亚瑟·爱丁顿Arthur Eddington

亚瑟·爱丁顿的父亲爱丁顿 Henry Eddington曾在兰开夏郡的一所贵格会培训学院任教，后迁至肯德尔，成为斯特拉蒙盖特学校的校长。1884年，一场席卷全国的流行病中，他死于伤寒，当时他的儿子还不到两岁。爱丁顿的母亲萨拉·安·肖特来自达灵顿，与丈夫一样，也出身于贵格会家庭。爱丁顿 Henry Eddington去世后，她只得依靠微薄的收入抚养爱丁顿和他姐姐。全家迁往滨海韦斯顿，起初爱丁顿在家接受教育，之后在一所预备学校读了三年。

1893年，爱丁顿进入滨海韦斯顿的布赖梅林学校，该校主要招收寄宿生，但他并未寄宿，而是少数走读生之一。学校在有限的资源下提供了良好的教育，使爱丁顿在数学和英国文学方面表现出色。他在学校进步迅速，在数学上获得了很高的荣誉。然而，学校能够将爱丁顿带到的高度并不很高，他在数学上的良好基础未能达到微分和积分。

1898年，他获得了萨默塞特郡提供的每年60英镑、为期三年的奖学金（滨海韦斯顿现在属于埃文郡，但当时属于萨默塞特郡）。爱丁顿当时还不到十六岁，所以正式来说他太年轻，不能上大学。然而，这个问题很快就解决了，并没有使他推迟进入曼彻斯特欧文斯学院，他于1898年至1902年在该校就读。在学习的头一年，爱丁顿学习一般科目，随后三年主要学习物理。虽然学的是物理课程，爱丁顿还是去听数学课，并深受他的一位数学老师贺拉斯·兰姆的影响。当然，他家的经济状况意味着他们无法为他提供经济支持，但他出色的学业使他赢得了一些竞争激烈的奖学金，足以让他完成学业，并于1902年以一等荣誉获得理学学士学位。

1901年底，他获得了每年75英镑的自然科学奖学金，前往剑桥大学三一学院学习。1902年进入三一学院后，他于1903年3月获得了每年100英镑的数学奖学金，而不是自然科学奖学金。在三一学院，他师从埃德蒙·泰勒·惠特克、阿尔弗雷德·诺思·怀特海和欧内斯特·巴恩斯。1904年，他在数学荣誉学位考试中获得高级数学荣誉学位考试一等及格者（Wrangler），并于次年获得硕士学位。毕业后，他在卡文迪什实验室开始了一个关于热电子发射的研究项目，但似乎进展不太顺利，于是他放弃了该项目。1905年，他也开始了数学研究，但这并不比他在物理学方面的工作更成功，尽管许多年后，当他将这些早期数学研究思想应用于一个天文学问题时，他利用了这些想法。

1905年底之前，爱丁顿 被任命到格林尼治皇家天文台任职，从而转向天文学。天文学从小就是他感兴趣的话题，不到10岁时他就获借了一台3英寸望远镜，这进一步激发了他的兴趣。被任命填补皇家天文台的一个空缺后，他立即参与了一个自1900年以来一直在进行的研究项目，当时在一年内拍摄了爱神星的照片。爱丁顿 的第一项任务是完成这些照相观测的归算，以确定太阳视差的精确值。Plummer 在 [18] 中写道：——

他引入了分析两种星流的方法，而他在格林尼治的岁月里，对统计恒星天文学的主要兴趣集中在恒星的整体运动和分布上。

爱丁顿在1907年因一篇关于恒星自行的论文获得史密斯奖，并被授予三一学院研究员职位。乔治·达尔文是查尔斯·高尔顿·达尔文之子，剑桥大学普卢米安天文学教授，于1912年12月去世。1913年，爱丁顿被任命填补空缺的普卢米安天文学教授职位。事实上，剑桥有两个天文学讲席，另一个是劳恩迪安讲席。最初，普卢米安讲席涵盖该学科的实验方面，而劳恩迪安讲席涵盖理论方面。尽管多年来这种区分已变得有些模糊，但爱丁顿的任命无疑被视为实验天文学领域的任命。然而，劳恩迪安讲席的持有者于1913年底去世，1914年，爱丁顿成为剑桥天文台台长。这样一来，他实际上接管了剑桥理论天文学和实验天文学的责任。在被任命为剑桥天文台台长后不久，他当选为皇家学会会士。

