Gerhard Herzberg, Nobel Laureate in Chemistry, had broad interests and achieved supreme accomplishments in physics, chemistry and astrophysics. The high points in his research were many. In physics they were the work on atomic hydrogen and helium, and evaluations of energy levels and constants of molecular hydrogen and its isotopes. His determinations of many molecular structures and discoveries of spectra of the free radicals CH
2
and CH
3
, and of the Rydberg molecule H3, were each outstanding contributions in chemistry. In astrophysics, his reproduction in the laboratory of the spectrum of CH
+
, proving its presence in the interstellar medium, and of spectra of C
3
and H
2
O
+
and their presence in comets, his observation of the quadrupole spectrum of H
2
and his discovery of hydrogen in the atmospheres of the planets opened up new applications of spectroscopy for our knowledge of the universe. His classic volumes on molecular spectra and molecular structures remain as encyclopaedias of molecular knowledge for all time. And his famous laboratory, the ‘Temple of spectroscopy’, served as a home for hundreds of scientists around the world, and helped to bring Canadian science to international prominence.
Two-color photoassociation spectra of ultra-cold Cs (60D5/2)2 Rydberg molecule