In Memoriam - Gabriel Karl (1937 – 2020)

The department mourns the passing of Emeritus Professor Gabriel Karl FRSC from pneumonia on December 26 after a short stay in hospital.  We extend our condolences to his daughter and grandchildren.  Gabriel was born in Romania in the city of Cluj on 30 April 1937.  He was grateful to have survived the holocaust which claimed many of his family.  He grew up speaking both Hungarian and Romanian, eventually becoming conversant in six languages, and took his first degree at Babeş-Bolyai University in Cluj.  He came to Canada in 1960 and earned the Ph.D. in physical chemistry at the University of Toronto under the supervision of Nobel Laureate John Polanyi.  He spent an additional two years at Toronto as a post-doctoral fellow with Jan Van Kranendonk in the physics department.  While there he met and married his wife of over fifty years, Dorothy.  In 1966 he commenced a post-doctoral fellowship at Oxford Univer-sity with R.H. Dalitz in particle theory, the discipline in which he earned his reputation, and while there his only child, a daughter Alexandra, was born.  He returned to Canada in 1969 as an Assistant Professor at Guelph, became full Professor in 1975 and was awarded the designation University Professor Emeritus in 2002.

Gabriel was unusual in starting off with physical chemistry and moving into molecular physics before doing particle theory but in the 70’s he continued doing molecular physics with a colleague, J.D. (Duk) Poll, with whom he had worked while in Van Kranendonk’s group and who also joined the professorial ranks at Guelph about the same time as Gabriel.  In the mid-70’s he started a collaboration with Nathan Isgur that would be the high point of both of their careers.  They treated the quark model using spectroscopic ideas borrowed from atomic physics and their successes led to the model being more broadly accessible to the theoretical community.  These successes also led to his becoming the fourth professor at Guelph to be named a Fellow of the Royal Society of Canada in 1983.  He was particularly satisfied with his organization of a summer school in White Horse, Yukon in 1984.  In the mid-80’s he commenced a serious battle with cancer, ultimately successful, which might have ended most careers, but Gabriel persisted, publishing over 100 research papers garnering over 3000 citations and won the Canadian Association of Physicists Medal of Achievement in 1991.   This was followed by the Humboldt Prize for Canada-Germany Collaboration in 1992.  As a consequence of his extensive collaborations, Gabriel was visiting professor or scientist at CERN, Oxford, Rutherford Lab, Ludwig Maximilian University and the University of Arizona.  He was a frequent invited speaker and, for example, over a three year period in the late 90’s gave ten talks in five different countries.  He frequently visited the Aspen Center for Physics during the summer interacting with leading international theorists.  Many years later, as a consequence of such interactions, he was invited to speak at the 80th birthday celebration for Murray Gell-Mann in Singapore.  As recently as 2019 he hosted Sir C.H. Llewellyn-Smith as an honorary degree recipient at our university.  He was a regular member of the physics lunch table at the Faculty Club whose camaraderie reached a peak when John Simpson and Jim Hunt would join him in verbal sparring matches over the current political scene.  Gabriel was simply one of the most accomplished and admired physicists in our department’s history and will be sorely missed.