乔治·斐兹杰惹George FitzGerald

乔治·斐兹杰惹是一位杰出的数学物理学家，如今大多数科学家都知道他是相对论中斐兹杰惹-亨德里克·洛伦兹收缩的提出者之一。然而，正如我们将在下面看到的，斐兹杰惹的这一建议并不属于他进行大部分研究的领域，他肯定不会将此视为他最伟大的贡献。

斐兹杰惹的父母是William FitzGerald和Anne Frances Stoney。他的父亲William是爱尔兰新教教会的牧师，在斐兹杰惹出生时是都柏林圣安妮教堂的教区长。William虽然本人没有科学兴趣，但是一位知识分子，后来成为科克主教，之后又成为基拉卢主教。斐兹杰惹后来对形而上学的兴趣似乎来自他父亲一方。斐兹杰惹的母亲是来自国王郡Birr的斐兹杰惹 Stoney的女儿，她也出身于知识分子家庭。Anne的兄弟斐兹杰惹 Johnstone Stoney当选为伦敦皇家学会会士，而斐兹杰惹对数学和物理的喜爱似乎主要来自他母亲一方。

William和Anne有三个儿子，斐兹杰惹是三个中的中间一个。Maurice FitzGerald是斐兹杰惹的两个兄弟之一，也在科学领域取得了学术成就，成为贝尔法斯特女王学院的工程学教授。斐兹杰惹在家上学，与兄弟姐妹一起由M A Boole辅导，后者是乔治·布尔的姐妹。Boole小姐是否意识到她的学生斐兹杰惹拥有多么巨大的潜力，这一点值得怀疑，因为尽管他在算术和代数方面表现出色，但在语言方面并不比一般学生强，而且语言记忆力相当差。然而，当辅导进展到学习欧几里得的Elements时，斐兹杰惹确实表现出非常强的能力，他还表现出对机械构造的巨大创造力，手非常灵巧。他也是个运动型男孩，但不太喜欢游戏。

布尔小姐为她的学生们的大学生活做了很好的准备。她注意到她的学生斐兹杰惹有一个非凡的才能，那就是他作为观察者的技能。许多年后，斐兹杰惹显然想到了自己的青年时代，写道：-

培养和训练做事以及从观察、实验和测量中学习的实际能力，是教育的一部分，牧师和律师或许可以忽视，因为他们必须处理情感和言辞，但医生和工程师若忽视，就只能自担风险，并危及雇用他们的人。这些习惯应在孩子性格形成的最早几年就精心培养。嫩枝弯曲，树便倾斜。

斐兹杰惹无疑表明他已获得从观察、实验和测量中学习的能力。他年仅16岁就进入都柏林圣三一学院学习他最好的两门科目——数学和实验科学，并很快将在家接受的训练派上了用场。在圣三一学院，斐兹杰惹[8]：-

……以轻松的姿态获得了他道路上的一切荣誉，并以优雅的风度佩戴它们，这使他赢得了对手和同代人的喜爱。

然而，这并不是一段完全专注于学业的本科生涯，因为斐兹杰惹充分参与了文学社团和社交俱乐部。他还继续着自己的运动兴趣，投身于体操和球拍运动。1871年，他作为数学和实验科学两门学科的最优秀学生毕业。他在所选科目中赢得了一项大学奖学金和两项一等高级 moderator 资格。

斐兹杰惹现在的目标是赢得三一学院 fellowship，但当时这些职位很少且间隔很长。他花了六年时间学习才获得他想要的 fellowship，但在这几年里，他奠定了研究事业的基础。他研究了约瑟夫·拉格朗日、皮埃尔·西蒙·拉普拉斯、恩斯特·弗朗茨·诺伊曼的著作，以及他自己的同胞威廉·哈密顿和詹姆斯·麦古拉的著作。此外，他还吸收了奥古斯丁·路易·柯西和乔治·格林提出的理论。然后，在1873年，出现了一篇将在他未来发挥重要作用的出版物。这就是詹姆斯·克拉克·麦克斯韦的Electricity and Magnetism，它首次包含了四个偏微分方程，现在被称为詹姆斯·克拉克·麦克斯韦方程组。斐兹杰惹立即将詹姆斯·克拉克·麦克斯韦的工作视为为进一步发展提供了框架，并开始致力于推进这一理论。

