Ernest William Brown

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Ernest William Brown : biography

29 November 1866 – 22 July 1938

Later work

Wallace John Eckert already became an instructor at Columbia University while finishing his PhD under Brown. Eckert would improve the pace of astronomical calculation by automating them with digital computers. Brown retained his professorship at Yale until he retired in 1932. As well as continuing his work on the Moon, he also worked on the motion of the planets around the Sun. He co-wrote the book, Planetary Theory, with Clarence Shook, which contained a detailed exposition of resonance in planetary orbits and examined the special case of the Trojan asteroids.

Private life

Brown never married, and for most of his adult life lived with his younger unmarried sister, Mildred, who kept house for him. A capable pianist fond of music, he also played chess to a high standard. He loved travelling, hill walking, and detective stories.

A heavy smoker, Brown suffered from bronchial trouble for much of his life. He was afflicted by ill-health during most of the six years of his retirement, and died in New Haven, Connecticut in 1938.

Honours

Awards

  • Gold Medal of the Royal Astronomical Society (1907)
  • Bruce Medal (1920)
  • James Craig Watson Medal (1936)

Named after him

  • The crater Brown on the Moon
  • Asteroid 1643 Brown
  • Brown lunation number

Legacy

Brown’s Tables were adopted by nearly all of the national ephemerides in 1923 for their calculations of the Moon’s position, and continued to be used, eventually with some modification, until 1983. With the advent of digital computers, Brown’s original trigonometrical expressions, given in the introduction to his 1919 tables (and from which the tables had been compiled), began to be used for direct computation instead of the tables themselves. This also gained some improvement in precision, since the tables themselves had embodied some minor approximations, in a trade-off between accuracy and the amount of labor need for computations using the tables in those days of manual calculation. By mid-century, the difference between Universal and Ephemeris Time had been recognised and evaluated, and the troublesome empirical terms were also removed. Further adjustments to Brown’s theory were then also made in a later stage, arising from improved observational values of the fundamental astronomical constants used in the theory, and from re-working Brown’s original analytical expansions to gain more precise versions of the coefficients used in the theory.

It was only as recently as in the ephemerides for 1984 that Brown’s work was superseded: it was replaced by results gained from more modern observational data (including data from lunar laser ranging) and by altogether new computational methods for calculating the Moon’s ephemeris.