登陆注册
4714000000025

第25章

Magnetization of light.

But we must quit the man and go on to the discoverer: we shall return for a brief space to his company by-and-by. Carry your thoughts back to his last experiments, and see him endeavouring to prove that induction is due to the action of contiguous particles.

He knew that polarized light was a most subtle and delicate investigator of molecular condition. He used it in 1834 in exploring his electrolytes, and he tried it in 1838 upon his dielectrics. At that time he coated two opposite faces of a glass cube with tinfoil, connected one coating with his powerful electric machine and the other with the earth, and examined by polarized light the condition of the glass when thus subjected to strong electric influence. He failed to obtain any effect; still he was persuaded an action existed, and required only suitable means to call it forth.

After his return from Switzerland he was beset by these thoughts; they were more inspired than logical: but he resorted to magnets and proved his inspiration true. His dislike of 'doubtful knowledge' and his efforts to liberate his mind from the thraldom of hypotheses have been already referred to. Still this rebel against theory was incessantly theorising himself. His principal researches are all connected by an undercurrent of speculation. Theoretic ideas were the very sap of his intellect--the source from which all his strength as an experimenter was derived. While once sauntering with him through the Crystal Palace, at Sydenham, I asked him what directed his attention to the magnetization of light. It was his theoretic notions. He had certain views regarding the unity and convertibility of natural forces; certain ideas regarding the vibrations of light and their relations to the lines of magnetic force; these views and ideas drove him to investigation. And so it must always be: the great experimentalist must ever be the habitual theorist, whether or not he gives to his theories formal enunciation.

Faraday, you have been informed, endeavoured to improve the manufacture of glass for optical purposes. But though he produced a heavy glass of great refractive power, its value to optics did not repay him for the pains and labour bestowed on it. Now, however, we reach a result established by means of this same heavy glass, which made ample amends for all.

In November, 1845, he announced his discovery of the 'Magnetization of Light and the Illumination of the Lines of Magnetic Force.'

This title provoked comment at the time, and caused misapprehension.

He therefore added an explanatory note; but the note left his meaning as entangled as before. In fact Faraday had notions regarding the magnetization of light which were peculiar to himself, and untranslatable into the scientific language of the time. Probably no other philosopher of his day would have employed the phrases just quoted as appropriate to the discovery announced in 1845.

But Faraday was more than a philosopher; he was a prophet, and often wrought by an inspiration to be understood by sympathy alone.

The prophetic element in his character occasionally coloured, and even injured, the utterance of the man of science; but subtracting that element, though you might have conferred on him intellectual symmetry, you would have destroyed his motive force.

But let us pass from the label of this casket to the jewel it contains.

'I have long,' he says, 'held an opinion, almost amounting to conviction, in common, I believe, with many other lovers of natural knowledge, that the various forms under which the forces of matter are made manifest have one common origin; in other words, are so directly related and mutually dependent, that they are convertible, as it were, into one another, and possess equivalents of power in their action.... This strong persuasion,' he adds, 'extended to the powers of light.' And then he examines the action of magnets upon light. From conversation with him and Anderson, I should infer that the labour preceding this discovery was very great. The world knows little of the toil of the discoverer. It sees the climber jubilant on the mountain top, but does not know the labour expended in reaching it. Probably hundreds of experiments had been made on transparent crystals before he thought of testing his heavy glass.

Here is his own clear and simple description of the result of his first experiment with this substance:--'A piece of this glass, about two inches square, and 0.5 of an inch thick, having flat and polished edges, was placed as a diamagnetic between the poles (not as yet magnetized by the electric current), so that the polarized ray should pass through its length; the glass acted as air, water, or any other transparent substance would do; and if the eye-piece were previously turned into such a position that the polarized ray was extinguished, or rather the image produced by it rendered invisible, then the introduction of the glass made no alteration in this respect. In this state of circumstances, the force of the electro-magnet was developed by sending an electric current through its coils, and immediately the image of the lamp-flame became visible and continued so as long as the arrangement continued magnetic. On stopping the electric current, and so causing the magnetic force to cease, the light instantly disappeared. These phenomena could be renewed at pleasure, at any instant of time, and upon any occasion, showing a perfect dependence of cause and effect.'

