拉尔夫·福勒Ralph H. Fowler

拉尔夫·福勒是Howard Fowler和Frances Eva（曼彻斯特棉花商人George Dewhurst的女儿）的长子。他被描述为相当健壮，拥有响亮但和蔼的笑声。他显然从父亲那里继承了运动天赋，父亲是橄榄球和板球明星。他的父亲是牛津人，被召入律师界，但没有成为大律师，而是从商。

福勒的早期教育由家庭女教师在家中处理。十岁时，他考入Horris Hill的Evans预备学校，在那里他在田径方面表现出色，尤其是板球和足球（英式足球）。1902年，13岁时，福勒赢得了温切斯特公学的奖学金，在入学考试中排名第二（这显然让他恼火，尽管当时他生病了）。他在温切斯特度过了接下来的六年，成为Prefect of Hall（学校校长）并赢得了数学和自然科学方面的学校奖项。再一次，田径是福勒生活的主要焦点，尽管他在高尔夫方面取得了成功，但他被他的妹妹Dorothy击败，她是一位冠军高尔夫球手。

福勒在温切斯特的学术能力非凡。他的古典六年级导师Frank Carter认为，他本可以成为一名与他作为数学学者一样优秀的古典学者。但吸引他的是数学。他的数学能力与他和蔼的性格相匹配。在温切斯特，福勒结交了许多朋友。尽管他倾向于直言不讳，但他总是在事后弥补，这似乎对人们产生了影响，无论是在温切斯特还是后来，人们似乎都聚集在他周围。

他的家庭生活似乎同样平衡。人们常常可以看到他与父亲、姐姐和弟弟Christopher一起打高尔夫球。Fowler家的家庭生活显然相当幸福，福勒的父母“为了孩子们的教育尽可能完美，不惜一切，假期也安排得充实”[3]。在福勒于Winchester期间，他家从Essex搬到了Norfolk，定居在Weybourne，靠近Sheringham，Fowler一家常在那里打高尔夫球。稍后他们又搬到了Somerset的Burnham-on-Sea的Glebelands，但在此之前福勒还打了一阵板球，为Norfolk郡队效力了一段时间。

1906年12月，福勒赢得了剑桥大学三一学院的主要奖学金，并于1908年米迦勒学期前往三一学院。在三一学院，他攻读数学，于1909年完成了数学荣誉学位考试的第一部分，获得一等。1911年，他在荣誉学位考试第二部分中成为数学荣誉学位考试一等及格者（Wrangler）。1911年完成第二部分后获得学士学位，1915年获得硕士学位。1913年，他被授予数学Rayleigh奖。不用说，剑桥对福勒相当不错——或者更确切地说，福勒对剑桥相当不错。

完成学位后，福勒开始研究纯数学。他的娴熟和洞察力使他在1914年10月获得了三一学院的研究员职位。然而，第一次世界大战刚刚爆发，他获得了皇家海军炮兵队的委任。人们常常可以看到他在三一学院穿着长袍罩在军装卡其布上，这显然是一道不寻常的景象。战争倒不那么不寻常，它相当典型地带来了苦难。福勒也未能幸免。1917年，他在索姆河失去了弟弟Christopher，这对他打击很大。后来，他又以类似的方式失去了在Winchester的两位最好的朋友A D Gillespie和R H Hutchison。福勒本人在加里波利肩部受重伤。然而，这次受伤结果却喜忧参半，因为它使他结识了A V Hill，Cambridgeshires的上尉，国王学院的研究员（也是三一学院的前研究员）。因为正是Hill最终成为催化剂，将福勒的数学才能带入了物理学领域。

Hill与Horace Darwin（出自多产的Darwin家族，其中包括物理学家C G Darwin、弗朗西斯·高尔顿，以及最著名的Horace的父亲、进化论者查尔斯·高尔顿·达尔文）合作，发明了一种镜像系统，最初设计用于确定飞机的飞行路径，后来用于为防空炮瞄准德国齐柏林飞艇。福勒正好在他们开始实地测试该仪器时加入。随着有才华的年轻科学家加入这个小组，它被称为“Hill的强盗”，正是在这里，福勒建立了一些他最珍视的友谊，尤其是与爱德华·亚瑟·米尔恩的友谊，后者在福勒生前和死后都写了几篇文章和讣告。

