael Faraday (1791-1867) 麥克法拉第 Michael Faraday (1791-1 867) (Figure 19.1) was a great experimentalist and a practical theoretician ; he made an extraordinary number of very important contributions to electricity and magnetism. In 1820 Qersted demonstrated that electric current produced magnetism. In 1821 Faraday was the first to demonstrate the principles involved in transforming electrical energy into mechanical energy. He was also the first to demonstrate ,in 1831, that magnetism and motion could generate electricity. These two discoveries became the basis for building electric motors and generators. In addition to his extensive experiments with electricity and magnetism, Faraday also studied and experimented with chemistry, electrochemistry, optics, and light, making fundamental discoveries in each.麥克法拉第 (1791-1 867) (圖19.1) 是個偉大的實現家和實際的理論家； 他在電和磁的貢獻上令人稱奇。在1820年奧斯特證明電流的磁效應。在1821年法拉第最先證明把電能轉變成機械能的原理。他也最先在1831年證明，磁性和運動能產生電。這兩項發現成為建造電動機和發電機的基礎。除他的廣大的用電和磁性作的實驗之外， 法拉第也研究並且做了化學，電化學，光學和光的實驗，並在裡頭取得基本的發現。 Figure19.1 Portrait of Michael Faraday from his Lectures on the Various Forces of Matter,1863. Faraday was born near London in 1791. His father was a blacksmith who had moved that year from Yorkshire seeking work. The fathers health was not good, and he earned barely enough to sustain his family. Later, Faraday said that one week when he was young he had only water and one loaf of bread to eat. Notwithstanding the many difficulties the Faradays faced, it was a close-knit, loving, caring family. In later years, Michael helped his older brother, Robert, in his work as a gas fitter, and was responsible for the education of his younger sister, Margaret.法拉第在1791年在倫敦附近出生。那年他的父親是從約克郡來此謀職的一名鐵匠。父親的健康不好， 並且他賺得錢僅足夠維持他的家庭。後來，法拉第說小時候窮到有一個禮拜只喝水和一條麵包來度日。雖然法拉第一家人面臨很多困難，一家人的感情更為親密。在更晚的年， 麥克幫助他的哥哥，羅伯特，他是一名瓦斯設備安裝工，並且對他的妹妹，麥格麗特的教育負責。 From early years, religion was an important influence in Faradays life. His family belonged to the Sandemanians, a demanding Protestant sect that believed in the literal interpretation of the Bible. It emphasized love of fellow man, a sense of community, a sense of unity in all physical things, humility, and human fallibility. Throughout his life, Faraday believed that nature possessed an inner coherence and simplicity.從早年以來，宗教是法拉第的生活中重要的影響。他的家庭屬於山地門教徒，山地門教是一個要求信徒相信聖經的文字解釋的新教徒教派。它強調愛人類，一個社區的感覺，一個在全部自然界的事情裡，謙遜，以及人為錯誤的感覺。在整個他的生活期間，法拉第相信自然擁有內部連貫性和簡單。 Faradays few years in a common day school taught him only the rudiments of reading, writing, and arithmetic. At age 13, in 1804, Faraday began working as an errand boy for G. Riebau , who had been born in France, and had moved to London to escape the turmoil of the French Revolution. Riebau had a shop near Faradays home and sold newspapers and books, and rebound old books. A year later, Faraday was apprenticed to Riebau for seven years, to learn bookbinding. During these years, Faraday developed manual skills which helped him later doing his experimental work.法拉第上過幾年只有教他讀，寫，以及算術基礎的普通學校。在13歲的時候，即1804年，法拉第開始為喬治.雷伯做個當差者的工作。雷伯，在法國出生，並且搬到倫敦來逃離法國革命的騷動。雷伯的商店接近法拉第家出售報紙和書，並且重新裝訂舊的書。一年後，法拉第被送去當雷伯的徒弟7 年，學習裝訂術。在這些年，法拉第發達的手工技能幫助他日後的實驗工作。 