John Gatenby Bolton, 5 June 1922 - 6 July 1993

Abstract

Since World War II astronomy has lived through its golden age undergoing a complete transformation. Before the war, astronomy meant optical astronomy and observations were confined to the use of the narrow range of visible spectrum capable of penetrating the earth’s atmosphere - about 1 octave in all. Since that time new advances have made it possible to observe at radio, infrared, ultra-violet, X-ray and gamma-ray wavelengths covering a spectrum of some 56 octaves. An exciting consequence of the new era has been the discovery of new classes of galaxies with extraordinarily high energy and luminosity, pushing back the limits of the observable universe beyond all expectations. What started this great revolution? It may be fairly said that it all began in 1948 in Sydney, Australia, when a three-man team led by a 26-year old Yorkshireman named John Bolton discovered that three distant objects, known from optical observations, were, extremely powerful emitters of radio waves. One, which Bolton called ‘Taurus A’, was located in our own galaxy; the Crab Nebula. The other two (‘Virgo A’ and ‘Centaurus A’) were external galaxies. This discovery marked the beginning of the new era in which the universe could be explored by means of its high- energy galaxies. The pursuit of this subject became the main theme of Bolton’s scientific life.