福勒很快成为Hill的副手，在Whale岛的HMS Excellent实验部门工作。福勒作为助理主任，居住在Portsmouth，而Hill经常前往伦敦与上级沟通。Hill最终成为名誉少校，而福勒被任命为皇家海军炮兵上尉。福勒招募了一长串有能力的数学家加入这个小组，结合Hill的灵感，福勒的数学能力带领小组完成了许多重要工作。许多发表在期刊上，包括两篇现在经典的论文，发表在Philosophical Transactions of the Royal Society上，对英国和北美的弹道学领域产生了深远影响，尤其是在第二次世界大战中。

福勒显然不是“文书工作者”，他既积极参与实验，也从事繁重的论文写作。他在这一领域的工作特别使他考虑高海拔的风结构和温度结构，这可能成为他后来对热力学和统计力学兴趣的催化剂。由于他的弹道学工作，福勒于1918年被授予OBE。

1919年，福勒退役并回到三一学院，尽管后来在第二次世界大战期间他将在新成立的军械委员会中任职。正是在这时，福勒受到了刚被任命为卡文迪什教授的Lord Rutherford的影响。两人成为非常好的朋友，福勒最终于1920年被任命为学院数学讲师。在这里，他投身于各种数学问题，并最终开始转向数学物理中更近期的问题，包括各种气体动理论的工作，这再次将他引向热力学和统计力学。

1921年，福勒与艾琳结婚，她是Lord Rutherford的独生女，福勒在剑桥的好友和同事。在接下来的九年里，两人育有四个孩子，艾琳在最后一个孩子出生后不久去世。

1922年，福勒成为剑桥的学监，作为一名海军陆战队员，他非常适合这一职位，发现自己经常追赶本科生，有一次还因此受伤。也是在1922年，福勒开始了他最具开创性的工作。这最初是与C G达尔文（著名的达尔文家族的另一位成员）的合作。两人受到保罗·埃伦费斯特和Trkal工作的启发，开始研究能量分配问题。通过统计力学发展出一种研究物理化学的新技术后，两人，以及后来福勒独自，证明了Saha、费迪南德·冯·林德曼和西德尼·查普曼等人所做的一些公式和计算。1922-23年，福勒确立了高温电离解离公式的有效性。1923年初，福勒与爱德华·亚瑟·米尔恩一起，撰写了一篇关于恒星光谱、温度和压力的开创性著作。这项工作在20世纪20年代通过一系列论文继续，导致1923-24年获得剑桥大学约翰·柯西·亚当斯奖，并于1929年出版为开创性卷册Statistical Mechanics，其第二版删去了天体物理应用，于1936年出版。1939年，与E A古根海姆合著并出版了后续卷册Statistical Thermodynamics。

1926年标志着他最具开创性的个人论文的发表，该论文将气态简并态（服从量子统计，由保罗·狄拉克共同发现，而保罗·狄拉克是由福勒本人引入量子理论的）与白矮星联系起来。据传，他对自己没有同时将恩里科·费米-保罗·狄拉克统计应用于导体感到恼火，这项工作后来由阿诺·索末菲完成。

福勒的兴趣范围使他在接下来的二十年里持续工作，发表了关于光谱学、物理化学、现在称为凝聚态物理（或固态物理）以及材料磁性的论文。他最终在剑桥卡文迪什实验室任职，并于1932年当选为新设立的普卢默理论物理讲席。

他与岳父Lord Rutherford密切合作，研究了许多有趣的问题，并于1935年发表了关于晶体比热的贝克讲座，1934年发表了关于氢的重同位素的利弗西奇讲座。1925年，他当选为皇家学会会士，并于1933年成为温彻斯特的会士。1936年，他被授予皇家奖章之一，并于1938年被任命为国家物理实验室主任，尽管由于健康不佳未能就职。根据爱德华·亚瑟·米尔恩的说法，从第一次世界大战前的纯粹数学家到第二次世界大战时的物理学家、工程师和管理者的转变简直令人惊讶，这极大地证明了福勒在实践事务中的能力。