值得注意的是，斐兹杰惹对詹姆斯·克拉克·麦克斯韦基础论文的反应并非大多数科学家的反应。很少有人似乎将这一理论视为起点，相反，大多数人只将其视为产生詹姆斯·克拉克·麦克斯韦自己结果的手段。斐兹杰惹作为科学家的洞察力值得称赞，他从一开始就清楚地看到了Electricity and Magnetism的重要性。用奥利弗·赫维赛德的话说，詹姆斯·克拉克·麦克斯韦的理论多年来“相当不发达且鲜为人知”，但少数其他人，包括奥利弗·赫维赛德、海因里希·鲁道夫·赫兹和亨德里克·洛伦兹，将与斐兹杰惹持相同看法。在接下来的几年里，斐兹杰惹将与这三位科学家交流思想。

在争取 fellowship 的六年里，斐兹杰惹还研究了形而上学，这是他在本科时没有正式学习过的主题，他特别被乔治·伯克利的哲学所吸引。他对形而上学的喜爱和对该主题的深刻理解，与他在未来职业生涯中的其他伟大才能相结合。他赢得了 fellowship，并于1877年成为都柏林三一学院的导师。这不是他第一次尝试赢得 fellowship，而是第二次，因为他在第一次尝试时未能赢得 fellowship。在三一学院，他隶属于实验物理系，很快他就对该学院的物理科学教学产生了最大的影响。

1881年，都柏林的自然哲学教授弗瑞兹·约翰 R Leslie去世，斐兹杰惹接替他担任 Erasmus Smith 自然与实验哲学讲席。在任命时，他放弃了学院导师的职责，这是一个他曾极为成功的角色，以专注于教授的职责。斐兹杰惹在都柏林三一学院的长期斗争之一是增加实验物理的教学量。他很快在他能够获得使用的一间旧化学实验室里开设了课程，并聚集了能帮助该学科实践方面的同事。然而，正如大学中经常发生的那样，由于缺乏资金，他能取得的进展受到限制。

在1896年给爱尔兰工业联盟所做的一次演讲中，斐兹杰惹强调了他终生对实践研究的信念：-

我们现行体系的错误在于，以为学会使用词语就能教会我们使用事物。这还算是它最好的情况。它实际上甚至没有教会孩子们使用词语，只是教他们学习词语，用短语塞满记忆，成为一群鹦鹉，用难以消化的冗词赘语窒息思想。以实验为例。你怎么能教孩子们用词语做细致的实验呢？然而，他们能够从实验中学到东西，这一点至关重要。

然而，实际应用建立在理论基础之上，斐兹杰惹完全理解这一点。1900年2月22日，他作为电气工程师学会都柏林分会主席发表就职演讲时，谈到了19世纪电如何被应用于造福人类。在电报这样的实际发明背后，有着大量的理论工作：-

……电报在很大程度上归功于欧几里得和其他纯粹几何学家，归功于发明了我们的记数法和代数的希腊和阿拉伯数学家，归功于创立动力学的伽利略和艾萨克·牛顿，归功于发明微积分的艾萨克·牛顿和哥特弗里德·威廉·莱布尼茨，归功于发现伏打电堆的伏打，归功于发现电流磁效应的奥斯特，归功于发现电流作用定律的安德烈-马里·安培，归功于发现导线电阻定律的格奥尔格·欧姆，归功于惠斯通、麦可·法拉第、开尔文、詹姆斯·克拉克·麦克斯韦、海因里希·鲁道夫·赫兹。没有这些抽象科学家的发现、发明和理论，电报就不可能像现在这样。

