西奥多·冯·卡门Theodore von Kármán

西奥多·冯·卡门的父母是Helen Kohn和Mór 冯·卡门，前者来自一个波希米亚显赫家族，后者是一位杰出的哲学与教育学教授。冯·卡门在匈牙利语中的名字是von Skőllőskislaki 冯·卡门 Tódor（Tódor相当于冯·卡门，在匈牙利语中姓氏在名字之前）。冯·卡门在家中由他父亲以前的一名学生辅导，他的早期教育完全由他父亲主导。部分原因是Mór非常严格且强势，但也因为他是教育专家，在自己的儿子身上实践自己的理念。

冯·卡门的三个哥哥在他六岁时就意识到他是一个数学神童，因为他表现出非凡的心算大数能力。然而，Mór担心儿子会变成一个最终表演数学把戏的怪人，坚持让冯·卡门在几年内远离数学，要求他学习地理、历史和文学。冯·卡门九岁时进入布达佩斯的Minta 文理中学（Gymnasium）。他上这所学校绝没有以任何方式逃脱父亲的教育理论，因为这是一所按照他父亲教育最聪明孩子的理念建立的学校。

在冯·卡门于明塔中学完成学业的那一年，他获得了厄特沃什·罗兰奖，成为全匈牙利数学和科学方面最优秀的学生。这似乎是一个开启他数学研究的绝佳位置，而这正是他希望做的，但他的父亲对他另有打算，因此他被引导去布达佩斯的帕拉丁约瑟夫理工学院（后来成为布达佩斯技术大学）学习工程课程。冯·卡门的父亲在他开始工程课程的那一年精神崩溃，但这只使得冯·卡门完全不可能违背父亲的意愿。他于1902年从帕拉丁约瑟夫理工学院毕业，获得机械工程学位，并写了一篇关于The motion of a heavy rod supported on its rounded end by a horizontal plane的学位论文。有趣的是，尽管冯·卡门具有伟大的理论才能，他却不是一个熟练的实验者。虽然说冯·卡门的父亲把他推向了错误的方向有些苛刻，因为他后来取得了如此重大的进展，然而，他的才能始终在工程学的数学方面，而不是实践方面。

毕业后，冯·卡门必须服一年义务兵役，他在奥匈军队中担任炮兵学员。然后，在1903年，他被任命为帕拉丁约瑟夫理工学院的水力学助理，担任该职位三年。但冯·卡门在这些年里还担任了第二个职位，因为他担任一家德国机车制造商的顾问。他此时的研究是关于流体和结构压缩的，具有广泛的应用。特别重要的是他于1906年发表的关于The theory of buckling and compression tests on long slender columns的论文。

1906年，他获得了匈牙利科学院的两年奖学金，离开布达佩斯前往哥廷根学习，在那里他深受菲利克斯·克莱因、大卫·希尔伯特和路德维希·普朗特的影响。他于1908年3月短暂访问巴黎，在那里观看了一些开创性的飞行，这使他的兴趣转向将数学应用于航空学。他的研究现在涉及大型结构屈曲的数学模型，使用通过武器制造商克虏伯捐赠给哥廷根的大型液压机实验获得的数据。由于这项研究，冯·卡门于1908年获得博士学位，同年他接受了哥廷根的privatdocent职位。

随着哥廷根为齐柏林飞艇公司建造风洞，他对航空学的兴趣现在有了真正成为研究课题的机会。1911年，利用风洞的结果，他分析了流体流动中扁平体后面的交替双排涡旋，现在被称为冯·卡门涡街。这个名字来源于涡旋在双排两侧的位置交替的方式，其排列类似于街道两侧的路灯。然而，这并不是他这一时期唯一的研究课题，因为他还与马克斯·玻恩合作研究了振动原子。他们的工作研究了晶格动力学，其中他们将晶体的自由度与整个身体的正常振动模式等同起来。他们在这项重要研究中使用了三维傅里叶分析和周期性边界条件。