Being exposed to books was a great benefit to Faraday, and he took advantage of the opportunity to read and to learn. He was greatly impressed by The Improvement of the Mind, written in the eighteenth century by Dr. Isaac Wafts, a clergyman and a writer of hymns. It helped Faraday organize his thoughts and ideas, and made many suggestions for self-improvement. Waftss important suggestions were keeping a notebook to record ideas and interesting observations, and to correspond with friends to learn to articulate ideas. Faraday had been attending lectures, and began to take notes as Watts recommended. In addition to his suggestions, Wafts expressed a philosophy of avoiding false theories and intellectual delusions. He wrote that when approaching a problem, observe facts carefully and thoroughly; in describing results, use precise language. This will protect the writer from premature generalizations.接觸於書本對法拉第有很大的好處， 並且他利用機會讀並且學習。他對撒華茲博士在18 世紀所寫的 心的改進 印象非常深刻。撒華茲是一位牧師和一位讚美詩的作家。它幫助法拉第組織他的思想，並且提出很多自我改進的建議。華茲的重要建議是用一本筆記本記錄想法和有趣的觀察，並且符合朋友學習清楚地說想法。法拉第聽演講，並且在華茲的建議，開始記筆記。除他的建議之外，華茲表示避免錯誤理論和知性錯覺的哲學。他寫到當處理一個問題時，仔細和徹底地觀察事實； 在描述結果方面，使用準確的語言。這將保護作家以防過早的概括。 Faraday became interested in science as he was rebinding an Encyclopaedia Britannica, which contained an article on electricity by James Tytler. Tytler explanation of electricity was at variance with the beliefs held by most scientists. He did not believe in the two-fluid theory which was popular in Europe, nor in Franklins one-fluid theory. For him, electricity was a vibration rather than a flow of material particles, and he used his hypotheses to explain the results he observed. He presented his ideas in a challenging fashion, giving Faraday a good example of questioning others beliefs in science. Faraday checked some of Tytlers facts by building an electrostatic generator with a discarded glass bottle and some scraps of wood. He also made a Leyden jar.法拉第對科學感興趣，當他正重新裝訂大英百科全書裡關於詹姆士泰特勒對於電的文章。泰特勒對電的解釋與大多數科學家秉持的看法不一致。他沒相信在歐洲受歡迎的兩流體理論，也不相信法蘭克林的流體說。對他來說，電是一次振動而不是物質粒子的流動， 並且他使用他的假說解釋他觀察的結果。他用富於挑戰性模式提出他的想法，給法拉第一個在科學方面質疑其他看法的好例子。法拉第透過用一個丟掉的玻璃瓶子和木頭的碎片建造一台靜電的發電機檢查泰特勒的一些事實。他也製造萊頓瓶。 In 1808 James Tatum and several friends formed the City Philosophical Society which met Wednesday evenings at Tatums home to hear lectures given by Tatum and other members of the group, to discuss scientific topics, and to use Taturms library. In 1810 Faraday attended meetings of the group, and this began his basic education of the sciences. His brother, Robert, who was working as a blacksmith at the time, paid the shilling fee to each of the lectures.在1808年詹姆士塔特姆和幾位朋友組成星期三晚上在塔特姆家來聽塔特姆和其他團體成員的演講，討論科學題目，並且使用塔特姆的圖書館的城市哲學的社會。在1810年法拉第參加團體的會議，這開始他的科學的基礎教育。他的哥哥羅伯特那時正做一名鐵匠，把費用支付到每次演講裡。 Benjamin Abbott was a fellow member of the City Philosophical Society. He was a year and a half younger than Faraday, had attended good schools, and was well educated. Faraday admired him very much, and the two exchanged lengthy letters in 1812 and 1813. Abbott, recognizing Faradays abilities and promise, kept each of his letters. These are the major records of Faradays thinking about science and experimenting in those early years. 班傑明阿博特是一個城市哲學社會的成員。他比法拉第年輕一年半，已經上好學校，並且被教育得很好。法拉第非常欽佩他，以及在1812 和1813年的兩封交換的冗長的信。阿博特，承認法拉第的能力和承諾，並保存他的每封信。這些主要記錄的是法拉第科學和那些早年做實驗的想法。 