克里斯蒂安·多普勒Christian Dopplerr

克里斯蒂安·多普勒的家族是石匠，自1674年起在奥地利萨尔茨堡拥有一家成功的企业。繁荣的生意使他们在萨尔茨堡的Hannibal Platz[现名Makart Platz]靠近河边建造了一座精美的房子。多普勒出生在这座家族住宅中，当然，家族传统本会让他长大接管石匠生意。然而他的健康从来不是很好，而且相当虚弱，所以他无法遵循家族传统。

多普勒在萨尔茨堡上小学，然后在林茨上中学。他的父母不确定他的学术潜力，咨询了萨尔茨堡中学的数学教授，教授建议多普勒应该在维也纳理工学院学习数学。理工学院成立于1815年，所以当多普勒于1822年开始在那里学习时，它仍然是一个新成立的机构。他在数学和其他学科上表现出色，并于1825年毕业。此后，他回到萨尔茨堡，在萨尔茨堡中学听哲学讲座，然后前往维也纳大学学习高等数学、力学和天文学。

1829年在维也纳大学完成学业后，多普勒被任命为该校高等数学与力学教授A Burg的助手。在担任Burg助手的四年间，他发表了四篇数学论文，其中第一篇是A contribution to the theory of parallels。这个助手职位只是临时性的，而多普勒比大多数其他人年长，在30岁时开始寻求永久职位。在[12]中，Seidlerova解释了当时奥地利的申请流程：-

从1825年起，奥地利大学和理工学院的所有空缺教授职位均通过公开竞争填补。这实际上意味着入学考试，其中题目是确定的……君主国各地学校的申请人必须以书面形式作答，这可能长达十二小时。考试的一部分还包括在指定委员会面前就任意主题进行简短的试用讲座。密封的答卷连同讲座评估随后被送往宣布竞争的学校。

最终决定由维也纳的委员会做出，但申请人仅根据其教学能力被选拔，任何更高知识水平的迹象都会被视为对候选人不利。多普勒参加了多次这类竞争，既有学校职位也有大学职位。他申请了林茨、萨尔茨堡、戈里齐亚和卢布尔雅那的学校，以及维也纳理工学院的高等数学讲席，并于1833年3月23日申请布拉格技术中学的算术、代数、理论几何和会计学教授职位。

在此期间，多普勒不得不谋生，他在一家棉纺厂担任了18个月的簿记员。这对多普勒来说是一段悲伤和极度困难的时期，他决定放弃不平等的斗争并移民到美国并不奇怪。他开始出售自己的财产，并拜访了慕尼黑的美国领事以做出必要的安排。然而，当他接近做出最终决定时，他收到了布拉格技术中学的职位邀请。任命过程花了很长时间才得出结论，多普勒于1835年3月上任，几乎正好是在参加竞争两年后。

多普勒雄心勃勃，在技术学校教授初等数学并不太合他的心意。他尝试申请布拉格理工学院的高等数学教授职位，但没有成功。然而，在1836-38年间，他能够每周在理工学院教授四小时高等数学。这带来了额外的收入，他肯定需要这些收入，因为他于1836年结婚。

然而，多普勒确实又获得了一次在理工学院任职的机会，1837年底，实用几何和初等数学的教授职位空缺。多普勒承担了该职位的职责，但事情并不那么简单。尽管他正在履行这些职责，但该职位的竞争于1839年10月3日举行。多普勒不必参加竞争，但竞争竟然举行这一事实伤害了他。他于1841年3月正式被任命到该职位。

多普勒在理工学院的教学并不轻松。Seidlerova在12中写道：-

考试压力很大。口试和笔试的条件都必须提前向地方委员会报告，该委员会还提名考试专员。例如，1843年1月和2月，多普勒必须在17天内对256名学生进行算术和代数的笔试和口试。考试每天至少需要六小时。同年6月和7月，同样数量的学生参加了“理论几何”的考试，考试为期十二天。此外，在7月和8月，必须在八天内对145名学生进行大地测量学考试。……1847年7月，多普勒口试了526名学生的数学和289名学生的测量学。