1912年，冯·卡门认为他在哥廷根的晋升前景不佳，因此他接受了斯洛伐克谢姆尼茨矿业学院（今天该镇称为班斯卡什佳夫尼察）的应用力学讲席。这很快被证明是一个判断错误，因为该学院设备不佳，也没有活跃的研究人员。他在那里教了一个学期后离开，回到哥廷根。1913年2月，冯·卡门接受了德国亚琛航空研究所所长的职位，以及亚琛技术大学的航空学和力学讲席。他开始在那里建立强大的研究团队，并对设备进行了重大改进，包括一个风洞。他开始进行飞机设计的理论工作，让学生和同事通过实验工作测试他的设计的有效性。

1914年第一次世界大战爆发，冯·卡门被征召入奥匈帝国军队服役，作为其战时工作的一部分，他从事军用飞机设计以及一种改进的直升机设计。1918年战争结束时，冯·卡门正在匈牙利工作，他留在那里试图改进当地的科学教学。然而，当时匈牙利的政治局势极其困难，该国于1918年11月16日宣布从奥地利独立。周边国家利用这一局势，塞尔维亚、捷克和罗马尼亚军队出动占领了该国部分地区。政治局势使任何教育改革都变得不可能，因此1919年冯·卡门回到了他在亚琛的先前职位。在德国主要飞机制造商的资助下，他开始了一项密集的研究计划，研究流体阻力、湍流和升力，所有这些都旨在改进飞机设计[1]：-

……几乎没有意识到他正在为一个新的德国空军，即第二次世界大战的德国空军（Luftwaffe）奠定基础。

冯·卡门于1926年应加州理工学院院长邀请访问美国，就风洞设计提供建议。到1928年，他每年在加州理工学院待六个月，在亚琛待六个月，然后1930年他被邀请担任加州理工学院航空实验室的全职主任。尽管他热爱亚琛，但德国的政治事件，特别是日益高涨的反犹主义，促使他接受了这一职位。他的母亲和妹妹随他去了加利福尼亚。冯·卡门从未结婚，他的母亲，后来是他的妹妹，为他照料家务。加州理工学院院长要求他把航空实验室[4]：-

……一个把美国航空工业吸引到南加州、并使该校在航空学领域取得全国领先地位的载体。

1933年，他创立了美国航空科学研究所，继续研究流体力学、湍流理论和超音速飞行。他研究数学在工程、飞机结构和土壤侵蚀中的应用。他的工作转向火箭研究，当德国在第二次世界大战期间被认为已研制出用于军事目的的火箭时，美国政府投入巨资进行火箭研究。1944年11月，这笔资金被用于在加州理工学院建立喷气推进实验室，由冯·卡门担任主任。该实验室后来对太空计划作出了重大贡献。

1949年，他辞去了两个主任职位，成为加州理工学院荣休教授。他仍然非常积极地向美国空军和北约提供建议，并在国际航空学会议上发挥了重要作用。

冯·卡门因其杰出贡献获得了许多荣誉。他于1946年获得美国功绩勋章，1948年获得富兰克林金奖，并于1963年成为首位获得国家科学奖章的人。他还获得了来自法国、梵蒂冈、德国、希腊、英国、西班牙和荷兰的荣誉。

关于他的性格，[2]中描述道：-

……一位令人愉快而机智的伙伴，对广泛的朋友圈忠诚。

在[1]中，他的贡献被总结如下：-

尽管他有许多公共活动，但他从未像许多发明家那样成为伟大的公众人物，也许是因为理论空气动力学对门外汉来说不是一个很容易进入的领域；尽管如此，他在该领域和火箭研究方面的工作帮助塑造了科学和政治历史。

人们有理由问，冯·卡门在就军事事务为许多国家提供建议后，如何看待自己的忠诚[1]：

冯·卡门对自己与军事当局的终身联系毫不掩饰，先是在奥匈帝国，然后在德国，最后是在美国和北约。他的观点是早期工程师的观点，即一旦他设法“提供对如果做了某些事情会发生什么的分析”，就可以被认为已经偿还了对社会的债务；他认为“科学家作为一个群体不应试图强迫甚至说服政府遵循他们的决定”。