在担任剑桥天文学研究领导角色后不久，第一次世界大战爆发。正如我们上面指出的，爱丁顿来自贵格会传统，作为一名良心拒服兵役者，他避免了积极的战争服务，并能够在1914-18年的战争年代继续在剑桥进行研究。然而，这对他来说并不是一个轻松的时期，在他担任剑桥讲席的开始阶段就给他带来了高度压力的时期。

爱丁顿对广义相对论理论做出了重要贡献。他对这个主题的兴趣始于1915年，当时他收到了阿尔伯特·爱因斯坦和威廉·德西特的论文，这些论文是通过皇家天文学会转给他的。他对这个理论产生了兴趣，特别是因为它为之前注意到但未解释的水星近日点进动提供了解释。他在1916年的英国协会会议上讲授了相对论，并在1918年为物理学会撰写了一篇关于该主题的重要报告。

次年，爱丁顿率领一支日食远征队前往西非的普林西比岛。其目的是验证相对论所预言的靠近太阳的光线弯曲。当时，这种对天空中靠近太阳的恒星的观测只能在日全食期间进行。他于1919年3月从英格兰启航，到5月中旬已在普林西比岛架设好仪器。日食预计在5月29日下午两点发生，但那天早晨有一场暴风雨，伴有大雨。爱丁顿写道（例如见[6]）：-

雨在中午前后停了，大约1点30分……我们开始瞥见太阳。我们不得不凭信念进行拍摄。我没有看到日食，因为忙于更换底片，只瞥了一眼确认它已经开始，另一次在半途看看有多少云。我们拍了十六张照片。它们都很好地拍到了太阳，显示出非常显著的日珥；但云干扰了恒星图像。最后几张照片显示了一些图像，我希望它们能给我们所需的东西……

他留在普林西比岛冲洗照片，并试图测量恒星位置的偏差。云使底片质量很差，难以测量。6月3日，他在笔记本中记录道：-

……我测量的一张底片给出的结果与阿尔伯特·爱因斯坦一致。

非洲远征的结果首次证实了阿尔伯特·爱因斯坦的理论，即引力会使光线在经过大质量恒星附近时弯曲。爱丁顿模仿奥马尔·海亚姆的Rubaiyat写道（例如见[6]）：-

哦，让智者去核对我们的尺度
至少有一件事是确定的，光有重量
一件事是确定的，其余皆可争论
光线，当靠近太阳时，不走直线。

爱丁顿在剑桥讲授相对论，对该主题作了优美的数学处理。他以这些讲座为基础写成了他的书Mathematical Theory of Relativity，该书于1923年出版。阿尔伯特·爱因斯坦说这部著作是：-

……以任何语言写就的该主题的最佳表述。

除了在相对论方面的工作，爱丁顿还在恒星的内部结构方面做了重要工作。他发现了恒星的质量-光度关系，计算了氢的丰度，并提出了一个理论来解释造父变星的脉动。他在这方面的早期研究包含在重要著作The Internal Constitution of Stars（1926）中。爱丁顿与詹姆斯·琼斯就恒星中能量产生的机制长期争论。他写道——当然这是正确的——关于产生能量的过程：-

……也许最简单的假说……是可能存在一种缓慢的物质湮灭过程。

然而，詹姆斯·琼斯倾向于能量是收缩之结果的理论。当然这并非完全错误，因为恒星形成时，在核反应开始之前，它最初会在收缩产生的能量下升温，然后为恒星一生的大部分时间提供能量来源。

爱丁顿的许多书是哲学著作，如The Nature of the Physical World（1928）、New Pathways of Science（1935）和The Philosophy of Physical Science（1939）。爱丁顿关于一门学科历史之重要性的相当不寻常的观点在这些著作中显露出来。他认为，熟悉一门学科的历史会妨碍对该学科的创造性研究。本档案的作者们在这个问题上不得不对爱丁顿表示强烈反对！

爱丁顿对自然界的基本常数着迷，并得出了一些令人惊讶的数值巧合，其中大部分发表在他于Fundamental Theory（1946年）去世后的一本书中，该书由埃德蒙·泰勒·惠特克准备出版。他在那本书中写道，他的目标是确定不同物理系统大小之间的关系。Ronan写道[20]：-