到1844年，多普勒一直不佳的健康在压力下崩溃了。他不得不放弃教学并请求病假。他得到了伯纳德·波尔查诺的支持，后者写道[14]：-

很难相信奥地利在这个人身上拥有多么富有成果的天才。我已写信给……许多能够为科学拯救多普勒、不让他死在枷锁下的人。不幸的是，我担心最坏的情况。

多普勒的学生抱怨他考试过于严厉，使情况变得更糟。多普勒受到调查和训斥，而学生被允许重考。多普勒认为自己完全无辜，并要求撤销训斥。最终，训斥在1844年底被勉强撤销，但多普勒直到1846年才恢复到足以履行职责。

在布拉格度过如此艰难的时期后，多普勒想要离开就不足为奇了，他获得了班斯卡什佳夫尼察矿业与林业科学院的数学、物理学和力学讲席教授职位。Stoll写道[14]：-

当多普勒离开布拉格前往班斯卡什佳夫尼察时，他并未料到在这座城市的停留会如此短暂。动荡的1848年震动了君主国的各个部分，革命在布拉格、维也纳和布达佩斯爆发。由于政治动乱，班斯卡什佳夫尼察的局势变得复杂，多普勒再次寻求避难。

他现在已是一位有一定重要性的人物，因此搬迁变得不那么困难。他被任命到维也纳理工学院，随后于1850年1月17日被任命为维也纳大学新物理研究所的第一任所长。多普勒达到了他职业生涯的高峰。

是什么品质使多普勒从早年的挣扎经历中走到这一重要职位？看来并不是他卓越的数学才能，因为尽管他以数学家的身份为业，但在数学研究方面他始终未能达到最高水平。事实上，他对数学的掌握可能比这还要差，因为他写了一本初等教科书Arithmetic and algebra，于1843年在布拉格出版。Seidlerova在[12]中描述这部著作时写道：-

多普勒的阐述方式非常不幸，表明在数学的基本问题上，他比同时代的杰出人物摸索得更多。

然而，尽管如此，多普勒内心确实有天才。这是一种伯纳德·波尔查诺从一开始就看到的天才。伯纳德·波尔查诺审阅了多普勒于1837年提交给皇家波希米亚科学学会的第一篇论文。在推荐多普勒关于应用分析的论文发表后，伯纳德·波尔查诺对多普勒本人作了评论。这份报告日期为布拉格1839年9月25日，内容如下[14]：-

多普勒先生已经通过他在数学和物理学领域发表的众多著作，向科学界展示了他非常有前途的能力。迄今为止他发表的著作所引发的期望，在与他本人结识后会成倍增长。你不仅会惊讶于这样一位年轻的科学家能够在许多知识领域产生如此多极其有趣且富有成果的想法，而且你还会极其愉快地确信，这种非凡的精神力量与和蔼的性格、真诚而不做作的决心以及对科学和真理的纯粹热爱结合在一起……

因此，伯纳德·波尔查诺本人作为一位伟大的数学创新者，能够看到多普勒身上的天才。然而并非每个人都能看到这一点。Kulik在多普勒于布拉格理工学院工作期间担任布拉格查理大学的数学教授，[14]：-

……对多普勒的独创性或他直觉式的思维方式并不太理解。

伯纳德·波尔查诺于1842年搬到布拉格，成为皇家波希米亚科学学会数学分会的秘书。当时他与多普勒有更密切的接触，伯纳德·波尔查诺在1844年写道[14]：-

多普勒教授在数周内用他的想法激发了我，一个比一个更精彩。我必须日夜思考它们。

然而在伯纳德·波尔查诺写下这段话的两年前，多普勒已经向皇家波希米亚学会提交了他最著名的精彩想法。1842年5月25日，多普勒提交了论文On the coloured light of the double stars and certain other stars of the heavens。会议记录对多普勒的演讲作了如下报道[11]：-

