CASCA has lost its most distinguished member. On March 3, Dr. Gerhard Herzberg died at the age of 94.
GH, as all his scientific colleagues called him, began his scientific studies in Germany in 1924. He had wanted to be an astronomer, but was persuaded that technical physics was more appropriate for someone whose family had little means. He first studied at the Technical University in Darmstadt where he received a Doctorate in Engineering Physics in 1928, and then went to the University of Gottingen as a post- doctoral fellow. His education in Germany coincided with the early development of quantum mechanics there. After a second post-doctoral year at the University of Bristol, he returned to a position in Darmstadt, but in 1934 had to give it up because his wife was Jewish.
Fortunately for Canada he was assisted in finding a position at the University of Saskatchewan, and arrived there in September 1935. These were productive years for his research in atomic and molecular spectroscopy, and for writing. He translated his book on Atomic Spectra and Atomic Structure and wrote his equally renowned books on the Spectra of Diatomic Molecules and the Infrared and Raman Spectra of Polyatomic Molecules. His third book on molecular physics was published in 1966, the Electronic Spectra and Electronic Structure of Polyatomic Molecules.
In 1945, Otto Struve of the University of Chicago rekindled his early interest in astrophysics and enticed him to the Yerkes Observatory. Then in 1948, the National Research Council invited GH to Ottawa to establish a laboratory for fundamental research in spectroscopy. Many young scientists passed through that laboratory on their way to eminent careers, including Michael Feast, Boris Stoicheff, Harry Kroto, and Takeshi Oka.
The Nobel Committee awarded the Chemistry Prize to GH in 1971 for his many contributions to molecular spectroscopy, particularly the historically important recording and analysis of the spectrum of methylene, a difficult task that took him almost two decades. This free radical is an intermediate short-lived transient in some chemical reactions. It has also been found in the interstellar medium.
GH's investigations of molecular spectra led directly to several astronomical results. With A.E. Douglas in 1941, he measured the laboratory spectrum of CH+ and showed that it matched interstellar absorption lines observed by W.S. Adams at Mt.Wilson. He demonstrated the presence of H2 in the outer planets by measuring the pressure-induced spectrum of H2. Later his work on the quadrupole spectrum of H2 was very useful in analysing these transitions in the spectra of planets, and in shocked and radiatively excited interstellar gas. In 1974, GH worked with Hin Lew at NRC to measure the spectrum of H2O+ in the laboratory and identify it in the spectrum of Comet Kohoutek. In my own research involving the UV spectra obtained with the Copernicus satellite, I made considerable use of the laboratory data on H2 and HD published by Herzberg and his colleagues, including Izabel Dabrowski at the Ottawa laboratory.
It was Herzberg and Douglas who suggested the use of hydrogen fluoride (HF) in the absorption cell used by Bruce Campbell to monitor very small velocity variations in stars.
In 1975, the National Research Council combined several related sections and named the new entity the Herzberg Institute of Astrophysics. It consisted of combining the Space Physics and Spectroscopy Sections from the Division of Physics with the Planetary Sciences Section, the Radio Astronomy Section, the Algonquin Radio Observatory, the Dominion Astrophysical Observatory, and the Dominion Radio Astrophysical Observatory from the Division of Electrical Engineering. Both the DAO and DRAO had been transferred to NRC from the predecessor of National Resources Canada in 1970. At one time the Herzberg Institute included High Energy Physics, and at another time Optical Components Research, but following a budget cut in 1994 it has shrunk to only the astronomy groups.
GH was greatly loved and much admired by his colleagues as a "gentleman of science". He was a humanist who lent his name to many worthy causes, especially those that espoused human rights, freedom of belief, and academic freedom. He was a strong, consistent, and unwavering supporter of scientific research for its own sake, not only because it is a worthy cultural activity for society to support, but also because it has proved to be an excellent way of achieving unforeseen technological advances.