The English chemist and physicist Michael Faraday, b. Sept. 22, 1791, d.Aug. 25, 1867, is known for his pioneering experiments in electricity andmagnetism. Many consider him the greatest experimentalist who ever lived.
Several concepts that he derived directly from experiments, such as lines of magnetic force, have become common ideas in modern physics.
Faraday was born at Newington, Surrey, near London. He received little more than a primary education, and at the age of 14 he was apprenticed to a bookbinder. There he became interested in the physical and chemical works of the time. After hearing a lecture by the famous chemist Humphry Davy, he sent Davy the notes he had made of his lectures. As a result Faraday was appointed, at the age of 21, assistant to Davy in the laboratory of the Royal Institution in London.
During the initial years of his scientific work, Faraday occupied himself mainly with chemical problems. He discovered two new chlorides of carbon and succeeded in liquefying chlorine and other gases. He isolated benzene in 1825, the year in which he was appointed director of the laboratory.
Davy, who had the greatest influence on Faradays thinking, had shown in 1807 that the metals sodium and potassium can be precipitated from their compounds by an electric current, a process known as electrolysis.
Faradays vigorous pursuit of these experiments led in 1834 to what became known as Faradays laws of electrolysis.
Faradays research into electricity and electrolysis was guided by the belief that electricity is only one of the many manifestations of the unified forces of nature, which included heat, light, magnetism, and chemical affinity. Although this idea was erroneous, it led him into the field of electromagnetism, which was still in its infancy.
In 1785, Charles Coulomb had been the first to demonstrate the manner in which electric charges repel one another, and it was not until 1820 that Hans Christian Oersted and Andre Marie Ampere discovered that an electric current produces a magnetic field. Faradays ideas about conservation of energy led him to believe that since an electric current could cause a magnetic field, a magnetic field should be able to produce an electric current. He demonstrated this principle of induction in 1831. Faraday expressed the electric current induced in the wire in terms of the number of lines of force that are cut by the wire.
The principle of induction was a landmark in applied science, for it made possible the dynamo, or generator, which produces electricity by mechanical means.
Faradays introduction of the concept of lines of force was rejected by most of the mathematical physicists of Europe, since they assumed that electric charges attract and repel one another, by action at a distance, making such lines unnecessary. Faraday had demonstrated the phenomenon of electromagnetism in a series of experiments, however.
This experimental necessity probably led the physicist James Clerk Maxwell to accept the concept of lines of force and put Faradays ideas into mathematical form, thus giving birth to modern field theory.
Faradays discovery that an intense magnetic field can rotate the plane of polarized light is known today as the Faraday effect. The phenomenon has been used to elucidate molecular structure and has yielded information about galactic magnetic fields.
Faraday described his numerous experiments in electricity and electromagnetism in three volumes entitled Experimental Researches in Electricity ; his chemical work was chronicled in Experimental Researches in Chemistry and Physics . Faraday ceased research work in 1855 because of declining mental powers, but he continued as a lecturer until 1861. A series of six childrens lectures published in 1860 as The Chemical History of a Candle, has become a classic of science literature.
迈克尔法拉第英国物理学家、化学家,也是著名的自学成才的科学家。生于萨里郡纽因顿一个贫苦铁匠家庭。仅上过小学。1831年,他作出了关于力场的关键性突破,永远改变了人类文明。1815年5月回到皇家研究所在戴维指导下进行化学研究。1824年1月当选皇家学会会员,1825年2月任皇家研究所实验室主任,1833----1862任皇家研究所化学教授。1846年荣获伦福德奖章和皇家勋章。
上一篇: SAT写作经典例子之林书豪
下一篇: SAT优秀作文欣赏(5)
YouTube愚人节恶作剧:宣布网站关闭10年
体坛英语资讯:Frenchwoman Frappart makes history by officiating UEFA Super Cup
凯特王妃身怀六甲仍穿高跟 玩篮球打乒乓不亦乐乎
H7N9新药帕拉米韦获批上市 适用流感危重病人
伦敦警方出新招 破不了案就送花
电子香烟:烟草业巨头面临一大挑战
美康涅狄格州出台最严控枪法案
男人对自身长相更满意 幸福感更高
国际英语资讯:World shows concerns over humanitarian situation caused by rains, floods in Sudan
“地球之肺”在燃烧!巴西派军队赴亚马孙雨林灭火
清明时节雨纷纷:外出扫墓注意防寒
国内英语资讯:Chinese vice premier stresses promoting healthy development of intelligent industry
国际英语资讯:Brazil, Colombia discuss joint plan over Amazon
哭笑不得: 北京污染赶跑外国人
体坛英语资讯:Spartak Trnava ousted from Europa League qualifiers
现实版全职美人鱼翩翩起舞 “尾巴”造价1万英镑
美国熊孩子考卷上的神回答:你会给他打多少分?
乐天派生活手册:保持快乐心情的5个小秘密
张国荣逝世十周年:哥哥我们想你
印度发明防强奸内衣 配全球定位系统