多普勒先生谈到了双星及天空中其他一些恒星彩色光的一种奇妙现象。他通过构建一种新的普遍理论来寻求这一显著现象的解释，该理论本身将詹姆斯·布拉德利的理论作为一个组成部分包含在内。

该论文首次提出了多普勒原理，它将光源的频率与其相对于观察者的速度联系起来。多普勒用几行推导出了这一原理，分别将光和声视为以太和物质中的纵波。多普勒关于光是纵波的观点是错误的。事实上，奥古斯丁·菲涅耳已经发表了他的理论，即光是横波，但是，尽管多普勒读过奥古斯丁·菲涅耳的著作，他并不接受。然而，这个错误实际上并不影响多普勒原理的结果。多普勒在试图通过应用于双星颜色来说明他的理论时也错了。尽管多普勒说他的原理会改变双星的颜色，取决于哪颗星正在接近或远离地球，这是正确的，但效应太小，不足以显著。

然而，多普勒在他的论文中做出了一个非凡的预测：-

几乎可以肯定的是，在不久的将来，这将为天文学家提供一种受欢迎的手段，以确定这类恒星的运动和距离，由于它们离我们不可测量的距离以及由此产生的视差角很小，直到此刻几乎没有人希望进行这样的测量和确定。

尽管用当时的仪器无法观察到颜色的变化，但声音的情况则相当不同。早在1845年，就进行了实验，让火车上的音乐家演奏乐器，其他受过训练的音乐家记录下火车接近和远离他们时的表观音符。1846年，多普勒发表了他的原理的一个更好的版本，其中他同时考虑了光源的运动和观察者的运动。

当然，并非每个人都立即被多普勒的理论说服。他最激烈的反对者是约瑟夫·佩兹瓦尔，此时已是维也纳大学的数学教授。他们的争论基于一种误解，从某种意义上说，双方都是正确的，但他们看不到他们争论的是不同的事情。

多普勒的其他著作都无法与他在多普勒原理方面的出版物的重要性相提并论。他确实发表了关于电和磁、磁偏角随时间变化的文章，以及几篇关于光学和天文学主题的出版物。他的头脑不断涌现新想法，因此他发明了许多仪器，特别是光学仪器，并改进了现有的仪器。他的大多数想法都相当具有革命性，他无疑是一位非常有独创性的思想家，但不利的一面是，大多数想法在实践中根本行不通。然而，人们常常可以在那里看到未来某些重要发现的萌芽，尽管多普勒提出的想法基本上是不正确的。

尽管有伯纳德·波尔查诺的大力支持以及他与该学会的良好关系，多普勒在成为皇家波希米亚学会会员方面仍遇到了一些困难。1837年，当他审阅多普勒提交给学会的第一篇论文时，伯纳德·波尔查诺在其报告中请求选举多普勒为学会会员。此事未获处理，但在次年，多普勒再次被提名，但在投票中未当选。

1840年6月28日，多普勒在一次7票赞成、5票反对的接近投票后，被选为皇家波希米亚学会的准会员。看起来，在1842年的论文之后，他获得了更多的支持，因为他在1843年11月5日以9票赞成、仅1票反对被选为该学会的正式会员。1847年，他被选为该学会的副书记，并成为该学会的领导人之一，根据伯纳德·波尔查诺的话[11]：-

……对科学与真理的纯粹热爱，它高高超越于狭隘的党派精神以及自负的顽固不化。

1848年多普勒获得的其它荣誉包括当选为维也纳帝国科学院的正式成员，以及布拉格大学授予的名誉博士学位。

多普勒作为维也纳大学物理研究所第一任所长的时期很短暂。他于1850年1月17日由帝国法令任命。他的健康状况继续恶化，出现严重的胸部问题，1852年11月，他前往威尼斯，希望更温暖的气候能带来一些改善。然而，事与愿违，到1853年3月，显然他正在迅速衰弱。多普勒的妻子在整个婚姻期间给予他坚定的支持，她与他们的三个儿子和两个女儿留在维也纳等待他归来，但在意识到他的生命即将结束时，她前往威尼斯，在多普勒去世时陪伴在他身边。

