Arthur Holmes' unifying theory: from radioactivity to continental drift
Cherry L. E. Lewis, 2002. "Arthur Holmes' unifying theory: from radioactivity to continental drift", The Earth Inside and Out: Some Major Contributions to Geology in the Twentieth Century, David R. Oldroyd
Download citation file:
Only ten years after the discovery of radium in 1897, Arthur Holmes (1890-1965) began his studies at the Royal College of Science in London where he completed the very first U/Pb age determination designed specifically for that purpose. His continued interest in radioactivity and its effect on the thermal history of the Earth led to his early recognition that the age of the Earth should be measured in thousands, not hundreds, of millions of years, a subject he pursued for the rest of his career, despite considerable opposition from traditional geologists. Following a short period in Burma, he returned in 1922 to find that not only had attitudes to the age of the Earth changed, but that geologists were embroiled in a new controversy over continental drift. Evidence is put forward that suggests Holmes may have been aware of Wegener's theories virtually from the time they were proposed, and that by 1924 he was already searching for his own theory which would explain all geological processes. His profound understanding of the effects of radioactivity on the internal processes of the Earth, and his advanced knowledge of petrology, placed him in a unique position to develop a mechanism for driving continental plates around the globe. The progression of his ideas for this mechanism - convection currents in the mantle - and the unifying theory that that led to, is traced through his papers and letters to colleagues.