厄特沃什·罗兰Loránd Eötvös

厄特沃什·罗兰也以罗兰的德语版本之名而为人所知，即Roland。如果他只用匈牙利语发表，罗兰在国际声誉方面所取得的成就就会少得多，因此他最重要的成果既用匈牙利语发表，也用德语发表。因此，对国际科学界来说，他以这些德语论文上出现的名字而为人所知，即Roland，Baron Eötvös。然而，他的全称要显赫得多：在匈牙利语中是Vásárosnaményi Báro 罗兰 罗兰；在英语中是Roland，Baron Eötvös of Vásárosnaményi。查看今天的匈牙利地图，Vásárosnaményi靠近其与乌克兰的东部边界。

罗兰的母亲是Agnes Rosty。他的父亲是József，Baron Eötvös，一位小说家、散文家、教育家和政治家，其生平与著作都致力于创造现代匈牙利文学和建立现代民主的匈牙利。他是著名钢琴家和作曲家Franz Liszt的朋友。在罗兰出生时，他的父亲是1848年革命政府的教育部长，但在与领导政府的Lajos Kossuth发生分歧后，他于当年晚些时候辞职并前往慕尼黑，在那里一直住到1851年。当然，罗兰成长于一个地位很高的家庭，并受益于广泛的教育。他年轻时，罗兰的父亲聘请Gusztáv Keleti——当时美术学校的领导者、一位画家——来辅导他的儿子。罗兰很快在一系列艺术追求中展现出才华，他在绘画方面变得非常熟练，并写诗。他一生都在笔记本中速写旅行中所见的场景。

在学校里，罗兰学习匈牙利语、德语、数学、历史、地理、生物、矿物学和物理学。尽管数学和物理学对他特别有吸引力，但人们期望他遵循家族传统，学习法律，以此作为通往政府职位的道路。1865年他进入布达佩斯大学时，他遵从家族意愿，注册攻读法律学位。嗯，说他在布达佩斯大学学习并不完全准确，因为当时它是佩斯大学；直到1872年，佩斯城才与多瑙河对岸的布达城合并，形成布达佩斯。

罗兰对数学和科学的兴趣始终超过对法律的兴趣，他在大学修读法律课程期间，私下跟随Otto Petzval学习数学。József 罗兰看到儿子对科学着迷，便请大学的矿物学教授给年轻的罗兰讲授科学。他还在大学里Charles Than的化学实验室工作，并很快决定放弃法律，完全专注于科学。

他于1867年终止了法律学业，前往海德堡学习，师从古斯塔夫·基尔霍夫、赫尔曼·冯·亥姆霍兹和本生。显然他是个典型的学生，因为他曾因夜间与同学在街上唱歌太大声而受到警察警告！从海德堡他去了柯尼斯堡，师从恩斯特·弗朗茨·诺伊曼和弗里德里希·里歇洛。他回到海德堡，于1870年获得博士学位，学位论文研究的是阿尔芒·斐索关于光源相对运动的问题。这是迈向相对论的最早步骤之一。在国外的那几年对罗兰的发展是极其重要的时期[1]：-

他的教授们深刻影响了罗兰的工作习惯。古斯塔夫·基尔霍夫教给他精确测量的重要性。赫尔曼·冯·亥姆霍兹喜欢尽可能多花时间与学生相处，向罗兰展示了个人讨论的价值。他的理论物理学知识，特别是势论知识，来自恩斯特·弗朗茨·诺伊曼。

罗兰的父亲于1871年2月2日去世，那一年罗兰回到匈牙利，被任命为布达佩斯大学的privatdozent，一年后晋升为理论物理学正教授。他现在继承了父亲的爵位，并于1872年成为匈牙利议会上院议员。1874年，他在所教的理论课题之外增加了实验物理学的教学，1878年前任讲席退休后，他成为实验物理学教授。罗兰于1876年7月29日与Gizella 约翰·霍瓦斯结婚，她是前匈牙利司法部长Boldizsár 霍瓦斯的女儿。Gizella是一位极有教养的贵族女孩，优秀的钢琴家，书法优美，精通法语。他们有两个女儿Ilona和Rolanda，她们在体育方面取得了显著成就，在匈牙利社会闻名。