Faraday first saw a Voltaic pile at a meeting of the City Philosophical Society, and decided to build one himself He used seven pairs of plates; the zinc ones were made from rolled malleable metal to be thin, and he cut them into disks about one inch in diameter. He used halfpence coins for the copper plates. Between each pair of disks, Faraday put a disk of paper which had been soaked in a solution of muriate of soda (sodium chloride). Faraday used this pile to disassociate a solution of sulphate of magnesia. Later piles had larger plates, many more pairs, and used flannel cloth to hold the electrolyte.法拉第首先在城市哲學社會的會議看見一伏打電，並決定自己建造一個他使用7 個盤子； 鋅由有延伸性的金屬製成薄的， 並且把他們分割成大約直徑一英寸的圓面。 他把硬幣用於薄銅板。在每對磁片之間，法拉第放一個已經被蘇打(氯化鈉)的溶液裡浸泡的紙的磁片 .法拉第使用這堆分離硫酸氧化鎂的溶液。過後堆有更大的盤子，更多的對，並且使用法蘭絨布當電解物。 Faraday also read Conversations on Chemistry by Mrs. Jane Marcet, the wife of a Swiss physician. The writings had been inspired by Humphry Davys popular lectures at the Royal Insitution in London. Davy stressed the importance of chemistry and tied together chemistry, electricity, optics, and thermodynamics in a grand scheme of science, which was captured by Mrs. Marcet. It directed Faradays attention to chemistry and established Davy in Faradays mind as a model of a person that Faraday would like to be.法拉第也有讀由瑪西夫人的作品 在化學上的談話 。法拉第被在倫敦皇家科學院受歡迎的德維爵士的演講所鼓舞。德維強調化學的重要性並且在一個科學的最重要的計畫裡結合化學，電，光學和熱力學，這些被德維所注意。法拉第也將注意到化學並且在法拉第的頭腦裡確定戴維是他想成為的楷模。 The Royal Institution had been founded in 1799 by an American, Benjamin Thompson, and others in Britain. Thompson had been given the title of Count Rumford by the King of Bavaria. The purpose of The Royal Institution was to teach by lectures and experiments the application of science to the common purpose of life. Humphry Davy was Professor of Chemistry at the institution.一名美國人班傑明湯普森和在英國的其它人已經在1799年建立皇家科學院的機構。湯普森被巴伐利亞的國王封為福德伯爵。皇家科學院的目的 透過演講和實驗教學生活的科學應用。德維在機構裡是化學的教授。 In 1812 one of Riebaus customers, Dance, who was a member of the Royal Institution, gave Faraday tickets to four lectures by Davy at the Royal Institution. Faraday was an eager listener and made careful notes. He recorded each of Davys scientific points and reported them to his colleagues at the City Philosophical Society.他記錄每個戴維的科學點並且在城市哲學的社會把他們報告給他的同事。法拉第是一位渴望的傾聽者並且作小心的筆記。在1812年雷伯的顧客之一的丹斯是學院裡的成員，他給了法拉第4張德維在學院裡演講的票。 In October 1812 Faradays apprenticeship came to an end. It was a sad event for him because the atmosphere in Riebaus shop was stimulating intellectually, and Ribeau was a kind and generous employer. Faraday also felt that bookbinding and trade were neither creative nor stimulating to him, and he was reluctant to devote his life to them. He was much more interested in chemistry and science. Having few options, however, he took a position with another bookbinder. Later that month Davy, now Sir Humphry Davy, had an accident handling chloride of nitrogen; it exploded and temporarily blinded him. Faraday was recommended to be his amanuensis, and he served him in that position for a short time.在1812年10月法拉第的徒工身分完結。對他來說是件悲傷的事，因為在雷伯的商店裡可以刺激智力，並且雷伯是那種慷慨的雇主。 法拉第也感到裝訂和貿易既沒有創造性也沒有刺激性， 並且他不願意獻身於他們。他對化學和科學更加感興趣。有很少選擇，不過，他對其他裝訂商採取一個態度。過了那月德維，現在的戴維伯爵先生，發生氮的氯化物處理意外； 它爆炸並且暫時弄瞎他。法拉第被推薦成為他的抄寫員， 並且他一段時間在那個位置接待他。 In December Faraday sent to Davy a carefully bound volume containing a transcription of the notes he had taken while attending the four lectures by Davy the year earlier, and asked for a position at the Royal Institution. Davy was very pleased with the notes, Faradays understanding of chemistry, and his thoughtfulness. He would have liked to hire Faraday, but at that time there was not a position available. Two months later, however, a laboratory assistant was discharged for brawling, and on March 1, 1813, Faraday replaced him. His salary was 25 shillings per week and two rooms at the top of the Institution, fuel, and candles supplied.