Theodore von Kármán's parents were Helen Kohn, who was from a leading Bohemian family, and Mór Kármán who was a leading professor of philosophy and education. Theodore's name in Hungarian was von Skőllőskislaki Kármán Tódor (Tódor corresponds to Theodore and in Hungarian the family name precedes the given name). Theodore was tutored at home by a former student of his father and his early education was totally dominated by his father. Partly this was due to Mór being very strict and forceful, but also to the fact that he was an educational expert who practised his ideas on his own son.

Theodore's three elder brothers realised that he was a mathematical prodigy when he was six years old, for he demonstrated a remarkable ability to perform large mental calculations. Mór, however, fearing that his son would become a freak who ended up performing mathematical tricks, insisted that Theodore be kept away from mathematics for several years, requiring that he should study geography, history and literature. When he was nine years old Theodore entered the Minta Gymnasium in Budapest. He certainly did not escape his father's educational theories in any way by attending this school, for it was one which had been set up according to his father's ideas for educating the brightest children.

In the year that Kármán completed his education at the Minta Gymnasium he won the Eötvös Prize for the best student in mathematics and science in the whole of Hungary. It seemed a wonderful position from which to launch his mathematical studies which is precisely what he wished to do, but his father had other ideas for him and so he was steered towards an engineering course at the Palatine Joseph Polytechnic in Budapest (this later became the Technical University of Budapest). Kármán's father had a nervous breakdown in the year in which he began his engineering course but this only made it totally impossible for Kármán to go against his father's wishes. He graduated in 1902 from the Palatine Joseph Polytechnic with a degree in mechanical engineering, having written a dissertation on The motion of a heavy rod supported on its rounded end by a horizontal plane. It is interesting to note that despite Kármán's great theoretical talents, he was not a skilled experimenter. Although it is somewhat harsh to say that Kármán's father pushed him in the wrong direction since he went on to make such significant advances, nevertheless, his talents were always on the mathematical side of engineering and certainly not on the practical side.

After graduating Kármán had to undertake compulsory military service for one year and he served as an artillery cadet in the Austro-Hungarian army. Then, in 1903, he was appointed as an assistant in hydraulics at the Palatine Joseph Polytechnic, a position which he held for three years. But Kármán also held a second position during these years, for he acted as a consultant for a German locomotive manufacturer. His research at this time was on fluids and on the compression of structures which had wide ranging applications. Of particular importance was his paper published in 1906 on The theory of buckling and compression tests on long slender columns.

In 1906 he was awarded a two year fellowship from the Hungarian Academy of Sciences and he left Budapest to study at Göttingen, where he was greatly influenced by Klein, Hilbert and Prandtl. He made a short visit to Paris in March 1908 where he watched some pioneering aviation flights which turned his interest to applying mathematics to aeronautics. His research now involved mathematical models for the buckling of large structures, using data obtained through experiments with a large hydraulic press donated to Göttingen by the arms manufacturer Krupp. For this research Kármán was awarded his doctorate in 1908 and in the same year he accepted a position as privatdocent at Göttingen.

His interest in aeronautics now had a real chance to become a research topic with the construction at Göttingen of a wind tunnel for the Zeppelin airship company. In 1911, using results from the wind tunnel, he made an analysis of the alternating double row of vortices behind a flat body in a fluid flow which is now known as Kármán's Vortex Street. The name came from the way that the vortices alternated in position on the two sides of the double row in an arrangement similar to that of street lights on the two sides of a street. However, this was not his only research topic over this period, for he also collaborated with Max Born on a study of vibrating atoms. Their work studied lattice dynamics where they identified the degrees of freedom of a crystal with the normal modes of vibration of the whole body. They used three dimensional Fourier analysis and periodic boundary conditions in this important study.