罗兰在1876年至1886年间发表了关于表面张力的论文，这是他在柯尼斯堡师从恩斯特·弗朗茨·诺伊曼时开始感兴趣的主题。此时罗兰已设计出一种测量表面张力常数的仪器。在恩斯特·弗朗茨·诺伊曼的研讨会上展示他的想法使他得到了教授的赞扬，罗兰开始考虑该主题中的问题。他发现了罗兰的表面张力定律，该定律指出液体的分子表面能的温度系数与简单非缔合液体的性质无关。1886年后，他停止发表关于表面张力的论文，此后余生发表关于引力的论文。他发明了罗兰秤，并表明，在高度精确的程度上，引力质量和惯性质量是等价的。1891年，他在匈牙利Ság山上用他的扭秤进行了首次野外测量。他的兴趣转向引力的一个原因必定是，匈牙利自然科学学会于1881年要求进行测量，以确定匈牙利各地重力加速度的值[1]：-

罗兰在使用他的仪器方面的成就有三方面。通过发展罗兰秤的完整理论，他能够将其灵敏度推到如此程度，以至于花了数十年才设计出超过他精度的方法。应当指出，他所达到的高精度不仅归功于仪器的设计，还取决于他在使用仪器时表现出的无与伦比的技巧。另外两项成就包括清楚地认识到该秤的非常重要的应用：地球物理勘探以及引力质量与惯性质量的等价性。在这两种情况下，认识之后都伴随着紧张的工作来证明他的洞察力。

哥廷根大学宣布了一个悬赏题目，要求更精确地检验公认的事实：在真空中所有物体以相同的加速度下落。罗兰和他的研究团队确实以比以往所达到的高得多的精度检验了伽利略的这一古老论断。作为同一批实验的一部分，他还验证了引力质量与惯性质量在$10^{9}$分之5的精度内等价。

从1894年6月到1895年1月，罗兰在Sandor Wekerle的内阁中担任公共教育部长。他短暂任期的主要成就之一是创立罗兰学院，以改进匈牙利中学教师的培养。（不要以为罗兰是以自己的名字命名该学院的，它是以他父亲的名字命名的！）罗兰于1895年辞去这一政府职务，全身心投入布达佩斯大学的物理教学。

罗兰于1885年创立了匈牙利数学学会，后来物理学家也希望加入该学会，于是他于1891年创立了数学与物理学会。罗兰当选为该学会的第一任主席，并以下列话语宣布学会成立：-

通过我们在会议上的口头交流促进科学发展，并将一切值得专家关注的内容发表在期刊上：这一目标看起来并不比一个自我教育的学生团体的目标更高，然而如果我们给予它应有的关注，我们的工作就会有价值，就会完成一项重要任务。如果我们以奉献和认真的态度完成自我教育的任务，它还将带来这样的结果：未来科学的研究者和开拓者将从我们中间产生。我在此宣布数学与物理学会成立。

罗兰于1919年去世后，该学会更名为罗兰罗兰数学与物理学会。曾经位于布达佩斯的罗莎·培特帕兹马尼大学现在被称为罗兰大学。

1873年，罗兰成为匈牙利科学院的通讯院士，并于1883年当选为正式院士。1889年，他当选为匈牙利科学院主席。尽管这是一个三年任期，罗兰仍连续十六年连任该职位，直到1905年辞职。

罗兰有几项爱好。其中之一是登山，他喜欢在南蒂罗尔攀登。这不仅仅是一点消遣，因为罗兰很快就赢得了欧洲最著名登山家之一的声誉。他是第一个攀登多洛米蒂山脉若干山峰的人，他的名声如此之大，以至于那里有一座山峰以他的名字命名。他的女儿们长大后，从1896年左右开始陪同父亲进行了几次攀登。登山也与罗兰的另一项爱好相契合，即摄影。他在登山旅行中拍摄了许多照片，也在进行科学测量的野外考察中拍摄照片。由于在这种场合下是他拍照，这些照片往往显示罗兰队伍中的其他成员，而不是罗兰本人。