爱丁顿，尽管可能是一位头脑冷静的数学家和脚踏实地的天文学家，但他的天性中却有着神秘的一面，他生命的最后几年致力于构建一个庞大的物理宇宙的相对论综合，一座建筑，其中砖块是亚原子和观察者的天文证据，而灰浆是它们之间潜在的数学关系。

在[9]中，Kilmister深入探讨了导致爱丁顿在Fundamental Theory中提出的理论的思想，这些理论试图统一量子力学和广义相对论。Kilmister解释了爱丁顿如何认为认识论是物理学的基础，物理定律和物理常数是观察条件的后果。正是保罗·狄拉克1928年关于电子波动方程的论文首次使爱丁顿走上了寻求统一量子力学和广义相对论方法的道路。Kilmister解释了保罗·狄拉克对旋量的使用如何使爱丁顿感到惊讶，并导致他研究保罗·狄拉克代数的推广。他在代数方面的工作，即给出自然的对称描述，也在[21]中进行了考察。

爱丁顿于1930年被封为爵士，并于1938年获得功绩勋章。他还获得了许多其他荣誉，包括太平洋天文学会（1923年）、Royal Astronomical Society（1924年）、华盛顿国家科学院（1924年）、法国天文学会（1928年）和皇家学会（1928年）颁发的金质奖章。除了当选为皇家学会外，他还当选为爱丁堡皇家学会、Royal Irish Academy、National Academy of Sciences、Russian Academy of Sciences、Berlin Academy of Sciences以及其他许多机构的成员。1926年，他应邀在伦敦皇家学会作贝克里安讲座，当时他讲授的是Diffuse matter in interstellar space。

Plummer在[18]中写道：-

他作为数学物理学家的卓越装备使他受益匪浅……大胆的想象力与对可观察特征的非凡知识相结合。……爱丁顿感到自己被召唤去驶向未知的海洋，即使冒着犯错的风险也要冒险，而先驱者的回报也降临到他身上。……简单和谦逊是他的突出特点……

爱丁顿的成就在[3]中总结如下：-

他是一位天赋异禀的天文学家，其独创的理论与数学分析能力将这门科学向前推进了一大步；他是一位杰出的物理学与天文学阐释者，能够以最简洁、最引人入胜的语言传达最艰深的概念；他还是一位能向哲学家阐明最新科学发现之意义的出色诠释者。

Arthur Eddington's father, Arthur Henry Eddington, taught at a Quaker training college in Lancashire before moving to Kendal to become headmaster of Stramongate School. He died of typhoid in an epidemic which swept the country in 1884 before his son was two years old. Arthur Eddington's mother, Sarah Ann Shout, came from Darlington and, like her husband, was also from a Quaker family. On Arthur Henry Eddington's death she was left to bring up Arthur and his older sister with relatively little income. The family moved to Weston-super-Mare where at first Arthur was educated at home before spending three years at a preparatory school.

In 1893 Arthur entered Brymelyn School in Weston-super-Mare which was mainly for boarders but he did not board at the school, being one of a small number of day pupils. The school provided a good education within the limited resources available to it and allowed Arthur to excel in mathematics and English literature. His progress through the school was rapid and he earned high distinction in mathematics. The level to which the school was able to take Arthur was, however, not very advanced and his good grounding in mathematics stopped short of reaching the differential and integral calculus.

In 1898 he was awarded a scholarship of £60 a year for three years by Somerset County (Weston-super-Mare is now in Avon but it was at that time in Somerset). Eddington had not reached sixteen years of age at the time, and so officially he was too young to enter university. It was a problem which was solved quickly, however, and did not cause him to delay his entry to Owens College, Manchester which he attended from 1898 to 1902. In his first year of study Eddington took general subjects before spending the next three years studying mainly physics. Although on a physics course, Eddington attended the mathematics lectures, being greatly influenced by one of his mathematics teachers, Horace Lamb. Of course the financial position of his family meant that they were not able to provide him with financial support but his outstanding academic work allowed him to win a number of highly competitive scholarships to provide enough money to let him complete his B.Sc. course with First Class Honours in 1902.