Christian Doppler's family were stonemason's who had a successful business in Salzburg, Austria from 1674. The prospering business led to the building of a fine house in the Hannibal Platz [now named Makart Platz] in Salzburg, near to the river. Christian Doppler was born in this family house and, of course, the family tradition would have had him grow up to take over the stonemason's business. However his health was never very good and he was quite frail so he could not follow in the family tradition.

Doppler attended primary school in Salzburg and then attended secondary school in Linz. His parents were unsure of his academic potential and consulted the professor of mathematics at the Salzburg Lyceum who recommended that Doppler should study mathematics at the Vienna Polytechnic Institute. The Polytechnic Institute had only been founded in 1815, so it was still a new establishment when Doppler began his studies there in 1822. He excelled in his mathematical and other studies and graduated in 1825. After this he returned to Salzburg, attended philosophy lectures at the Salzburg Lyceum, then went to the University of Vienna where he studied higher mathematics, mechanics and astronomy.

At the end of his studies at the University of Vienna in 1829, Doppler was appointed as assistant to the professor of higher mathematics and mechanics at the University, Professor A Burg. He published four mathematics papers during his four years as Burg's assistant, his first being A contribution to the theory of parallels. This assistantship was only a temporary post and Doppler, rather older than most others, began to seek a permanent post at the age of 30. In [12] Seidlerova explains how applications worked at that time in Austria:-

From 1825 all vacant professorships at Austrian universities and polytechnics were filled by public competition. It actually meant admission examination, where the questions were determined ... The applicants at various schools of the monarchy had to answer them in written form, which could take up to twelve hours. Part of the examination was also a short probationary lecture on an arbitrary topic in front of the appointed commission. The sealed answers, together with an evaluation of the lecture, were then sent to the school where the competition had been announced.

The final decisions were taken by the commission in Vienna but the applicants were only selected on their teaching ability, any sign of higher levels of knowledge would be treated as telling against the candidate. Doppler submitted himself to a number of these competitions, both for school and university places. He applied to schools in Linz, Salzburg, Gorizia and Ljubljana and for the chair of higher mathematics at Vienna Polytechnic and on 23 March 1833 for the professorship of arithmetic, algebra, theoretical geometry and accountancy at the Technical Secondary School in Prague.

While this was going on Doppler had to earn his living and he spent 18 months as a bookkeeper at a cotton spinning factory. This was a period of sadness and great difficulty for Doppler and it is not surprising that he decided to give up the unequal struggle and emigrate to America. He began to sell his possessions and visited the American Consul in Munich to make the necessary arrangements. However, when he was close to making the final decision he received an offer of the post at the Technical Secondary School in Prague. It had taken a long time for the process of appointing to reach its conclusion and Doppler took up his post in March 1835, almost exactly two years after entering the competition.

Doppler was ambitious and teaching elementary mathematics at the Technical School was not greatly to his liking. He tried for a post of professor of higher mathematics at the Polytechnic in Prague but without success. However, during 1836-38 he was able to teach higher mathematics for four hours a week at the Polytechnic. This brought in extra money which he certainly needed since he married in 1836.

Doppler did get another chance of a post at the Polytechnic, however, and at the end of 1837 the professorship in practical geometry and elementary mathematics became vacant. Doppler assumed the duties of the post but things were not that straightforward. Despite the fact that he was carrying out the duties, a competition for the post was held on 3 October 1839. Doppler did not have to take part in the competition but was hurt by the fact that it was held at all. He was formally appointed to the post in March 1841.