Loránd Eötvös is also known by the German version of Loránd, namely Roland. Had he only published in Hungarian, Eötvös would have achieved far less in the way of an international reputation so he published his most important results in German as well as Hungarian. To international scientists, therefore, he is known by the name which appeared on these German papers, namely Roland, Baron Eötvös. His full title is, however, far more grand: in Hungarian Vásárosnaményi Báro Eötvös Loránd; in English Roland, Baron Eötvös of Vásárosnaményi. Looking at a present day map of Hungary, Vásárosnaményi is close to its eastern border with Ukraine.

Loránd's mother was Agnes Rosty. His father was József, Baron Eötvös, a novelist, essayist, educator, and statesman, whose life and writings were devoted to the creation of a modern Hungarian literature and to the establishment of a modern democratic Hungary. He was a friend of Franz Liszt, the famous pianist and composer. At the time of Loránd's birth his father was minister of education in the revolutionary government of 1848, but after a disagreement with Lajos Kossuth, who headed the government, he resigned later in the year and went to Munich where he lived until 1851. Certainly Loránd grew up in a high ranking family and he received the benefits of a broad education. When he was young, Loránd's father employed Gusztáv Keleti, a painter who was the leader of the school of fine arts at that time, to tutor his son. Loránd rapidly showed talents in a whole range of artistic pursuits, and he became highly skilled at drawing, and wrote poetry. He sketched scenes from his travels in his notebook throughout his life.

At school Eötvös studied Hungarian, German, mathematics, history, geography, biology, mineralogy, and physics. Although mathematics and physics were particularly interesting to him, he was expected to follow the family tradition and study law as the route to a government position. When he entered the University of Budapest in 1865 he was following the family wishes and enrolled to take a law degree. Well, it is not quite true that he studied at the University of Budapest for at the time it was the University of Pest; only in 1872 did the town of Pest join with the town of Buda on the opposite bank of the Danube to form Budapest.

Eötvös was always more interested in mathematics and science than in law and while he studied law in courses at the university, he took private lessons in mathematics from Otto Petzval. József Eötvös, seeing that his son was fascinated by science, asked the professor of mineralogy at the University to teach the young Eötvös science. He also worked in the chemistry laboratory of Charles Than at the university and soon decided to give up law and concentrate completely on science.

He terminated his law studies in 1867 and went to study at Heidelberg where he was taught by Kirchhoff, Helmholtz and Bunsen. Clearly he was a typical student, for he received a caution from the police for singing too loudly on the street at night with his student friends! From Heidelberg he went to Königsberg and studied under Franz Neumann and Friedrich Richelot. He returned to Heidelberg and received a doctorate in 1870 with a thesis which studied problems of Fizeau on the relative motion of a light source. This was one of the first steps towards relativity theory. The years abroad had formed an extremely important period for Eötvös's development [1]:-

His professors profoundly influenced Eötvös's working habits. Kirchhoff taught him the importance of accurate measurements. Helmholtz liked to spend as much time as possible with his students and showed Eötvös the value of individual discussions. His knowledge of theoretical physics, and in particular of potential theory, came from Franz Neumann.

Eötvös's father died on 2 February 1871 and in that year Eötvös returned to Hungary and was appointed to the University of Budapest as a privatdozent for a year before being promoted to full professor of theoretical physics. He had now inherited his father's title and he became a member of the Upper House in the Hungarian Parliament in 1872. He added the teaching of experimental physics to the theoretical topics he taught in 1874 and he became professor of experimental physics in 1878 when the previous holder of the chair retired. Eötvös married Gizella Horváth, the daughter of the former Hungarian minister of justice Boldizsár Horváth, on 29 July 1876. Gizella was a highly cultured aristocratic girl, a fine pianist, with beautiful handwriting, having a good knowledge of French. They had two daughters Ilona and Rolanda who achieved significant success in sport, becoming famous in Hungarian society.

