欧内斯特·威廉·布朗Ernest William Brown

布朗的父母是Emma Martin和欧内斯特·威廉·布朗。布朗当了几年农民，后来改行成为木材商。布朗是他父母孩子中的第二个，有一个姐姐。他在赫里福德郡Trotteridge的一所学校接受教育，之后进入赫尔的赫尔与东赖丁学院。

他在这所学院表现出极大潜力，并于1884年进入剑桥大学基督学院。布朗于1887年获得学士学位，当时他在数学荣誉学位考试中排名第六数学荣誉学位考试一等及格者（Wrangler）（意味着他是数学一等荣誉学位学生中第六名）。他于1891年获得剑桥大学硕士学位。同年，他离开英国前往美国。在此之前，他于1889年加入了皇家天文学会，而在他离开英国的那一年，他的第一篇论文由该学会发表，内容是关于月球理论。

布朗于1891年被任命为宾夕法尼亚州哈弗福德学院的数学讲师，随后于1893年晋升为应用数学正教授。1907年，他被任命为耶鲁大学数学教授，并一直担任该职位直到1932年退休。然而，他的暑假几乎都是在英国剑桥大学度过的。

在去美国之前，布朗在剑桥工作时读过乔治·威廉·希尔的Researches in the lunar theory（1878），并发表了自己关于该理论的想法。当布朗到达美国时，西蒙·纽康正在编制行星运动表，而西蒙·纽康已说服乔治·威廉·希尔通过研究木星和土星的运动来帮助他。由于这意味着乔治·威廉·希尔不再研究月球运动，布朗认为该领域无人占据，于是自己开始在这一领域工作。

他于1896年出版了An Introductory Treatise on the Lunar Theory，随后基于乔治·威廉·希尔的思想开始了一种新的月球轨道理论。他的伟大著作于1897年至1908年间分五部分发表在Memoirs of the Royal Astronomical Society上。

经过30年的工作，布朗于1919年发表了他的月球表Tables of the Motion of the Moon。然而，月球顽固地拒绝遵循数学家和它计算出的路径，尽管试图考虑所有合理的影响，仍然存在理论未预测到的运动波动[2]：-

布朗从观测方面提出了一种方法，并提议比以往更大程度地利用恒星掩星的观测来绘制月球的路径并改进理论。

1926年，布朗发表了一篇论文，将这种波动归因于地球自转周期的不规则变化，这一观点后来被证明是正确的。

布朗不仅对月球轨道理论做出了巨大贡献，还研究了行星运动。他与C A Shook合著的关于这一主题的书Planetary Theory于1933年出版。

布朗因其工作获得了许多奖项。他在31岁时就被选为皇家学会的会士。1907年，他因Researches in the lunar theory获得了皇家天文学会的金奖，1914年获得了皇家学会的皇家奖章。1937年，他获得了国家科学院的沃森奖章。

他还是美国数学会的活跃成员，并于1914年至1916年担任其主席。他的生活方式，也许是他对天文学兴趣的结果，在[8]中被描述如下：-

他习惯早睡，因此会在凌晨三点到五点之间醒来。在喝下保温瓶里的浓咖啡提神后，他不离开床就开始工作，抽很多香烟。他的严肃科学工作因此是在他九点起床吃早餐之前完成的。

在[2]中，他被描述如下：-

他举止优雅，性格谦逊友好，在偶尔访问祖国时，是英国天文学家们欢迎的客人。

Ernest Brown's parents were Emma Martin and William Brown. William worked as a farmer for some years before changing jobs and becoming a lumber merchant. Ernest was the second of his parents' children, having one older sister. He was educated at a school in Trotteridge, Herefordshire, following which he attended Hull and East Riding College in Hull.

He showed great promise at this College and, in 1884, he entered Christ's College, Cambridge. Brown received his B.A. in 1887 when he was ranked Sixth Wrangler in the Mathematical Tripos (meaning he was the sixth best student with First Class honours in mathematics). He was awarded an M.A. from the University of Cambridge in 1891. In that year he left England for the United States. Before this, in 1889, he had joined the Royal Astronomical Society and in the year he left England his first paper was published by that Society on lunar theory.

Brown was appointed as an instructor in mathematics at Haverford College, Pennsylvania in 1891 then, in 1893, he was promoted to full Professor of Applied Mathematics. In 1907 he was appointed Professor of Mathematics at Yale University, a post he held until he retired in 1932. However his summers were almost all spent back in England at the University of Cambridge.

While he had worked in Cambridge, before going to the United States, Brown had read Hill's Researches in the lunar theory (1878) and published his own ideas on that theory. Newcomb was constructing tables of planetary motion when Brown arrived in the United States and Newcomb had persuaded Hill to help him out by working on the motion of Jupiter and Saturn. As this meant that Hill was no longer working on the motion of the Moon, Brown thought that the field was open and so began work himself in that area.

He published An Introductory Treatise on the Lunar Theory in 1896, then embarked on a new theory of the orbit of the Moon based on Hill's ideas. His great work appeared in five parts in the Memoirs of the Royal Astronomical Society between 1897 and 1908.

After 30 years of work, Brown published his lunar tables Tables of the Motion of the Moon in 1919. However the Moon stubbornly refused to follow the path that mathematicians computed for it and, despite attempts to take all reasonable effects into account, there were still fluctuations in the motion not predicted by theory [2]:-

Brown proposed an attack from the observational side and proposed utilising the observation of occultations of stars to a larger extent than hitherto to map the moon's path and improve the theory.

In 1926 Brown published a paper in which he ascribed these fluctuation to irregular changes in the Earth's period of rotation which has subsequently proved correct.

Not only did Brown contribute greatly to the theory of the Moon's orbit but he also worked on planetary motion. His book on this topic, Planetary Theory, written jointly with C A Shook, appeared in 1933.

Brown received many awards for his work. He was elected a Fellow of the Royal Society at the early age of 31. He received the Gold Medal of the Royal Astronomical Society in 1907 for his Researches in the lunar theory, and the Royal Medal of the Royal Society in 1914. He received the Watson Medal of the National Academy of Sciences in 1937.

He was also an active member of the American Mathematical Society, serving as its president from 1914 to 1916. His life style, perhaps the consequence of his interest in astronomy, is described in [8] as follows:-

He was in the habit of going to bed early and as a consequence woke up between three and five o'clock in the morning. After having fortified himself with strong coffee from a thermos bottle he set to work without leaving his bed, smoking numerous cigarettes. His serious scientific work was thus done before he got up for breakfast at nine o'clock.

In [2] he is described as follows:-

Of elegant presence and of unassuming friendly character, he was a welcome guest to British astronomers on his occasional visits to his native country.