Doppler did not have an easy time teaching at the Polytechnic. Seidlerova writes in [12]:-

The examinations were very stressful. The terms of both oral and written exams had to be reported in advance to the Land Committee which also nominated the examination commissioner. For example, in January and February 1843 Doppler had to examine 256 students in 17 days, both in writing and orally, in arithmetic and algebra. The examinations took a minimum of six hours daily. The same number of students sat for the examination in "theoretical geometry" in June and July of the same year in a twelve day examination. Additionally in July and August it was necessary to examine 145 students in geodesy in eight days. ... In July 1847 Doppler orally examined 526 students in mathematics and 289 in geodesy.

By 1844 Doppler's health, always less than good, failed under the strain. He had to give up teaching and requested sick leave. He had support from Bolzano who wrote [14]:-

It is hard to believe how fruitful a genius Austria has in this man. I have written to ... many people who can save Doppler for science and not let him die under the yoke. Unfortunately I fear the worst.

The situation was made worse by Doppler's students complaining that he was too harsh in his examining. Doppler was investigated and reprimanded while the students were allowed to retake their examinations. Doppler considered himself totally innocent and demanded that the reprimand be withdrawn. Eventually the reprimand was reluctantly withdrawn by the end of 1844 but Doppler was not well enough to return to his duties until 1846.

With such a difficult time in Prague, it is no surprise that Doppler wanted to move and he was offered the professorship of mathematics, physics and mechanics at the Academy of Mines and Forests in Banska Stiavnica. Stoll writes [14]:-

When Doppler left Prague for Banska Stiavnica, he did not suspect that his stay in this city would be so short. The stormy year 1848 shook all parts of the monarchy and revolution broke out in Prague, Vienna and Budapest. Due to political unrest the situation in Banska Stiavnica became complicated and Doppler was once again seeking refuge.

He was now a figure of some importance so a move was now able to be made with less difficulty. He was appointed to Vienna Polytechnic, then on 17 January 1850 he was appointed as the first director of the new Institute of Physics at Vienna University. Doppler had reached the high point of his career.

What qualities had carried Doppler through the struggles of his early experiences to this important position? It was not, it seems, his great mathematical abilities, for despite his career as a mathematician he was always short of the topmost level when it came to mathematical research. In fact his grasp of mathematics may have been even less good than this for he wrote an elementary text Arithmetic and algebra published in Prague in 1843. Seidlerova, describing this work in [12] writes:-

Doppler's explanations were conducted in a very unfortunate way and demonstrated that in the basic questions of mathematics he groped more than his eminent contemporaries.

However, despite this Doppler did have genius within him. It was a genius that Bolzano saw from the very first. Bolzano reviewed the first paper which Doppler submitted to the Royal Bohemian Society of Sciences in 1837. After recommending Doppler's paper on applied analysis for publication, Bolzano commented about Doppler himself. Dated Prague 25 September 1839, the report reads [14]:-

Mr Doppler has already demonstrated his very promising abilities to the scientific community through his numerous published works in mathematics and physics. The expectations raised by his hitherto published works would multiply when one enters into personal acquaintance with him. You are not only struck by how many highly interesting and fruitful ideas, in many areas of knowledge, that so young a scientist is able to produce, but you also convince yourself with the greatest pleasure that this exceptional spiritual power combines with an amiable character, genuine unaffected determination and with that pure love of science and truth ...

So Bolzano, himself a great mathematical innovator, could see the genius in Doppler. Not everyone could see it however. Kulik, who was professor of mathematics at the Charles University of Prague while Doppler worked at the Polytechnic, [14]:-

... did not have much understanding of Doppler's originality or of his intuitive ways of thinking.

Bolzano moved to Prague in 1842 and became secretary to the mathematical section of the Royal Bohemian Society of Sciences. He was then in closer contact with Doppler and Bolzano wrote in 1844 [14]:-

Professor Doppler over several weeks has excited me with his ideas, the one more brilliant than the other. I must think about them day and night.