In 1912 Kármán decided that his prospects of promotion were not good at Göttingen so he accepted the chair of applied mechanics at the Schemnitz mining college in Slovakia (today the town is called Banska Stiavnica). This quickly proved an error of judgement since the college was not well equipped nor did it have active researchers. He left after teaching there for one term and returned to Göttingen. In February 1913 Kármán accepted a post as director of the Aeronautical Institute at Aachen in Germany and also the chair of aeronautics and mechanics at the technical university in Aachen. He began to build a strong research team there as well as making major improvements to the equipment which included a wind tunnel. He began theoretical work on aircraft design, having students and colleagues test the effectiveness of his designs with experimental work.

World War I broke out in 1914 and Kármán was called up for military service in the Austro-Hungarian army, and as part of his war work he worked on the design of military aircraft and an improved design for a helicopter. When the war ended in 1918 Kármán was working in Hungary and he remained there trying to bring in improvements to the teaching of sciences there. The political situation in Hungary at this time, however, was extremely difficult with the country declaring independence from Austria on 16 November 1918. Surrounding countries took advantage of the situation and Serb, Czech, and Romanian troops moved to take over parts of the country. The political situation made any educational reforms out of the question, so in 1919 Kármán returned to his previous positions in Aachen. With financial assistance from the leading German manufacturers of aircraft, he began an intense programme of studying the resistance of fluids, turbulence and lift, all leading to better aircraft design [1]:-

... little realising that he was laying the foundations of a new German air force, the Luftwaffe of World War II.

Kármán visited the USA in 1926, at the invitation of the head of the California Institute of Technology, to advise on the design of a wind tunnel. By 1928 he was spending six months each year at Caltech and six months at Aachen, then in 1930 he was asked to be the full-time director of the Aeronautical Laboratory at California Institute of Technology. Despite his love for Aachen, the political events in Germany and in particular the rising anti-Semitism, persuaded him to accept. His mother and younger sister went to California with him. Kármán never married and his mother, then sister, looked after his home for him. The head of Caltech asked him to make the Aeronautical Laboratory [4]:-

... a vehicle to draw the U.S. aviation industry to Southern California and to bring to the campus national pre-eminence in aeronautics.

In 1933 he founded the U.S. Institute of Aeronautical Sciences continuing his research on fluid mechanics, turbulence theory and supersonic flight. He studied applications of mathematics to engineering, aircraft structures and soil erosion. His work turned towards research on rockets and, when Germany was seen to have developed rockets for military purposes during World War II, the United States Government put large sums of money into rocket research. In November 1944 the funding was used to set up the Jet Propulsion Laboratory at Caltech with Kármán as director. This laboratory later made major contributions to the space programme.

In 1949 he resigned his two positions of director and became professor emeritus at Caltech. He was still very active in giving advice to the U.S. airforce and NATO and played a major role in international conferences on aeronautics.

Kármán received many honours for his outstanding contributions. He received the United States Medal for Merit in 1946, the Franklin Gold Medal in 1948, and was the first to be awarded the National Medal for Science in 1963. He also received honours from France, the Vatican, Germany, Greece, the United Kingdom, Spain and the Netherlands.

As to his character, he is described in [2] as:-

... a delightful and witty companion, and loyal to a wide circle of friends.

In [1] his contributions are summed up as follows:-

Despite his many public activities, he never became a great public figure in the way of many inventors, perhaps because theoretical aerodynamics is not a very accessible field to the layman; nevertheless, his work in that field and in rocket research has helped shape both scientific and political history.

It would be reasonable to ask how Kármán saw his loyalties having advised many countries on military matters [1]:-

Kármán remained unabashed about his lifelong association with military authorities, first in Austro-Hungary, then in Germany, and finally in the United States and NATO. His viewpoint was that of an engineer of an earlier era who may be considered to have discharged his debt to society once he has contrived to "provide an analysis of what would happen if certain things were done"; he thought that "scientists as a group should not try to force or even persuade the government to follow their decisions".