我们还应该看看斐兹杰惹关于大学目的的看法，因为与他的其他教育信念一样，这是他如何履行教授职责的驱动力。他认为，大学的首要目的不是教授少数来上学的学生，而是通过研究来教育所有人。他在1892年写道：-

大学的职能主要是教育人类。……在任何时代，最伟大的人物始终认为，他们的首要职责是发现新知识，为全人类创造新思想，而不是教导少数碰巧住在他们附近的人。……大学是将当代最先进智识的精力用于教育整个国家，还是用于教育少数父母有能力供他们接受——在某些地方是幻想中的——只有富人才能获得的教育的人？

从我们引用的斐兹杰惹著作中的段落可以看出，他对教育的兴趣远远超出了他自己系科的狭窄范围。这不仅仅是一种理论兴趣，因为忠于自己的信念，他在教育中发挥了非常实际的作用。他从1888年起担任伦敦大学的物理考官，并于1898年担任爱尔兰国家教育专员，致力于改革爱尔兰的初等教育。作为这项任务的一部分，他于1898年秋天前往美国进行实地考察。正如人们可能预料的那样，他的目标是将更多实用主题纳入小学教学大纲。在他去世时，他正参与爱尔兰中等教育的改革，并且还在考虑技术教育的委员会中任职。

1883年，斐兹杰惹与Harriette Mary Jellett结婚。她是三一学院教务长J H Jellett牧师的女儿，也是一位杰出的科学家，曾获得皇家学会颁发的皇家奖章。正是通过他与Jellett的私人友谊以及他们共同的科学研究，斐兹杰惹结识了Harriette。尽管在斐兹杰惹去世时，这对夫妇结婚还不到八年，但在此期间他们育有八个孩子：三个儿子和五个女儿。斐兹杰惹于1883年当选为皇家学会会士，并且像他的岳父一样，他也将获得该学会的皇家奖章。这是在1899年，这一享有盛誉的奖项授予斐兹杰惹，以表彰他对理论物理学的贡献，特别是对光学和电动力学的贡献。Lister勋爵在颁发奖章时说[3]：-

他的批判性活动遍及一个无垠的领域，自始至终因丰富想象的成果而充满活力并得到充实。

我们现在应该考察一下斐兹杰惹因之获得这些荣誉的研究。

从1876年开始，在获得奖学金之前，斐兹杰惹开始发表他的研究成果。他的第一部作品On the equations of equilibrium of an elastic surface填补了约瑟夫·拉格朗日研究的一个问题的案例。同年他的第二篇论文是关于磁学的，然后，仍在1876年，他在Proceeding of the Royal Society上发表了On the rotation of the plane of polarisation of light by reflection from the pole of a magnet。他已经开始为詹姆斯·克拉克·麦克斯韦的理论做出贡献，除了理论贡献外，他还在进行电磁理论的实验。他的第一个主要理论贡献是On the electromagnetic theory of the reflection and refraction of light，他于1878年10月将其寄给皇家学会。詹姆斯·克拉克·麦克斯韦在审阅该论文时指出，斐兹杰惹正在以与亨德里克·洛伦兹大致相同的总体方向发展他的思想。

在1883年于绍斯波特举行的英国协会会议上，斐兹杰惹作了一场讨论电磁理论的演讲。他提出了一种产生波长相对较短的电磁扰动的方法：-

……通过利用当蓄电池通过小电阻放电时产生的交流电。就有可能产生波长小至10米或更短的波。

斐兹杰惹利用自己对电动力学的研究，在1883年提出振荡电流会产生电磁波。然而，正如他后来所写：-

……我没有看到任何可行的办法来检测这种诱导共振。

1888年，斐兹杰惹在巴斯以主席身份向英国协会的数学与物理分会发表演讲。他得以向英国协会报告，海因里希·鲁道夫·赫兹已于当年早些时候通过实验验证了这一点。海因里希·鲁道夫·赫兹已经证实，电磁波的振动、反射和折射与光的振动、反射和折射相同。在这场面向普通听众的精彩演讲中，斐兹杰惹描述了海因里希·鲁道夫·赫兹如何：-