Eötvös published on surface tension between 1876 and 1886, a topic he had become interested in while studying with Franz Neumann in Königsberg. At this time Eötvös had devised an instrument to measure the constant of surface tension. Presenting his ideas in Franz Neumann's seminar had led to him receiving praise from his professor, and Eötvös began to consider problems in the topic. He discovered Eötvös's law of surface tension which states that the temperature coefficient of the molecular surface energy of a liquid is independent of the nature of simple unassociated liquids. After 1886 he ceased to publish on surface tension and from then on he published on gravitation for the rest of his life. He invented the Eötvös balance and showed that, to a high degree of accuracy, gravitational mass and inertial mass are equivalent. The first field measurements with his torsion balance were carried out on Ság Hill in Hungary in 1891. One reason why his interests moved towards gravitation must have been the fact that the Hungarian Society for Natural Sciences requested, in 1881, that measurements be made to ascertain the values for the acceleration due to gravity in different locations throughout Hungary [1]:-

The achievement of Eötvös in the use of his instrument are threefold. By developing the complete theory of the Eötvös balance, he was able to push its sensitivity to such a point that it took decades to devise methods for exceeding his precision. It is only proper to mention that the high degree of precision he achieved was not due solely to the design of the instrument but depended also on the unparalleled skill he displayed in using it. The other two accomplishments encompassed the clear recognition of the very important applications of the balance: geophysical exploration and the equivalence of gravitational and inertail mass. In both cases the recognition was followed by intense work proving his insight.

The University of Göttingen announced as a prize topic a request for improved accuracy in checking the accepted fact that all bodies fell with the same acceleration in a vacuum. Eötvös, and his team of researchers, did indeed check this old claim of Galileo with very much higher accuracy than had previously been achieved. He also verified, as part of the same experiments, that gravitational mass and inertial mass are equivalent to an accuracy of 5 parts in $10^{9}$.

From June 1894 to January 1895 Eötvös was the minister of public instruction in the Cabinet of Sandor Wekerle. One of the main achievements of his short period of office was the founding of the Eötvös Collegium to improve the teaching of Hungarian secondary school teachers. (Do not think Eötvös named the College after himself, rather it was named after his father!) Eötvös resigned this government post in 1895 to devote himself fully to teaching physics at the University of Budapest.

Eötvös founded the Hungarian Society for Mathematics in 1885 and after physicists also wished to be part of the Society, he founded the Mathematical and Physical Society in 1891. Eötvös was elected as the first president of the Society and declared it founded with the following words:-

To further the development of science by word of mouth at our meetings, and publish everything that is worth the attention of the experts in a journal: this goal does not seem more than the goal of a self-educating student circle, and still in case we give it the deserved attention, our work will have merit, it will fulfil an important task. If we carry out the task of self-education with dedication and seriousness, it will also have the result that in the future the researchers and developers of science will come from among us. I hereby declare the Mathematical and Physical Society founded.

After Eötvös died in 1919, the Society was renamed the Eötvös Loránd Mathematical and Physical Society. What was once the Péter Pázmány University in Budapest is now known as the Loránd Eötvös University.

In 1873 Eötvös became a corresponding member of the Hungarian Academy of Sciences, being elected as a full member in 1883. In 1889 he was elected President of the Hungarian Academy of Sciences. Although this was a three year term, Eötvös continued to be re-elected to the position for sixteen years until he resigned in 1905.

Eötvös had several hobbies. One was mountaineering and he loved climbing in the South Tirol. This was not simply a little recreation, for Eötvös soon gained the reputation as one of Europe's most famous mountaineers. He was the first to climb a number of peaks in the Dolomites and his fame was such that a peak there is named after him. After his daughters grew up they accompanied their father on several climbs from around 1896. Climbing also fitted in with another of Eötvös's hobbies, namely photography. He took many photographs while on mountaineering trips, but also took photographs while on field trips making scientific measurements. Since on such occasions he would take the photographs, they tend to show other members of Eötvös's party but not Eötvös himself.