1938年，他因病无法就任国家实验室主任一职，于是选择留在剑桥担任普卢默讲席。1939年战争爆发时，他不顾健康状况，立即恢复了在军械委员会的工作，并最终被选为驻加拿大以及后来驻美国的科学联络人，这两个国家他曾通过访问多伦多以及在普林斯顿大学和威斯康星大学担任访问教授而熟悉。由于担任这一联络工作，他于1942年被授予爵士爵位。

战争后期他返回英国，据称一直在为军械委员会和海军部工作，直到1944年他过早去世前仅几周。

必须说，福勒爵士是一位杰出的物理学家。但也许他最广为人知的是他对别人的影响。事实上，在1922年至1939年间，福勒指导了不下十五位皇家学会会士和三位诺贝尔奖得主。在此期间他指导的总人数达到惊人的六十四人，这意味着他在任何时候平均都有十一名研究生。人们可能会认为，这不允许他与学生之间形成任何深度的关系。然而，事实远非如此。在福勒指导下学习的人对他怀有极大的钦佩。特别是，爱德华·亚瑟·米尔恩[1]尤其被这个人所吸引，他亲切地称他为“那种即使把摩托车卖给你，你仍然可以和他保持友好的人；不可能说得更多了”，并称他为“人中之王”[2]。

除了对他产生深远影响的爱德华·亚瑟·米尔恩之外，他还有机会影响亚瑟·爱丁顿爵士、苏布拉马尼扬·钱德拉塞卡、保罗·狄拉克、威廉·麦克雷爵士、贝尔塔·斯韦尔斯夫人等人，或是通过直接指导，或是通过合作间接影响。即使在个人生活中，他也与杰出人物有着密切的联系，他娶了Lord Rutherford的独生女艾琳，他是在剑桥卢瑟福的卡文迪什实验室认识她的。有时他的影响仅仅是因为他被这么多人所熟知。正是福勒最终在1923年将保罗保罗·狄拉克引入了蓬勃发展的量子理论领域，使保罗·狄拉克在1925年走到了最终发现的前沿。福勒还通过尼尔斯·玻尔让保罗·狄拉克和维尔纳·海森堡取得了联系。正如威廉·麦克雷爵士简单地说[3]：“他在正确的时间、正确的地点，是正确的人。”

福勒的影响深远，超越了剑桥的神圣殿堂，延伸到英国和外国的政府。他生活的这一方面再次部分是时机问题。在加里波利服役于皇家海军陆战队期间，他受了重伤。在康复期间，他遇到了A V Hill，后者在防空炮术方面的工作催生了“Hill's Brigands”，这是一群才华横溢的科学家，负责开发更好的瞄准德国齐柏林飞艇的技术。这项工作产生了关于旋转炮弹空气动力学的两篇经典论文，据爱德华·亚瑟·米尔恩称，这项工作对英国和北美的弹道学产生了巨大影响。这段经历也使福勒具有足够的影响力，能够在二十年后第二次世界大战中影响英国及其盟友的行动。

在后来的这场战争中，福勒担任英国与加拿大之间以及后来英国与美国之间的联络人。1942年他被授予爵士爵位，无疑部分是由于他在两次战争中对国家的英勇服务。

在职业生涯早期，获得学位之后，福勒开始研究某些二阶微分方程解的行为。他特别研究了Emden微分方程：$\Large\frac{1}{\xi^{2}\normalsize} \Large\frac{d}{d\xi}\normalsize (\xi^{2}\Large\frac{d\theta}{d\xi}\normalsize ) = -\theta^{n}$。亚瑟·爱丁顿爵士最初表明，利用上述方程并取$n = 3$，可以求出气态恒星的平衡态。由此他得到了恒星光度关于质量的公式。爱德华·亚瑟·米尔恩想知道如果恒星不具有这种特定的能量产生率会发生什么。他正确地推断出Emden方程必定有其他解。当爱德华·亚瑟·米尔恩向福勒透露他的想法时，福勒立即针对不同的$n$值和所有类型的边界解发展出了一个新的解。由此得到的通用方程，后来对恒星天体物理学产生了相当大的影响，其形式为：$\Large\frac{d }{d\xi}\normalsize (\xi^{\sum } \Large\frac{d\theta}{d\xi}\normalsize ) ± \xi^{\sigma'}\theta^{n} = 0$。这后来与他在白矮星退化态方面最具原创性的论文相关联。在这篇论文中，福勒表明白矮星的物质必定由服从恩里科·费米-保罗·狄拉克统计的气体组成——也就是说，它必定处于退化态。原子被如此剧烈地电离，以至于它们实际上没有电子。这些离子紧密堆积，留下自由电子形成退化气体，福勒将其描述为“像一个处于最低态的巨大分子”。后来发现，白矮星的平衡态由Emden方程的一个解来描述，该方程经福勒在上述方程中取$n = \large\frac{3}{2}\normalsize$推广而来。