He was awarded a Natural Science scholarship of £75 a year to study at Trinity College, Cambridge, near the end of 1901. Entering Trinity in 1902 he received, in March 1903, a Mathematics Scholarship of £100 a year instead of the Natural Science scholarship. At Trinity he was taught by E T Whittaker, A N Whitehead and E W Barnes. He became Senior Wrangler in the Mathematical Tripos in 1904 and graduated with a M.A. in the following year. After graduating, he began a research project in the Cavendish Laboratory on thermionic emission but it appears not to have gone too well and he gave up the project. He began research in mathematics, also in 1905, but this was no more successful than his work in physics although he was to make use of the ideas many years later when he applied these early research ideas in mathematics to an astronomy problem.

Before the end of 1905 Eddington had made the move to astronomy with his appointment to a post at the Royal Observatory at Greenwich. Astronomy had been a topic of interest to him from an early age and he had been given a loan of a 3 inch telescope when less than 10 years old which had heightened his interest. On being appointed to fill a vacancy at the Royal Observatory he was immediately involved with a research project which had been underway since 1900 when photographic plates of Eros had been taken over the period of a year. Eddington's first task was to complete the reduction of these photographic observations to determine an accurate value for the solar parallax. Plummer writes in [18]:-

He had introduced his method of analysis of two star-drifts, and his prevailing interest in statistical stellar astronomy was concentrated on the systematic motions and distribution of the stars throughout his Greenwich years.

Eddington was a Smith's prize winner for an essay on the proper motions of stars in 1907, and he was awarded a Trinity College Fellowship. George Darwin, a son of Charles Darwin and Plumian professor of astronomy at Cambridge, died in December 1912. In 1913 Eddington was appointed to fill the vacant position of Plumian Professor of Astronomy. There were in fact two chairs of astronomy at Cambridge, the other being the Lowndean chair. Originally the Plumian chair covered the experimental side of the subject while the Lowndean chair covered the theoretical side. Although this distinction had become somewhat blurred over the years the appointment of Eddington was certainly seen as an appointment in experimental astronomy. However, the holder of the Lowndean chair died towards the end of 1913 and, in 1914, Eddington became director of the Cambridge Observatory. In doing so he effectively took over responsibility for both theoretical and experimental astronomy at Cambridge. Shortly after his appointment as director of the Cambridge Observatory he was elected a Fellow of the Royal Society.

Shortly after taking up his role of leading astronomy research at Cambridge, World War I broke out. As we noted above Eddington came from a Quaker tradition and, as a conscientious objector, he avoided active war service and was able to continue his research at Cambridge during the war years of 1914-18. This was, however, not an easy time for him giving him a highly stressful period right at the beginning of his tenure of the Cambridge chair.

Eddington made important contributions to the theory of general relativity. His interest in this topic started in 1915 when he received papers by Einstein and by de Sitter which came to him via the Royal Astronomical Society. He became interested in this theory, particularly since it provided an explanation for the previously noticed, but unexplained, advance of the perihelion of Mercury. He lectured on relativity at the British Association meeting in 1916 and produced a major report on the topic for the Physical Society in 1918.

In the following year Eddington led an eclipse expedition to Principe Island in West Africa. Its aim was to verify the bending of light passing close to the sun which was predicted by relativity theory. At that time such observations of stars close to the sun in the sky could only be made during a total eclipse. He sailed from England in March 1919 and by mid-May had his instruments set up on Principe Island. The eclipse was due to occur at two o'clock in the afternoon of 29 May but that morning there was a storm with heavy rain. Eddington wrote (see for example [6]):-

The rain stopped about noon and about 1.30 ... we began to get a glimpse of the sun. We had to carry out our photographs in faith. I did not see the eclipse, being too busy changing plates, except for one glance to make sure that it had begun and another half-way through to see how much cloud there was. We took sixteen photographs. They are all good of the sun, showing a very remarkable prominence; but the cloud has interfered with the star images. The last few photographs show a few images which I hope will give us what we need ...

He remained on Principe Island to develop the photographs and to try to measure the deviation in the stellar positions. The cloud made the plates of poor quality and hard to measure. On 3 June he recorded in his notebook:-

... one plate I measured gave a result agreeing with Einstein.