……观察到了与光的干涉十分类似的电磁波干涉。

就任讲席之后，斐兹杰惹继续提出了许多创新性的想法，但没有提出重大理论。例如，尽管他有关于电磁波的想法，他并没有将研究进行到底，最终的实验验证是由海因里希·鲁道夫·赫兹完成的。其原因或许可以通过斐兹杰惹于1889年2月4日写给奥利弗·赫维赛德的一封信中的一段引文来最好地理解（例如见[1]）：-

我远远地钦佩那些能够克制自己、直到把结果研究透彻的人，但我对自己犯错误一点也不敏感，所以我会带着各种粗糙的想法冲出来，希望它们能让别人思考并带来某些进展。

斐兹杰惹在这段引文中谦虚地淡化了自己的贡献，但他对自己的评价基本上是正确的。O J Lodge [9]对斐兹杰惹的工作给出了类似但更公允的分析：-

……长期耐心的分析所带来的从容并不属于他，他的天赋也并非全然在此方向：他最好的状态，是在讨论的激发下，头脑中涌现出大量精彩的想法，其中一些他立即着手用粗略的定量计算加以检验，而他极擅长辨识出所需的数据。他拥有非凡的能力，能瞬间把握一个难题的所有关联……

奥利弗·赫维赛德再次写道（例如见[8]）：——

毫无疑问，他拥有所有人中最敏捷、最具原创性的头脑。这是一项巨大的殊荣；但我想，就他的科学声誉而言，这却是一种不幸。他看到太多可能性。他的头脑过于多产、过于富有创造力。我认为，如果他稍微迟钝一些——我的意思是，不那么敏捷和多才多艺，而是更加埋头苦干——对他会更好。除了少数人之外，他会得到更好的赏识。

最后，我们应当考察斐兹杰惹今天举世闻名的贡献。曾有许多尝试试图探测地球相对于以太的运动，以太是一种被假定为在空间中承载光波的介质。A A Michelson和E W 法兰克·莫雷进行了一项精确实验，比较沿地球运动方向的光速与垂直于地球运动方向的光速。尽管相对于以太的运动存在差异，光速却被发现是相同的。1889年，即Michelson-莫雷实验两年后，斐兹杰惹提出，物体因接近光速的运动而收缩，可以解释该实验的结果。Lodge [9]写道，这一想法：——

……在利物浦这位作者的书房里，当他正在讨论Michelson-莫雷实验的意义时，突然闪现在他脑海中。

亨德里克·洛伦兹于1895年独立地给出了同一类更为详细的描述。这两位伟人的典型之处在于，两人都极其乐于承认对方的贡献，但几乎毫无疑问，两人是各自独立地产生了这一想法。斐兹杰惹-亨德里克·洛伦兹收缩现在在相对论中扮演着重要角色。

斐兹杰惹去世时年仅49岁。詹姆斯·克拉克·麦克斯韦的工作对斐兹杰惹来说如此基础，他去世时48岁，而海因里希·鲁道夫·赫兹去世时36岁。事实上，1896年，在海因里希·鲁道夫·赫兹去世后，斐兹杰惹为Nature审阅了Hertz的Miscellaneous Papers的出版。四年后，1900年9月，斐兹杰惹开始抱怨消化不良，并开始不得不注意饮食。几周后，他抱怨发现自己难以集中精力思考一个问题。他的健康迅速恶化，尽管做了手术，结局还是很快到来。

W Ramsay，在听说斐兹杰惹去世时写道（见[8]）：-

……对我来说，如同对许多人一样，斐兹杰惹是最真诚的真朋友；无论是讨论个人事务，还是与科学或教育相关的事情，他总是感兴趣，总是同情，总是鼓励。然而，我怀疑是否仅凭这些品质就使他的存在如此吸引人、如此鼓舞人心。我认为，这是因为人们感到能够与一个远高于自己水平的人平等交谈，不仅在智力品质上，而且在各个方面。……他没有一丝智力上的骄傲；他从不自我吹嘘，也不渴望名声；他满足于尽自己的责任。而他将此视为帮助他人尽责任的任务。