福勒的天才在于他能够将严格的数学严谨性应用于各种物理问题。但也许他最大的特点是他结交朋友和熟人的能力，这体现在他众多的“粉丝”以及他在科学和政治上编织的影响网中。世界在如此年轻的时候就失去了这样一位伟人，确实令人遗憾。

Ralph Howard Fowler was the eldest son of Howard Fowler and Frances Eva (the daughter of George Dewhurst the Manchester cotton merchant). He was described as being quite athletic and possessing a loud, though affable, laugh. He apparently inherited his athleticism from his father who was a star at rugby and cricket. His father was an Oxford man who was called to the bar, but instead of becoming a barrister went into business.

Ralph's early education was handled at home by a governess. When he was ten he matriculated at Evans' preparatory school at Horris Hill where he excelled at athletics, in particular cricket and football (soccer). At the age of 13, in 1902, Ralph won a scholarship to Winchester College placing second in the entrance examination (which apparently annoyed him despite the fact that he was sick at the time). He spent the next six years at Winchester where he became Prefect of Hall (Head of School) and won school prizes in mathematics and natural science. Once again, athletics was a major focus of Ralph's life, though despite his success at golf, he was outdone by his sister Dorothy who was a champion golfer.

Ralph's academic ability was exceptional at Winchester. His classical sixth form master, Frank Carter, believed he could have been as good a classical scholar as he was a mathematical scholar. But it was mathematics that attracted him. And his ability at mathematics was matched by his affable character. At Winchester Ralph made numerous friends. Despite his penchant for speaking plainly, he always made up for it after and this seemed to have an affect on people who, both at Winchester and later, seemed to gather around him.

His family life appeared to be equally well-balanced. He could often be found golfing with his father, sister, and brother Christopher. Family life at the Fowlers was apparently quite happy and Ralph's parents "spared nothing that their children's education should be as perfect as possible, with well-occupied vacations" [3]. During Ralph's stay at Winchester his family moved from Essex to Norfolk, taking up residence in Weybourne, near Sheringham which was where the Fowlers golfed regularly. A bit later they moved on to Glebelands, Burnham-on-Sea, Somerset, but not before Ralph got in a bit of cricket, playing for Norfolk County for some time.

In December of 1906, Ralph won a Major Scholarship to Trinity College, Cambridge, and he left for Trinity during Michaelmas term 1908. At Trinity he read mathematics completing Part I of the Mathematical Tripos in 1909, taking a first class. In 1911 he became a wrangler in Part II of the Tripos. He received his BA degree in 1911 upon completion of Part II and received his MA in 1915. In 1913 he was awarded a Rayleigh Prize in Mathematics. Needless to say, Cambridge was quite good to Ralph - or, rather, Ralph was quite good to Cambridge.

After completion of his degree, Ralph took to researching pure mathematics. His adeptness and insight won him a Trinity Fellowship in October 1914. However, World War I had just broken out and he obtained a commission in the Royal Marine Artillery. He could often be seen at Trinity wearing his gown over his military khakis which was apparently quite an unusual site. The War was less unusual, being rather typical in handing out suffering. Ralph was not immune. In 1917 he lost his brother Christopher on the Somme which was quite a blow to him. Later he was to lose his two greatest friends at Winchester, A D Gillespie and R H Hutchison, in a similar manner. Ralph himself was severely wounded in the shoulder at Gallipoli. The wound turned out to be a bit of a mixed bag, however, as it caused him to be introduced to A V Hill, Captain in the Cambridgeshires, and a Fellow at King's College (and former Fellow at Trinity). For it was Hill who was ultimately the catalyst that brought Ralph's mathematical ability into the realm of physics.

