Dr. Wallace Eckert Dies at 69;
Tracked Moon with Computer
By WILLIAM M. FREEMAN
Dr. Wallace J. Eckert, a former executive of the
International Business Machines Corporation and professor of celestial
mechanics at Columbia University, died yesterday in a nursing home in
Englewood, N.J. He was 69 years old and lived at 216 Leonia Avenue, Leonia,
Dr. Eckert had undergone brain surgery last May in the Columbia-Presbyterian Medical Center.
Dr. Eckert was noted for his contributions to the scientific application of electronic computers and to the theory of the motion of the moon. He also made pioneering advances in developing punch-card computing systems in the nineteen-thirties and developed a control unit for directing punch-card computations.
In 1945, Dr. Eckert became head of I.B.M.'s Pure Science Department and director of the Watson Scientific Computing Laboratory at Columbia. This laboratory, the outgrowth of the T.J. Watson Astronomical Computing Bureau, was operated by I.B.M. at Columbia to provide computational facilities for all fields of science.
The Watson computing center was the first major training center for scientific computation. The center has graduated more than 1,000 scientists, who use machines in such fields as astronomy, physics, crystallography, geology, chemistry, statistics and optics.
Dr. Eckert was largely responsible for the over-all design in 1949 of the SSEC, the Selective Sequence Electronic Calculator, which was the first large-memory, general-purpose computer.
Dr. Eckert plotted the positions of the moon for the period 1952-71 in his "Improved Lunar Ephemeris," which was a standard work used by astronomers. Its precision stemmed from the use of digital computers and numerical analysis techniques.
The scientist's figuring of the moon's orbit was separated into several separate computations, the
most important of which, termed "the main problem,"
describes the motion of the moon caused by the gravitational pull of the sun,
the earth, and the moon itself.
Once this computation has been completed, the pull of other planets, the distribution of mass within the earth and moon and the effects of relativity are added as small corrections.
The heart of the computing problem is to determine the frequency and amplitude of each oscillation. By adding together all these perturbations the motion of the moon caused by gravitational forces can be predicted for a considerable time into the future.
In the year 1940 to 1945 Dr. Eckert, as director of the United States Nautical Almanac Office, introduced machine methods of computing, table printing, proofreading and data-handling for the Almanac Office and other areas of the Naval Observatory.
He designed and developed in 1940 the American Air Almanac, a volume that has greatly influenced air and sea navigation and, with minor, modifications, is still in international use.
He joined Columbia's Department of Astronomy as an assistant instructor, serving from 1926 to 1940. During this period he earned a Ph.D. from Yale in 1931.
In the early thirties he developed what was believed to be the first automatic computing center for scientific research. With advanced punch-card techniques his machines were able to perform calculations in celestial mechanics to reduce observational data and to record stellar statistics.
In 1948, Dr. Eckert received the James Craig Watson Medal, the oldest award of the National Academy of Sciences, for outstanding astronomical research.
He retired from IBM in 1967 and since then continued his work on computation of the moon's orbit.
He leaves his wife, the former Penelope Applegate, and two children, John and Alice.