Sidney Bertram
Sidney Bertram | |
|---|---|
 | |
| Born | Sydney Abramovitch July 7, 1913 Winnipeg, Manitoba, Canada |
| Died | July 30, 2012 Scotts Valley, California, United States |
| Residence | Scotts Valley, CA, United States |
| Nationality | USA |
| Alma mater | California Institute of Technology; Ohio State University |
| Known for | PPI scanning sonar; automated photogrammetry (UNAMACE); Electromagnetism |
| Scientific career | |
| Fields | Electrical engineering, Physics |
| Institutions | University of California Division of War Research; Boeing; Ohio State University; Ramo-Wooldridge (Bunker-Ramo Corporation); Cal Poly San Luis Obispo |
Sidney Bertram (born Sydney Abramovitch; July 7, 1913 – July 30, 2012) was a Canadian-born American electrical engineer and physicist. Over a career of more than fifty years he worked on wartime sonar, guidance systems, and automated photogrammetry, and later taught electricity and magnetism at Cal Poly San Luis Obispo. In retirement he pursued an independent classical approach to electromagnetics and relativity.
Biography
Bertram was born Sydney Abramovitch in Winnipeg, Manitoba, Canada; the family name was changed after they moved to California in 1923. He completed a vocational electrical course in high school, graduating in February 1930, then enrolled in the semi-professional electrical engineering program at Los Angeles City College, from which he received an Associate of Arts degree in 1932.
From 1933 to 1936 he taught at the Radio Institute of California in Los Angeles, working first as a laboratory instructor and later teaching radio theory. He re-entered the California Institute of Technology and earned a B.S. in electrical engineering, with honors, in 1938. After a year with a small geophysics company, he undertook graduate study at Ohio State University, receiving an M.S. in 1941; his thesis, "Calculation of Axially Symmetric Fields," was published in two papers cited in the literature on electron optics. He completed a Ph.D. in physics at Ohio State University in 1951 while teaching at its Wright Field Graduate Center.
In 1942 Bertram joined the University of California Division of War Research at San Diego, where he converted an experimental FM fire-control sonar into a PPI scanning sonar. In the summer of 1945 nine submarines used the sonar to penetrate mine fields and enter the Sea of Japan. Following the war he spent a year at Boeing working on guidance elements for a "ground-to-air pilotless aircraft," leaving in 1946 to become an assistant professor of electrical engineering at Ohio State University's Wright Field Graduate Center.
In 1957 he joined Ramo-Wooldridge (later the Bunker-Ramo Corporation). Beginning in 1960 he led a program to automate the extraction of topographic data from aerial photographs, which culminated in 1964 with delivery of the first Universal Automatic Map Compilation System (UNAMACE), a computer-controlled photogrammetric instrument. He presented papers on the system in Portugal in 1964 and Switzerland in 1968, published in the International Archives of Photogrammetry and in Photogrammetric Engineering.
He later served as a professor of electricity and magnetism at Cal Poly San Luis Obispo, retiring in 1987. He died at his home in Scotts Valley, California, on July 30, 2012, at the age of 99.
Scientific contributions
During World War II Bertram designed the scanning switch that made the outputs of the twenty range filters of the PPI scanning sonar sequentially available to the display, work for which he received a Bureau of Ships Citation. At Ramo-Wooldridge and Bunker-Ramo he was a principal designer of the UNAMACE automated photogrammetry system, which measured ground elevations from conventional aerial photography to roughly one ten-thousandth of the flight altitude and made about fifty measurements per second.
After retiring, Bertram developed a classical, non-relativistic interpretation of electromagnetics. He argued for a rational or classical basis for electromagnetic phenomena and analyzed the Lorentz transform as an orthogonal conical transformation. Several of these papers appeared in Galilean Electrodynamics, a journal associated with critics of modern relativity theory, and he compiled the material as a work titled "Classical Derivation of Relativity." These proposals lie outside the scientific mainstream and have not been accepted by the broader physics community.
Honors
- Bureau of Ships Citation, for the invention of the scanning switch used in the PPI scanning sonar (World War II)
- Associate of the Institute of Radio Engineers (IRE), 1936
Abstracts
- 2008 - "The Lorentz Transform"
- 2002 - "Extended Lifetimes and Electromagnetics"
- 2001 - "A Classical Basis for Electromagnetics"
- 2000 - "The Lorentz Transform"
- 1997 - "A Rational Basis for Electromagnetics"
- 1997 - "Wave-Particle Interactions and the Lorentz Transform"
- 1996 - "The Differential Forces of Electromagnetism"
- 1992 - "Faraday's and Ampere's Laws"