Hill, in collaboration with Horace Darwin (of the ever-prolific Darwin family that included the physicist C G Darwin, Frances Galton, and the most famous of all, Horace's father, Charles Darwin, the evolutionist), had invented a mirrored system originally designed to determine the flight paths of aircraft and later used to target German zeppelins for anti-aircraft gunneries. Fowler came in just as they began to test the instrument in the field. As talented young scientists joined the group, it came to be known as "Hill's brigands" and it was here that Fowler made some of his most endearing friendships, not the least of which was E A Milne, who wrote several articles and obituaries on Fowler both before and after his death.

Fowler soon became Hill's second in command working with the Experimental Department of HMS Excellent on Whale Island. Fowler, being Assistant Director, was resident in Portsmouth while Hill traveled often to London often for commune with higher ranks. Hill eventually became a brevet Major while Fowler was made a Captain, RMA. Fowler recruited a long list of able mathematicians to join the group and, combined with Hill's inspirations, Fowler's mathematical ability led the group to a number of important works. Many were published in journals including two now classic papers that appeared in the Philosophical Transactions of the Royal Society that were to have a profound impact on the field of ballistics both in Britain and in North America, particularly in World War II.

Far from being a "paper-pusher", Fowler apparently was active in both the experiments as well as the laborious paper-writing. His work in this field led him, in particular, to consider wind structure and temperature structure at high altitudes which could have been the catalyst for his later interest in thermodynamics and statistical mechanics. For his ballistics work, Ralph was awarded the OBE in 1918.

In 1919 Fowler left the service and returned to Trinity, though he was to have a part in the newly formed Ordnance Board during the Second World War later on. This was when Fowler came under the influence of Lord Rutherford who had just been appointed Cavendish Professor. The two became very good friends and Fowler was eventually appointed College Lecturer in Mathematics in 1920. Here he jumped into a variety of mathematical problems and eventually began moving to more recent problems in mathematical physics including work on various kinetic theories of gases, again leading him toward thermodynamics and statistical mechanics.

In 1921, Ralph married Eileen, the only daughter of Lord Rutherford, Ralph's good friend and colleague at Cambridge. The two were to have four children in the following nine years with Eileen dying just after the birth of the last.

In 1922, Ralph became a Proctor at Cambridge which, being a Marine, he was well-suited for, finding himself chasing after undergraduates frequently and, on one occasion, injuring himself doing so. It was also in 1922 that Ralph began what would be his most seminal work. It began as a collaboration with C G Darwin (another of the famous Darwin clan). The two began working on the problem of the partition of energy, inspired by works of Ehrenfest and Trkal. Having developed a new technique for approaching physical chemistry through statistical mechanics, the two, and later Fowler alone, justified a number of formulae and calculations performed by the likes of Saha, Lindemann, and Chapman. In 1922-23, Ralph established the validity of the dissociation formula for high temperature ionization. In early 1923, Ralph along with E A Milne, wrote a seminal work on stellar spectra, temperatures, and pressures. This work continued in a series of papers through the 1920s leading to the Adams Prize of the University of Cambridge in 1923-24 and was published in 1929 as the seminal volume, Statistical Mechanics, which had a second edition, minus the astrophysical applications, published in 1936. In 1939 a successor volume, entitled Statistical Thermodynamics, was co-authored and published with E A Guggenheim.

1926 marked the publication of his most seminal individual paper which linked the gaseous degenerate state (obeying quantum statistics, co-discovered by P A M Dirac, who was introduced to quantum theory by Fowler himself) to white dwarf stars. It is rumored that he was annoyed that he did not, at the same time, apply Fermi-Dirac statistics to conductors, something later done by Sommerfeld.

Fowler's range of interests kept him going throughout the next two decades as he produced papers on spectroscopy, physical chemistry, what is now known as condensed matter physics (or solid state physics), and magnetism in materials. He eventually took up a post in the Cavendish Laboratory at Cambridge and, in 1932, he was elected to the newly created Plummer Chair of Theoretical Physics.