在12月，法拉第仔細地裝訂好筆記的抄寫卷給德維，更早聽到德維的4次演講，並且在皇家學院要求一個位置。戴維對筆記，以及法拉第所理解化學和他的深思非常滿意。他可能喜歡僱佣法拉第，但是在那時沒有一個可提供的位置。兩個月以後，不過，一個實驗室助手吵著要離職，在1813年3月1日，法拉第取代他。 他薪水每周25先令和提供學院裡的二間房間，燃料和蠟燭。 In 1807 Davy had announced that he had isolated potassium by passing an electric current through slightly dampened potash, and sodium by passing a current through soda. The Institut de France recognized these accomplishments in 1813 by awarding Davy the medal and prize established by Napoleon for scientific achievements.在1807年德維已經宣佈他已經透過電流通過稍微弄濕的鉀鹼和透過讓一個電流通過蘇打的鈉分離鉀。學會達芬奇表彰德維在1813年的成就透過授予這枚由拿破崙所建立的科學成就獎的獎章和獎金。 In the autumn of 1813 Davy and Lady Davy departed for France to receive the medal and, in addition, planned an eighteen month tour of Europe. Faraday joined them as Davys secretary and valet. Even though England and France were at war at that time, Napoleon had given Davy permission to travel through France and Italy. In those two countries and in Switzerland and Germany, Davy met with distinguished scientists, discussing chemistry, physics, electricity, and philosophies. Faraday, the former bookbinders apprentice who had never been far from London, learned much and benefited greatly from these experiences.在1813年的秋天德維和德維女士前往法國去接受這枚獎章，另外計畫到歐洲旅行18 個月。法拉第與他們一起前行並當德維的秘書和侍僕。雖然英國和法國在那時發生戰爭，但拿破崙已經允許德維穿越法國和義大利。在那兩國瑞士和德國，德維與卓越的科學家見面，討論化學，物理學，電和哲學。 法拉第， 從未遠離倫敦的前裝訂商的學徒，學習很多並且受益於這些經驗。 As the tour progressed, Davy considered Faraday more and more as a colleague. Lady Davy, however, looked upon him as a servant, which led to frequent unpleasantness and embarrassments for Faraday.當旅行過程中，德維覺得法拉第越來越像他的同事。德維女士只是把他看作是一位僕人，使得法拉第頻頻感到不愉快和困惑。 After Davy and Faraday returned to London and the Royal Institution, Davy continued to be an important influence on Faradays development. Davy had a quick, penetrating mind, wide-ranging interests, and read extensively about chemistry, physics, poetry, and metaphysics. Faraday continued his work in chemistry with enthusiasm. In 1816 he published his first paper, Analysis of Caustic Lime of Tuscany. In 1818 Faraday worked with a manufacturer of surgical instruments to develop alloys of steel which would not rust. His combinations of iron with platinum and with silver were successful from a metallurgical point of view, but the alloys were too expensive to be commercialized. Nevertheless, he had demonstrated that science could help in producing better grades of steel. By 1820 Faraday had established a modest reputation as an analytical chemist.德維和法拉第在返回倫敦和皇家學院之後，德維繼續當個對法拉第的發展有重大影響的人。德維既機伶，又有透徹的心思，廣泛的興趣，並且廣泛的涉及化學，物理學，詩和哲學。法拉第持續抱著熱忱於化學方面的工作。在1816年他發表了他的第一份論文， 托斯卡納生鍛石的分析。 在1818年法拉第與一個儀器的製造商發展出不鏽鋼的合金。他用冶金術的觀點成功的結合鐵.鉑.銀，但是合金太昂貴而不能商品化。雖然如此，他已經證明科學能促進生產更好的鋼。身為一位分析化學家，法拉第已在1820年建立了謙遜的名聲。 In addition to Faradays work in chemistry and electricity, he was courting Sarah Bernard, the sister of one of his friends at the City Philosophical Society, who was also a Sandemanian . She and Faraday were mated in 1821, and Mrs. Faraday joined her husband residing at the Royal Institution. It was a happy marriage, and they lived at the institution until they moved to their retirement home in the grounds of Hampton Court. They had no children.