Gerald Maurice Clemence

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Gerald Maurice Clemence (16 August 1908 – 22 November 1974) was an American

U.S. Nautical Almanac Office.[1]

Early life

Born on a farm near

nurse, in 1929.[1]

Mercury and Mars

After initial work in the Time Service Department, alongside

general theory of relativity.[1][3]

Clemence identified systematic errors in the predictions of

residuals showed a marked periodicity and Clemence concluded that the Fourier series on which the predictions were based was wrong. Clemence set out to derive a new series from scratch using the methods detailed by Hill and Peter Andreas Hansen in the nineteenth century. The calculations were carried out with "a lead pencil, large sheets of computing paper, [and] a hand-operated Millionaire desk calculator".[1] Though electronic calculators were available towards the end of the project, the calculations took twelve years.[4]

Nautical Almanac Office

Wallace John Eckert was appointed as director of the Nautical Almanac Office in 1940 and immediately imported his enthusiasm for using punched card machines for scientific calculation. Clemence was an early senior appointment to the new regime and soon saw the potential of electronic computation, using it initially on his Mars work but increasingly on the military work whose priority escalated following the entry of the U.S. into World War II.[1]

Clemence was appointed assistant director in 1942 and was joined on the staff by Paul Herget.[1] The pair worked on calculating mathematical tables and developed the optimum-interval technique to construct tables calculated at non-constant intervals and for which linear interpolation was everywhere legitimate.[5]

In 1945, Eckert left for the IBM-sponsored computing laboratory at Columbia University and Herget became director of the Cincinnati Observatory. Clemence was promoted to director of the Nautical Almanac Office, the post once held by his role-model Newcomb, and proved an able and energetic administrator.[1]

Research collaboration

In 1947, there began an intense period of cooperative research on celestial mechanics between Clemence's office, Eckert's group at Columbia and Yale University Observatory, under the direction of Dirk Brouwer, a former collaborator of Eckert's on punched cards.[1]

Later career

In 1958, Clemence was appointed first scientific director of the

time measurement, as well as collaborating on two text books.[1][6][7][8][9]

However, Clemence's passion for research ultimately led him to relinquish his managerial roles in 1962, and, in 1963 Brouwer found him a post at Yale. Here, Clemence continued his work on the perturbation theory of the Earth's orbit but it was interrupted, never to be completed, in 1966 when Brouwer's death demanded that Clemence take over the administration of the department.[1]

He died in Providence, Rhode Island on November 22, 1974, after an illness of several months.[1]

Personality

Clemence was reserved and dignified, conservative in manner and appearance. In writing he was concise and accurate. He was sincere and forthright with a code of ethics inherited from his parents. He was a family man, father of two sons, and always maintained contact with his three brothers and his sister. He was a keen, and self-taught, musician, accomplished at violin, piano and organ. He was also a keen railfan.[1]

Offices, awards and honors

References

  1. ^ a b c d e f g h i j k l m n o p q r s t Duncombe (2001)
  2. ^ "William Markowitz, 1907-1998". U.S. Naval Observatory. Department of the Navy. Archived from the original on 2016-05-10. Retrieved 2007-08-29.
  3. ^ Astronomical Papers of the American Ephemeris (1943)
  4. ^ Astronomical Papers of the American Ephemeris (1949)
  5. JSTOR 2002889
    .
  6. ^ Brouwer & Clemence (1961)
  7. ^ Woolard & Clemence (1966)
  8. doi:10.1063/1.3057799
    .
  9. doi:10.1016/0032-0633(67)90054-2
    .
  10. ISBN 978-3-540-00238-3
    .

Bibliography

External links
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