Joseph Henry Condon, a physicist, engineer and computer scientist, died on January 2 at the age of 76. He is perhaps best known as the co-creator of Belle, the world champion chess computer. Joe was born in Princeton, NJ on February 15, 1935, to the noted theoretical physicist, Edward Uhler (E. U.) Condon and Emilie Honzik Condon, and was named after the 19th century American physicist, Joseph Henry. Joe earned a bachelor’s degree in physics from Johns Hopkins University (1958) and a Ph.D. in physics from Northwestern University (1963). Immediately after finishing graduate school Joe joined the Metallurgy Research Division of AT&T Bell Laboratories at Murray Hill, NJ.
Joe’s initial field of research at Bell Labs was the study of the electronic band structure of metals by means of the oscillatory diamagnetic susceptibility (the de Haas van Alphen effect). His seminal studies in beryllium and silver, published between 1966 and 1968, showed that magnetic domains (later called Condon domains) form in non ferromagnetic metals when the oscillating differential magnetic susceptibility is greater than unity. He developed a theory of such domains and verified it experimentally. The study of Condon domains has continued through 2010.
By the late 1960’s Joe’s wide ranging interests led him to join the digital revolution that was in progress at Bell Labs. His initial contributions were in the emerging technologies of digital switching. In 1975 Joe joined the Computer Research Center at Bell Labs where the C programming language and the UNIX operating system were created. Joe and his colleagues used these tools to automate the laborious and error-prone task of manually converting a circuit drawing into a circuit board. They designed a system, the Unix Circuit Design System (UCDS), which automated the fabrication of prototype circuit boards from drawings. This system launched an era of rapid prototype construction for research and product development
Joe and Ken Thompson promoted the use of the C programming language for AT&T’s switching system control programs. Joe acquired a small AT&T PBX (telephone switch) that handled about 50 phones, he made the necessary hardware changes and Ken Thompson wrote the necessary software programs. The PBX code re-write in C was a success and hastened the adoption of C for all switching system’s software within AT&T.
Ken Thompson and Joe created the chess-playing machine named Belle. Joe designed custom hardware while Ken designed the software. The hardware evaluated board position, did piece move generation, and used a cache memory for previously evaluated board positions. Belle’s hardware could evaluate millions of board positions and generate all legal chess moves every second. The control software selected the best current move. Belle was compact and easily portable and was entered in many chess tournaments where it achieved a master rating. Belle won the world computer chess championship in 1980 and the U.S. computer chess championships in 1978, 1980, 1981, 1982, and 1986.
In 1982 Joe combined his twin passions for digital systems and physics in collaboration with Andrew Ogielski. At the time a hot topic in theoretical physics was the calculation of properties of a class of recently discovered complex magnetic materials such as spin glasses and various random antiferromagnets. Monte Carlo calculations were the approach of choice and required extensive computing capacity, well beyond the state of the art general computers of that time. Together they designed and built the “spin glass machine”, a dedicated computer especially designed for Monte Caro calculations that was 5-10 times faster than the Cray-1. The spin glass simulation work became a classic, and all physical predictions computed in this early work remain accurate to this day, despite immense increases in computing power over the thirty years since the “spin glass machine” was put to work.
Joe was a physicist, engineer and computer scientist noted for his insight and intuition into physical systems and for talented digital system design. His designs were parsimonious and supremely effective. He was a natural teacher and drew on his deep understanding of physics when explaining a problem in either basic physics or digital design. His curiosity was unlimited and his range of knowledge was extensive. Everyone who worked with Joe benefited from his ability to teach, his experience, and his mentoring, yet his collaborations were generous and never compromised by ego.
After his retirement in 1989, he continued to consult with Bell Labs for another 10 years. Joe had a delightful sense of humor and unlimited curiosity He loved American Indian crafts, classical music, the theater and to travel with his wife Carol in their RV. He was very active in The Religious Society of Friends (Quakers) and was a frequent volunteer in the FISH Hospitality Program.