斐兹杰惹被Lord 开尔文（开尔文）描述为（见[10]）：-

……生活在最高科学和智力品质的氛围中，但总是与每一位无论多么卑微的同事为伴。……在过去六七年里，在光的波动说和电与磁的以太理论方面，我与他的科学共鸣和联盟大大成熟了。

在他去世时，伦敦大学理学院通过了决议[3]：-

本次会议……怀着深切的悲痛获悉已故教授斐兹杰惹 Francis FitzGerald的早逝，希望记录下对其作为人、作为教师、作为研究者以及作为科学思想领袖的卓越品质的高度赞赏……

George FitzGerald was a brilliant mathematical physicist who today is known by most scientists as one of the proposers of the FitzGerald-Lorentz contraction in the theory of relativity. However, this suggestion by FitzGerald, as we shall see below, was not in the area in which he undertook most of his research, and he would certainly not have rated this his greatest contribution.

George FitzGerald's parents were William FitzGerald and Anne Frances Stoney. His father William was a minister in the Irish Protestant Church and rector of St Ann's Dublin at the time of George's birth. William, although having no scientific interests himself, was an intellectual who went on to become Bishop of Cork and later Bishop of Killaloe. It seems that George's later interest in metaphysics came from his father's side of the family. George's mother was the daughter of George Stoney from Birr in King's County and she was also from an intellectual family. George Johnstone Stoney, who was Anne's brother, was elected a Fellow of the Royal Society of London and George FitzGerald's liking for mathematics and physics seems to have come mainly from his mother's side of the family.

William and Anne had three sons, George being the middle of the three. Maurice FitzGerald, one of George's two brothers, also went on to achieve academic success in the sciences, becoming Professor of Engineering at Queen's College Belfast. George's schooling was at home where, together with his brothers and sisters, he was tutored by M A Boole, who was George Boole's sister. It is doubtful whether Miss Boole realised what enormous potential her pupil George had, for although he showed himself to be an excellent student of arithmetic and algebra, he was no better than an average pupil at languages and had rather a poor verbal memory. However, when the tutoring progressed to a study of Euclid's Elements then George showed himself very able indeed, and he also exhibited a great inventiveness for mechanical constructions, having great dexterity. He was also an athletic boy yet he had no great liking for games.

Miss Boole prepared her pupils very well for their university studies. She noticed one remarkable talent in her pupil George, that was his skill as an observer. Many years later FitzGerald, clearly thinking of his own youth, wrote:-

The cultivation and training of the practical ability to do things and to learn from observation, experiment and measurement, is a part of education which the clergyman and the lawyer can maybe neglect, because they have to deal with emotions and words, but which the doctor and the engineer can only neglect at their own peril and that of those who employ them. These habits should be carefully cultivated from the earliest years while a child's character is being developed. As the twig is bent so the tree inclines.

FitzGerald certainly showed that he had acquired the ability to learn from observation, experiment and measurement. He entered Trinity College Dublin at the young age of 16 to study his two best subjects which were mathematics and experimental science, and he was soon putting the training he had received at home to good use. At Trinity College, FitzGerald [8]:-

... attained all the distinctions that lay in his path with an ease, and wore them with a grace, that endeared him to his rivals and contemporaries.

It was not an undergraduate career devoted entirely to study, however, for FitzGerald played a full part in literary clubs and social clubs. He also continued his athletic interests, taking to gymnastics and to racquet sports. In 1871 he graduated as the best student in both mathematics and experimental science. He won a University Studentship and two First Senior Moderatorships in his chosen topics.

