George Richard Isaak, 1933-2005

Born in Poland in 1933, George Isaak received his Bachelor's degree from the 
University of Melbourne in 1955 and a Master's degree at the same institution in 1958. 
After two years as a research physicist at ICI, where he first developed the 
technique of resonant scattering spectroscopy, he moved to the University of 
Birmingham, England in 1961, first as a research associate and later as a lecturer, 
gaining his PhD in 1966 under the supervision of P. B. Moon. 
He was promoted to Senior Lecturer in 1969, to Reader in 1982, and became a 
Professor of Physics in 1984. 

His  pioneering work in resonant-scattering spectroscopy led to the first detection 
(published in 1979)of the solar five-minute oscillation as a global phenomenon in 
observations of the sun as an unresolved star. He led the High Resolution Optical 
Spectroscopy Group at the University of Birmingham, which was the first to operate a 
world-spanning network of observing sites for helioseismology; the group first obtained 
observations from Haleakala and Tenerife in the summer of 1981 and has operated a six-site,
partially automated global network since 1991. The BiSON network, as it was later dubbed, 
is still operating and has produced the longest continuous time series of helioseismic 
observations. 

Although he will be remembered for his contributions to low-degree solar seismology, 
George was also well aware of the importance of stellar seismology, and tireless in his 
efforts to apply the resonant-scattering techniques to solar-like stars such as Procyon, 
measuring not only their radial velocities but also their magnetic fields. 

He was awarded the Max Born Medal and Prize by the Institute of Physics and the 
German Physical Society in 1985, the Hughes Medal by the Royal Society (London) in 1993, 
and the Herschel Medal of the Royal Astronomical Society in 1996.

He was an author on over 150 papers on solar and stellar seismology; the fact that 
relatively few of them bear his name as first author is a testimony to his generosity 
and humility, as is the frequent appearance in the acknowledgements -- and sometimes 
in the author lists -- of the names of technical staff who helped with the work.

Even after his retirement in 1996, George remained actively involved with the BiSON group
and also took up an Adjunct Faculty position at the University of Minnesota, carrying out 
several observing runs at that University's observatory near Tucson, Arizona.

George was a memorable character. Though he spent most of his working life in Birmingham, 
he retained his Australian citizenship and his distinctive East-European accent. 
His insightful contributions from the floor at international helioseismology meetings, 
generally prefaced by 'I have a question and a comment' are still remembered and missed.

George had a contagious enthusiasm for his research that inspired generations of graduate 
and undergraduate students. His knowledge of, and curiosity about, physics and 
astrophysics were both deep and wide, leading him to see connections that eluded more 
pedestrian researchers; from early on, for example, he was fascinated by the possible 
cosmological implications of helioseismic measurements.

Rachel R. Howe, (National Solar Observatory, Tucson)