The results from the Africa expedition provided the first confirmation of Einstein's theory that gravity will bend the path of light when it passes near a massive star. Eddington wrote, in a parody of the Rubaiyat of Omar Khayyam (see for example [6]):-

Oh leave the Wise our measures to collate
One thing at least is certain, light has weight
One thing is certain and the rest debate
Light rays, when near the Sun, do not go straight.

Eddington lectured on relativity at Cambridge, giving a beautiful mathematical treatment of the topic. He used these lectures as a basis for his book Mathematical Theory of Relativity which was published in 1923. Einstein said that this work was:-

... the finest presentation of the subject in any language.

In addition to his work in relativity theory Eddington also did important work on the internal structure of stars. He discovered the mass-luminosity relationship for stars, he calculated the abundance of hydrogen, and he produced a theory to explain the pulsation of Cepheid variable stars. His early research on this is contained in the important work The Internal Constitution of Stars (1926). Eddington had a long running argument with James Jeans over the mechanism by which energy was created in stars. He wrote, correctly of course, that as to the process of generating energy:-

... probably the simplest hypothesis ... is that there may be a slow process of annihilation of matter.

Jeans, however, favoured the theory that the energy was the result of contraction. Of course this is not entirely wrong since a star when it forms will initially heat up under the energy generated by contraction before nuclear reactions begin and then provide the energy source for most of the star's life.

Among Eddington's many books were philosophical works such as The Nature of the Physical World (1928), New Pathways of Science (1935) and The Philosophy of Physical Science (1939). Eddington's rather unusual view of the importance of the history of a subject comes over in these works. He believed that familiarity with the history of a subject was a hindrance to creative research in that subject. The authors of this archive would have to register their strong disagreement with Eddington on this issue!

Eddington had a fascination with the fundamental constants of nature and produced some surprising numerical coincidences most of which were published after his death in Fundamental Theory (1946), a book prepared for publication by Whittaker. He writes in that book that his aim was to determine the relation between the sizes of different physical systems. Ronan writes [20]:-

Eddington, hard-headed mathematician and down-to-earth astronomer though he might be, possessed a mystical side to his nature and the last years of his life were spent in an attempt to construct a huge relativistic synthesis of the physical universe, an edifice in which the bricks would be subatomic and astronomical evidence of the observer and the mortar the underlying mathematical relationships between them.

In [9] Kilmister delves deeply into the ideas which led Eddington to the theories he put forward in Fundamental Theory in attempting to unite quantum mechanics and general relativity. Kilmister explains how Eddington considered that epistemology is at the basis of physics, that physical laws and physical constants are the consequences of the condition of observation. It was Dirac's 1928 paper on the wave equation of the electron which had first set Eddington on the path of seeking ways to unify quantum mechanics and general relativity. Kilmister explains how Dirac's use of spinors had surprised Eddington and led him to study a generalisation of the Dirac algebra. His work on algebras which would give a symmetrical description of nature is also examined in [21].

Eddington was knighted in 1930 and received the Order of Merit in 1938. He received many other honours including gold medals from the Astronomical Society of the Pacific (1923), the Royal Astronomical Society (1924), The National Academy of Washington (1924), the French Astronomical Society (1928), and the Royal Society (1928). In addition to election to the Royal Society, he was elected to the Royal Society of Edinburgh, the Royal Irish Academy, the National Academy of Sciences, the Russian Academy of Sciences, the Berlin Academy of Sciences and many others. He was invited to give the Bakerian Lecture of the Royal Society of London in 1926 when he lectured on Diffuse matter in interstellar space.

Plummer writes in [18]:-

To his splendid equipment as a mathematical physicist he owed much ... A bold imagination was coupled with an exceptional knowledge of those features which are accessible to observation. ... To launch out into unknown seas, to be venturesome even at the risk of error, Eddington felt himself called, and the reward of the pioneer came to him. ... Simplicity and modesty were his outstanding characteristics ...

Eddington's achievements are summed up in [3] as follows:-

He was a gifted astronomer whose original theories and powers of mathematical analysis took his science a long way forward; he was a brilliant expositor of physics and astronomy, able to communicate the most difficult conceptions in the simplest and most fascinating language; and he was an able interpreter to philosophers of the significance of the latest scientific discoveries.