However two years before Bolzano wrote this, Doppler had presented his most famous brilliant idea to the Royal Bohemian Society. On the 25 May 1842 Doppler presented the paper On the coloured light of the double stars and certain other stars of the heavens. The minutes of the meeting reported on Doppler's lecture [11]:-

Mr Doppler talked about a wonderful phenomenon of the coloured light of the double stars and some other stars in the heavens. He sought the explanation of this striking phenomenon in formulating a new general theory, which included in itself as an integral part the theory of Bradley.

The paper presented for the first time the Doppler principle which relates the frequency of a source to its velocity relative to an observer. Doppler derived the principle in a few lines treating both light and sound as longitudinal waves in the ether and matter, respectively. Doppler was incorrect regarding light being a longitudinal wave. In fact Fresnel had already published his theory that light was a transverse wave but, although Doppler had read Fresnel's work, he did not accept it. However the error does not really affect the result of Doppler's principle. Doppler also was wrong when he tried to illustrate his theory with an application to the colours of double stars. Although Doppler was correct in saying that his principle would change the colours of double stars, depending on which star was approaching or receding from the Earth, the effect is too small to be significant.

Doppler does, however, make a remarkable prediction in his paper:-

It is almost to be accepted with certainty that this will in the not too distant future offer astronomers a welcome means to determine the movements and distances of such stars which, because of their unmeasurable distances from us and the consequent smallness of the parallactic angles, until this moment hardly presented the hope of such measurements and determinations.

Although changes in colours were impossible to observe with the instruments of the time, the situation with sound was rather different. As early as 1845 experiments were conducted with musicians on railway trains playing instruments and other trained musicians writing down the apparent note as the train approached them and receded from them. In 1846 Doppler published a better version of his principle where he considered both the motion of the source and the motion of the observer.

Not everyone of course was immedately convinced by Doppler's theory. His most vigorous opponent was Petzval, by this time professor of mathematics at the University of Vienna. Their dispute was based on a misunderstanding, in some sense both were correct but they could not see that they were arguing about different things.

No other work by Doppler came anywhere close in matching the importance of his publications on the Doppler principle. He did publish on electricity and magnetism, the variation of magnetic declination with time as well as several publications on optics and astronomical topics. His mind would continually come up with new ideas and so he was led to invent many instruments, particularly optical instruments, and improve existing ones. Most of his ideas are quite revolutionary, he was certainly a very original thinker, but on the down side most would just not work in practice. However one can often see the germ of some important future discovery there, even though the idea as presented by Doppler is basically incorrect.

Doppler had some difficulty becoming a member of the Royal Bohemian Society despite very strong support from Bolzano and his good relations with the Society. In 1837, when he reviewed the first paper that Doppler submitted to the Society, Bolzano requested in his report that Doppler be elected to the Society. This was not acted on but, in the following year, Doppler was proposed again and not elected in a ballot.

On 28 June 1840 Doppler was elected an associate member of the Royal Bohemian Society after a close ballot of 7 for and 5 against. It does appear that after his 1842 paper he gained more favour for he was elected as an ordinary member of the Society on 5 November 1843 with 9 votes in his favour and only one against. In 1847 he was elected deputy secretary of the Society and became one of the leaders of the Society who showed, according to Bolzano's words [11]:-

... pure love of science and truth which rises high above narrowminded party-spirit as well as conceited inflexibility.

Other honours which came Doppler's way in 1848 were election to ordinary membership of the Imperial Academy of Sciences in Vienna and an honorary doctorate from the University of Prague.

Doppler's time as the first Director of the Institute of Physics at Vienna University was a short one. He was appointed by Imperial Decree on 17 January 1850. His health continued to deteriorate with severe chest problems and, in November 1852, he travelled to Venice in the hope that the warmer climate would bring about some improvement. It was not to be, however, and by March 1853 it was clear that he was sinking fast. Doppler's wife, who had given him staunch support throughout their marriage, had remained in Vienna with their three sons and two daughters awaiting his return but, on realising that his end was near, she made the journey to Venice and was with Doppler when he died.