Carey, Samuel Warren
CAREY, SAMUEL WARREN
(b. near Campbelltown, New South Wales, Australia, 1 November 1911;
d. Hobart, Tasmania, 20 March 2002), continental drift, global tectonics, Earth expansion.
“Prof Carey,” as he preferred to be known (never “Sam,” except to his closest friends and colleagues), was an iconoclastic geologist who accepted and taught that the continents move relative to each other decades before this view became orthodoxy. Taking his cue from Alfred Wegener’s theory of continental displacement and Arthur Holmes’s version of mantle convection, he accepted the relative motion of the continents and developed and taught a theory of Earth that had some similarities with the plate tectonics view of Earth that emerged triumphant in the late 1960s. But in the late 1950s, at a time when paleomagnetic and other data were reviving interest in continental drift, he concluded that the production of new ocean floor as the continental blocks moved apart meant that Earth itself must be expanding. Through the next four decades, and well after the general acceptance of plate tectonics, he continued to elaborate and defend Earth expansion as his preferred alternative. Earth expansion attracted considerable interest in the 1960s and, even after the plate tectonics revolution, continued to have some adherents.
Early Life . Carey was born to Tasman George and Hannah Elspeth Carey at home on 1 November 1911, without doctor or midwife, in rural New South Wales in Australia after his mother had been thrown over a fence from a runaway carriage. He grew up in straitened circumstances. At the insistence of his mother, he walked to school in Campbelltown, some 3 miles distant, whatever the weather or illness, carrying his shoes in both directions in order to save wear on them. He completed his secondary school studies at Canterbury Boys High School with a focus on science; his subjects included advanced mathematics, physics, chemistry, and, at the suggestion of his physics teacher, geology. His academic achievements at Canterbury resulted in a scholarship for teacher training at the University of Sydney. This enabled him, the eldest of seven children, to enroll in 1929 as the Great Depression began. As a first-year student he intended to major in physics and mathematics, but in addition to those subjects and biology, he took geology as his fourth subject.
The teaching staff in geology, particularly Leo A. Cotton and William R. Browne, followed the lead of the influential example of the recently retired Professor Tannatt W. Edgeworth David in emphasizing both extensive fieldwork and a close knowledge of alternative theories and interpretations. Cotton, for example, wrote on polar wander and described in one of his courses Wegener’s theory of continental displacement (drift) as answering many problems in the Southern Hemisphere. Carey soon concentrated on geology, in part because of his enjoyment of the physical and intellectual demands of fieldwork and his love of such activities as rock climbing, camping, and cave exploration. For his bachelor of science and master of science degrees, he undertook research on Carboniferous and Permian rocks in New South Wales, which resulted in several publications. His experience at Sydney helped shape his personal credo, exemplified later in his teaching, research, and publications: “Disbelieve if you can!” In other words, do not accept the authority of the textbook, the teacher, or the majority view; instead, challenge what is accepted, attempt to find the best explanation, and then be prepared to defend it. In his later career, this led him first to accept, elaborate, and defend a version of drift and then to reject that in favor of a theory of Earth expansion.
Fieldwork in New Guinea . Although Carey intended to apply for a scholarship to Cambridge University in England to pursue his PhD, he instead took up an offer by Oil Search Ltd. to undertake field mapping and exploration in New Guinea, north of Australia. He worked there from 1934 to 1942. His experiences as the leader of field parties of thirty New Guineans, often isolated for weeks, reinforced his independence and self-reliance. His detailed observations in New Guinea, a geologically active region of both rapid erosion and uplift including those on the effects of the great Torricelli earthquake in 1935, underlined for him the vertical mobility of Earth’s crust. He drew on these experiences in completing his doctor of science thesis in 1939 on the tectonic evolution of New Guinea and Melanesia. His examiners included Arthur Holmes and H. A. Brouwer. Carey later claimed that he had to self-censor himself regarding some of the content because it might be too radical, not only his use of the idea of moving continents, but also his now accepted “orocline concept”; that is, that many mountain belts that were initially linear in form had subsequently been bent by relative movements of the crust. He was recalled to Australia in 1942 for debriefing and then permitted to enlist for military service. He volunteered for duty in Z-Force, a special unit formed to conduct raids behind enemy lines. After first serving in New Guinea, he returned to Australia where his most memorable exploit was to demonstrate by a highly successful mock attack on allied shipping in Townsville Harbor the potential of unconventional weapons and tactics. This resulted in official approval for a successful raid on Japanese shipping in Singapore Harbor.