The aim of FitzGerald was now to win a Trinity College Fellowship but at this time these were few and far between. He was to spend six years studying before he obtained the Fellowship he wanted, but during these years he laid the foundation of his research career. He studied the works of Lagrange, Laplace, Franz Neumann, and those of his own countrymen Hamilton and MacCullagh. In addition he absorbed the theories put forward by Cauchy and Green. Then, in 1873, a publication appeared which would play a major role in his future. This was Electricity and Magnetism by Maxwell which, for the first time, contained the four partial differential equations, now known as Maxwell's equations. FitzGerald immediately saw Maxwell's work as providing the framework for further development and he began to work on pushing forward the theory.

It is worth noting that FitzGerald's reaction to Maxwell's fundamental paper was not that of most scientists. Very few seemed to see the theory as a starting point, rather most saw it only as a means to produce Maxwell's own results. It is a tribute to FitzGerald's insight as a scientist that he saw clearly from the beginning the importance of Electricity and Magnetism. Maxwell's theory was for many years, in the words of Heaviside, "considerably underdeveloped and little understood" but a few others were to see it in the same light as FitzGerald including Heaviside, Hertz and Lorentz. FitzGerald would exchange ideas over the following years with all three of these scientists.

During the six years he spent working for the Fellowship, FitzGerald also studied metaphysics, a topic which he had not formally studied as an undergraduate, and he was particularly attracted to Berkeley's philosophy. His liking for metaphysics and his deep understanding of the topic combined with his other great talents in his future career. He won his Fellowship and became a tutor at Trinity College Dublin in 1877. This was not his first attempt at winning a Fellowship, rather it was his second since he failed to win a Fellowship at his first attempt. At Trinity College he was attached to the Department of Experimental Physics and soon he was exerting the greatest influence on the teaching of the physical sciences in the College.

In 1881 John R Leslie, the professor of natural philosophy at Dublin, died and FitzGerald succeeded him to the Erasmus Smith Chair of Natural and Experimental Philosophy. At the time of his appointment he gave up his duties as College tutor, a role in which he had been extremely successful, to concentrate on his duties as a professor. One of FitzGerald's long running battles at Trinity College Dublin was to increase the amount of teaching of experimental physics. He soon set up classes in an old chemical laboratory that he was able to obtain for his use, and he gathered round him colleagues who would help in the practical aspects of the subject. As is so often the case in universities, however, he was restricted in the progress he could make from a lack of funds.

In a lecture which he gave to the Irish Industrial League in 1896 FitzGerald emphasised his lifelong belief in practical studies:-

The fault of our present system is in supposing that learning to use words teaches us to use things. This is at its best. It really does not even teach children to use words, it only teaches them to learn words, to stuff their memories with phrases, to be a pack of parrots, to suffocate thought with indigestible verbiage. Take the case of experimenting. How can you teach children to make careful experiments with words? Yet it is great importance that they should be able to learn from experiments.

However, practical applications are built on theoretical foundations and FitzGerald fully understood this. In his inaugural lecture on 22 February 1900 as President of the Dublin Section of the Institution of Electrical Engineers, he spoke of how electricity had been applied to the benefit of mankind during the nineteenth century. Behind a practical invention such as telegraphy there was a wealth of theoretical work:-

... telegraphy owes a great deal to Euclid and other pure geometers, to the Greek and Arabian mathematicians who invented our scale of numeration and algebra, to Galileo and Newton who founded dynamics, to Newton and Leibniz who invented the calculus, to Volta who discovered the galvanic coil, to Oersted who discovered the magnetic actions of currents, to Ampère who found out the laws of their action, to Ohm who discovered the law of resistance of wires, to Wheatstone, to Faraday, to Lord Kelvin, to Clerk Maxwell, to Hertz. Without the discoveries, inventions, and theories of these abstract scientific men telegraphy, as it now is, would be impossible.