除在化學和電方面的法拉第的工作之外，他向在皇家學院的朋友的妹妹撒拉巴納德求愛，她也是山地門教徒。在1821年她和法拉第結為夫妻，並且一起住在皇家學院裡，這是一樁幸福的婚姻，他們一直住在學院裡直到退休後搬到漢普頓科爾特。他們始終沒有孩子。 In the summer of 1820, Oersted announced his discovery that a wire conducting electric current creates a magnetic field surrounding it. Very quickly editors of scientific journals were flooded with papers on the phenomenon. Theories abounded, and there were scant resources available to sort fact from fiction. In 1821 in London, Richard Phillips, an editor of The Annals of Philosopy, asked his friend Faraday to help him understand what was occurring in Oersteds experiment, and to prepare a short history of electricity and magnetism. Faraday considered himself a chemist, but he reluctantly agreed to help. Oersted had explained that an electrical conflict surrounded a wire carrying electric current, and that the conflict performs circles.在1820年夏天，奧斯特宣佈他的發現即電流磁效應。很快地科學雜誌編輯很多關於奧斯特的發現。理論較多，且缺乏充足的資源去證實事實。在1821年的倫敦，理查菲利普斯，一名物理年表的編輯， 要他的朋友法拉第幫助他理解奧斯特的實驗過程中發生什麼，並且準備電和磁的簡短史。法拉第認為他自己是一位化學家，而他卻勉強地同意幫忙。奧斯特 解釋 電的衝突 圍繞電線傳播電流則 衝突完成一循環。 In preparation for Phillipss task, Faraday repeated many classical experiments in electricity and magnetism. He then began his investigation of Oersteds discovery by using a wire carrying current and a compass with a short magnetic needle to indicate the magnetism. As he moved the compass around the wire and back to its original position, he observed that the needle made one complete revolution. From this, he theorized that a magnetic pole would rotate indefinitely around a wire carrying current as long as the current was flowing. To demonstrate to himself that his theory was correct, he devised two experiments, illustrated in the cross-section diagrams of Figure 19.2.為菲利普斯的任務作準備，法拉第在電和磁性方面重複很多實驗。他開始調查奧斯特發現使用一電線帶著電流和一指南針發現磁針指向一磁場方向。 當他在電線周遭移動這個指南針並且返回到它的原先的位置，他觀察指針做一次完全的轉動。從這，他創立學說只要電流流動，磁極將在帶電流的電線周遭不定期旋轉。為了證明自己的理論是正確的，他設計出兩個實驗，在圖19.2的橫截面圖解裡說明。Figure19.2 Rotation of a magnetic pole around a current-carrying wire, and of a current-carrying wire around a magnetic pole. Forces in Newtons gravity, and in Coulombs experiments of static electricity and magnetism, acted in straight lines between bodies, or centers, which were well separated from each other. Scientists in 1820 thought of all forces in these terms; they called them central forces. Oersted and Faraday, however, were encouraging forces that acted in circles. Not being skilled in mathematics, Faraday began to explain this new phenomenon in experimental terms by postulating circular lines of force. Faraday reported his findings in a paper On Some New Electro-Magnetical Motions, and on the Theory of Magnetism, which was published in the Quarterly Journal of Science (October 21, 1821). It was the first report that electrical energy had been converted into continuous mechanical rotation.在牛頓的重力方面的力量，並且在庫侖的靜電和磁性的實驗過程中，在本身或者中心之間的直線裡行動，正好與彼此分離。科學家在1820年把這些權限裡的所有力量；他們叫它們為中心力。奧斯特和法拉第正進行線圈的力量實驗。由於不是擅長數學，法拉第透過實驗術語開始假設線圈的力量並解釋這個新現象。法拉第在一篇文章裡報告他的結論 在一些新電磁的運動，和關於磁性的理論， 被在科學(1821年10月21日)的季刊裡出版 . 第一個報告是電能可變為連續的機械旋轉，。 Unpleasantness followed the publication. William Wollaston was vice president of the Royal Society, and a skilled experimenter. He had conferred with Davy, who was the societys president, several times in the spring of 1821 and expressed to him the idea that the circular forces surrounding a cond