In a beam of ordinary light the particles of the luminiferous ether vibrate in all directions perpendicular to the line of progression; by the act of polarization, performed here by Faraday, all oscillations but those parallel to a certain plane are eliminated.

同类推荐
  • 北洋水师章程

    北洋水师章程

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 南山祖师礼赞文

    南山祖师礼赞文

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 科场条贯

    科场条贯

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 佛说佛地经

    佛说佛地经

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • THE BROTHERS KARAMAZOV

    THE BROTHERS KARAMAZOV

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
热门推荐
  • 农门娘子不可欺

    农门娘子不可欺

    共妻?不行!坚决不能同意!作为一个受过高等教育的知识分子,疏馨表示这个身份真的难以接受!什么?十两三钱买的?给你们一百两让你们一人娶一房媳妇怎么样?!不乐意?大哥们,行行好吧,给条生路吧……
  • 余生愿与你一起

    余生愿与你一起

    “冷夜寒,你松开,当初你让我走的时候我说什么了?呵……”夏凉希转过去头倔强的说道。”我……”看着冷夜辰欲言又止的模样,夏凉希的心终究还是被那个被那个曾经视她如珍宝的男人伤透了。
  • 重卡战车在末世

    重卡战车在末世

    “总有刁民想害朕!”“世界末日马上就要来了,我必须生存下去!”受迫害妄想症患者沈聪,从网上看到别人说末日来临,立刻相信了这个说法,躲在家里不出门了,一心打造属于自己的末日战车,磨练自己的生存能力。直到有一天。真的世界末日了。……重卡②群:320472663;订阅群:548506816。新书《钢铁战警》已发,各位书友鼎力支持!
  • 薄冰之舞

    薄冰之舞

    无论你承认不承认,青春美文业已成为90年代文坛的一道风景。祝勇、邓皓、董文婷、周德东……当青春美文作家们的名字频频出现在全国大小期刊和报纸副刊上时,他们年轻的面孔和新鲜的笔触,他们带有鲜明时代特点的情绪和故事,都为自己的成长和定型亮出了一张张显眼的招牌……
  • 翡翠恋人

    翡翠恋人

    结婚两年,婆婆强迫我去做不孕检查,结果查出排卵障碍……婆婆对我不满,而我意外发现,丈夫和我资助了五年的女大学生关系暧昧。婚姻破裂,我对丈夫和婆婆失望之极,你们还想要夺取我的财产,我决定报复!
  • 苏联末日观察

    苏联末日观察

    本书从总体上记叙和分析了当年世界第二超级大国沦落过程中的内外重大事件,反映了作者对这些事件的看法。
  • 培养皿13号

    培养皿13号

    孤独。灵幻。诡疾。生而为人,或不为人,有多容易。
  • 七修续稿

    七修续稿

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 八识规矩通说

    八识规矩通说

    本书为公版书,为不受著作权法限制的作家、艺术家及其它人士发布的作品,供广大读者阅读交流。汇聚授权电子版权。
  • 洪荒天子(7)

    洪荒天子(7)

    洪荒中,毒虫遍地,异兽出没,危机无处不在,这便是始前的死亡之地。然而人类以天生的本能存于天地间,而他们之中的强者以神自居,用智慧与力量瓜分洪荒,分别统治着这片危机四伏的土地,从而形成了洪荒万国。而就在这血腥与杀劫之间,一位在蛇腹中、沼泽内、神剑下、陷阱里生存下来的少年,就在这野蛮与文明、毁灭与建设的洪流中崛起。他得到了苍天的眷恋,与神龙之丹融为一体,在广成洞府内开启心灵之门,悟透了天地的玄机,看遍了人世的杀戮争斗,孕育出无穷的智慧和能量,终铸就其不死之身,超越了凡尘的一切,游历于洪荒万国之间,组成“龙之旅”,横扫八荒,一统万国,创下了神州大地的千秋功业。他就是战神轩辕——洪荒天子!