We should also look at FitzGerald's idea of the purpose of a university since it was, like his other educational beliefs, the driving force in how he carried out his professorial duties. He believed that the primary purpose of a university was not to teach the few students who attended but, through research, to teach everyone. He wrote in 1892:-

The function of the University is primarily to teach mankind. .. at all times the greatest men have always held that their primary duty was the discovery of new knowledge, the creation of new ideas for all mankind, and not the instruction of the few who found it convenient to reside in their immediate neighbourhood. ... Are the Universities to devote the energies of the most advanced intellects of the age to the instruction of the whole nation, or to the instruction of the few whose parents can afford them an - in some places fancy - education that can in the nature of things be only attainable by the rich?

As can be seen from the quotations we have given from FitzGerald's writing, his interest in education went well beyond the narrow confines of his own department. It was not merely a theoretical interest for, true to his own beliefs, he took a very practical role in education. He was an examiner in physics at the University of London beginning in 1888 and he served as a Commissioner of National Education in Ireland in 1898 being concerned with reforming primary education in Ireland. As part of this task he travelled to the United States on a fact finding tour in the autumn of 1898. As one might have expected, his aim was to bring far more practical topics into the syllabus of primary schools. At the time of his death he was involved in the reform of intermediate education in Ireland and he also served on the Board which was considering technical education.

In 1883 FitzGerald married Harriette Mary Jellett. She was the daughter of the Rev J H Jellett, the Provost of Trinity College and an outstanding scientist who had been awarded the Royal Medal by the Royal Society. It was through his personal friendship with Jellett, and also their joint scientific studies, that FitzGerald got to know Harriette. Although the couple had been married just under eight years at the time of FitzGerald's death, they had eight children during this time; three sons and five daughters. FitzGerald was elected a Fellow of the Royal Society in 1883 and, like his father-in-law, he was to receive its Royal medal. This was in 1899 when the prestigious award was made to FitzGerald for his contributions to theoretical physics, especially to optics and electrodynamics. Lord Lister, presenting the medal, said [3]:-

His critical activity pervades an unbounded field, enlivened and enriched throughout by the fruits of a luxuriant imagination.

We should now examine the research for which FitzGerald received these honours.

Beginning in 1876, before he obtained his Fellowship, FitzGerald began to publish the results of his research. His first work On the equations of equilibrium of an elastic surface filled in cases of a problem studied by Lagrange. His second paper in the same year was on magnetism and he then, still in the year 1876, published On the rotation of the plane of polarisation of light by reflection from the pole of a magnet in the Proceeding of the Royal Society. He had already begun to contribute to Maxwell's theory and, as well as theoretical contributions, he was conducting experiments in electromagnetic theory. His first major theoretical contribution was On the electromagnetic theory of the reflection and refraction of light which he sent to the Royal Society in October 1878. Maxwell, in reviewing the paper, noted that FitzGerald was developing his ideas in much the same general direction as was Lorentz.

At a meeting of the British Association in Southport in 1883, FitzGerald gave a lecture discussing electromagnetic theory. He suggested a method of producing electromagnetic disturbances of comparatively short wavelengths:-

... by utilising the alternating currents produced when an accumulator is discharged through a small resistance. It would be possible to produce waves of as little as 10 metres wavelength or less.

So FitzGerald, using his own studies of electrodynamics, suggested in 1883 that an oscillating electric current would produce electromagnetic waves. However, as he later wrote:-

... I did not see any feasible way of detecting the induced resonance.

In 1888 FitzGerald addressed the Mathematical and Physical Section of the British Association in Bath as its President. He was able to report to British Association that Heinrich Hertz had, earlier that year, verified this experimentally. Hertz had verified that the vibration, reflection and refraction of electromagnetic waves were the same as those of light. In this brilliant lecture, given to a general audience, FitzGerald described how Hertz:-

... has observed the interference of electromagnetic waves quite analogous to those of light.