Working closely with his father-in-law, Lord Rutherford, he examined a number of interesting problems and delivered the 1935 Bakerian Lecture on specific heats of crystals and the 1934 Liversidge Lecture on the heavy isotope of hydrogen. In 1925 he was elected as a Fellow of the Royal Society and became a Fellow at Winchester in 1933. In 1936 he was awarded one of the Royal Medals and was appointed as Director of the National Physical Laboratory in 1938, though he was unable to take up the post due to ill health. According to Milne, the transformation from pure mathematician prior to World War I to physicist, engineer, and administrator by Word War II was nothing short of astonishing and a great tribute to Fowler's ability in practical matters.

In 1938, upon taking ill and not being able to take up the National Laboratory Directorship, he chose to remain at Cambridge in the Plummer Chair. In 1939 when war broke out, he immediately resumed his work with the Ordnance Board, despite his health, and was eventually chosen to become a scientific liaison to Canada and later the United States, two countries which he had formerly been familiar through visits to Toronto and visiting professorships at Princeton and the University of Wisconsin. For his work as this liaison, he was knighted in 1942.

He returned to Britain later in the war and was reportedly working for the Ordnance Board and the Admiralty up until just a few weeks prior to his very premature death in 1944.

It must be said that Sir Ralph Fowler was a brilliant physicist. But it may be for his influence upon others that he is best known. In fact, no less than fifteen Fellows of the Royal Society and three Nobel Laureates were supervised by Fowler between 1922 and 1939. The total number supervised during this time was a staggering sixty-four giving him an average of eleven research students at any given time. One might be led to believe that this did not allow for any depth of relationship to form between him and his students. However, this was far from the truth of the matter. Those who studied under Fowler had a tremendous admiration for him. In particular, E A Milne [1] was especially taken by the man whom he fondly referred to as "the kind of man you can still remain friendly with, even when he has sold you a motor-bike; it is not possible to say more" and whom he called a "prince amongst men" [2].

Aside from Milne, on whom he had a profound impact, he also had the opportunity of influencing the likes of Sir Arthur Eddington, Subramanian Chandrasekhar, Paul Dirac, Sir William McCrea, Lady Jeffreys and others either directly through supervision or indirectly through collaboration. Even in his personal life he was intimately connected with brilliant people having married Eileen, the only daughter of Lord Rutherford whom he met through Rutherford's Cavendish Laboratory at Cambridge. Sometimes his influence was simply the fact that he was known to so many people. It was Fowler who ultimately introduced Paul Dirac to the burgeoning field of quantum theory in 1923 leading Dirac to the forefront of its ultimate discovery in 1925. Fowler also put Dirac and Werner Heisenberg in touch with each other through Niels Bohr. As Sir William McCrea simply put it [3]: "he was the right man in the right place at the right time."

Fowler's influence was far-reaching, extending beyond the hallowed halls of Cambridge and into government, both British and foreign. This aspect of his life was once again partly a matter of timing. While serving in the Royal Marines during Gallipoli he was seriously wounded. During his recovery he met A V Hill whose work in anti-aircraft gunnery had spawned "Hill's Brigands," a group of talented scientists charged with developing better techniques for targeting German Zeppelins. This work led to two classic papers on the subject of the aerodynamics of spinning shells and, according to Milne, the work had a tremendous impact on ballistics both in Britain and North America. This experience also made Fowler influential enough to affect the actions of Britain and her allies twenty years later in the second World War.

During this later War, Fowler acted as a liaison between Britain and Canada and, later, Britain and the United States. In 1942 he was knighted, no doubt partly due to his heroic service to his country during both wars.

Early in his career, after receiving his degree, Fowler took to examining the behavior of the solutions to certain second-order differential equations. In particular, he studied Emden's differential equation:

Fowler's genius was in his ability to apply intense mathematical rigour to a variety of physical problems. But perhaps his greatest trait was his ability to make friends and acquaintances exemplified both by his numerous "fans" and the web of influences he wove both scientifically and politically. It is indeed a shame that the world lost such a great man at such a young age.