After his appointment to the chair, FitzGerald had continued to produce many innovative ideas but no major theories. For example despite his ideas on electromagnetic waves he had not followed through the research and the final experimental verification had been achieved by Hertz. The reason for this is perhaps best understood with a quotation from a letter which FitzGerald sent to Heaviside on 4 February 1889 (see for example [1]):-

I admire from a distance those who contain themselves till they worked to the bottom of their results but as I am not in the very least sensitive to having made mistakes I rush out with all sorts of crude notions in hope that they may set others thinking and lead to some advance.

Although FitzGerald is modestly talking down his contributions in this quotation, the comment he made about himself is essentially correct. O J Lodge [9] gives a similar, but fairer, analysis of FitzGerald's work:-

... the leisure of long patient analysis was not his, nor did his genius altogether lie in this direction: he was at his best when, under the stimulus of discussion, his mind teemed with brilliant suggestions, some of which he at once proceeded to test by rough quantitative calculation, for which he was an adept in discerning the necessary data. The power of grasping instantly all the bearings of a difficult problem was his to an extraordinary degree ...

Again Heaviside wrote (see for example [8]):-

He had, undoubtedly, the quickest and most original brain of anybody. That was a great distinction; but it was, I think, a misfortune as regards his scientific fame. He saw too many openings. His brain was too fertile and inventive. I think it would have been better for him if he had been a little stupid -- I mean not so quick and versatile, but more plodding. He would have been better appreciated, save by a few.

Finally we should examine the contribution for which FitzGerald is universally known today. There had been many attempts to detect the motion of the Earth relative to the aether, a medium in space postulated to carry light waves. A A Michelson and E W Morley conducted an accurate experiment to compare the speed of light in the direction of the Earth's motion and the speed of light at right angles to the Earth's motion. Despite the difference in relative motion to the aether, the velocity of light was found to be the same. In 1889, two years after the Michelson-Morley experiment, FitzGerald suggested that the shrinking of a body due to motion at speeds close to that of light would account for the result of that experiment. Lodge [9] writes that the idea:-

... flashed on him in the writer's study at Liverpool as he was discussing the meaning of the Michelson-Morley experiment.

Lorentz, independently in 1895, gave a much more detailed description of the same kind. It was typical of these two great men that both were more than ready to acknowledge the contribution of the other, but there is little doubt that each had the idea independently of the other. The FitzGerald-Lorentz contraction now plays an important role in relativity.

Sadly FitzGerald died at the age of only 49 years. Maxwell, whose work had proved so fundamental for FitzGerald, had died at the age of 48 while Hertz died at the age of 36. In fact in 1896 FitzGerald had reviewed the publication of Hertz's Miscellaneous Papers for Nature after Hertz's death. Four years later, in September 1900, FitzGerald began to complain of indigestion and began to have to be careful what he ate. A few weeks later he complained that he was finding it difficult to concentrate on a problem. His health rapidly deteriorated and despite having an operation the end came quickly.

W Ramsay, on hearing of FitzGerald's death wrote (see [8]):-

... to me, as to many others, FitzGerald was the truest of true friends; always interested, always sympathetic, always encouraging, whether the matter discussed was a personal one, or one connected with science or with education. And yet I doubt if it were these qualities alone which made his presence so attractive and so inspiring. I think it was the feeling that one was able to converse on equal terms with a man who was so much above the level of one's self, not merely in intellectual qualities of mind, but in every respect. ... he had no trace of intellectual pride; he never put himself forward, and had no desire for fame; he was content to do his duty. And he took this to be the task of helping others to do theirs.

FitzGerald was described by Lord Kelvin (William Thomson) as (see [10]):-

... living in an atmosphere of the highest scientific and intellectual quality, but always a comrade with every fellow-worker of however humble quality.... My scientific sympathy and alliance with him have greatly ripened during the last six or seven years over the undulatory theory of light and the aether theory of electricity and magnetism.

On his death the Faculty of Science of the University of London adopted the resolution [3]:-

That this meeting ... having heard with profound sorrow of the premature death of the late Professor George Francis FitzGerald, desires to place on record its high appreciation of his brilliant qualities as a man, as a teacher, as an investigator, and as a leader of scientific thought ...