Working in Tasmania . In 1944 Carey became the chief government geologist for Tasmania. In that capacity he reorganized the structure of the Survey of Tasmania, wrote many reports, and directed the preparation of many geological and mineral maps. Even after departing the survey to become a professor at the University of Tasmania, as a consultant he took a keen interest in the preparation of accurate regional maps, often employing aerial photography, for the survey and for the Tasmanian Hydro-Electric Commission. Many of these maps were completed by students and staff at the university.
In 1946 he was appointed foundation professor of geology at the University of Tasmania, in which capacity he hired staff and designed a challenging curriculum that carefully integrated lectures, laboratories, and fieldwork. He regarded the introductory course as critical and taught it, beginning in 1947, for many years. He used as the text Holmes’s Principles of Physical Geology(1944), which included a chapter on continental drift and an illustration of a possible mechanism based on convection currents in Earth’s mantle. In his lectures he presented the case for continental mobility, but his teaching was based on his credo that students should make their own observations, formulate their own explanations, and then be prepared to defend them against fellow students as well as himself. For the next few years, he was occupied with the design and construction of a building for the new discipline.
A Mobilist View . Carey began publicly defending and extending a mobilist view of Earth in 1955. The view that
he put forward resembled closely the plate tectonics version of “drift,” which triumphed in the late 1960s; that is, he taught and advocated the lateral motion of continents as a result of convection currents in Earth’s mantle with generation of new crust and disappearance of older crust. In 1954 he submitted a paper on his orocline concept to the Journal of the Australian Geological Society, and it was duly sent to three referees, each a professor of geology, a Fellow of the newly formed Australian Academy of Science, and an avowed opponent of drift. Their comments were both hostile and disparaging. He vowed never to become an academician or to submit another paper to the Journal. The paper, “The Orocline Concept in Geotectonics,” was published in 1955 in the friendlier Proceedings of the Royal Society of Tasmania and was soon widely cited by mobilists. In it he argued that mountain belts may undergo subsequent deformation through large, lateral crustal movement. One of his examples, based on geological and tectonic data, was the formation of the Bay of Biscay, along the French and Spanish coast, resulting from a clockwise rotation of Spain toward the Mediterranean and the consequent curving of once-straight mountain chains. This example was later widely cited during the revival of drift in the 1960s. He also published a refutation of Harold Jeffreys’s claim that the “fit” of South America to Africa used by proponents of drift as evidence for a previous connection of the two continents was relatively poor. Carey based his rebuttal on a physical fitting of scale
models of the two continents on a specially prepared globe and also through stereographic projection, though he noted that the fit was not absolutely perfect. There were a few small gaps, or “gores.”
Carey in 1955 began convening symposia on controversial topics both to stimulate debate and to expose his students to current debates. The first in the series was on marine sedimentation. The next was the most notable.
In 1956 Carey hosted the Symposium on the Present Status of the Continental Drift Hypothesis at the University of Tasmania. The timing was fortuitous: much new data about the topography of seafloors and the patterns of earthquake distribution were becoming available, and new paleomagnetic techniques were beginning to suggest that large-scale movements of Earth’s crust had indeed taken place. This was reflected in the collection of symposium papers, published in 1958 under the title Continental Drift, a Symposium. Both anti- and pro-mobilists participated, but the volume reveals a softening in the stance taken by several of the former, who made explicit reference to paleomagnetic studies as an important new source of evidence. In the late 1950s and early 1960s, as debates about rival theories of Earth continued, reference was often made directly or indirectly to the symposium as a key event.
An Expanding Earth . Carey’s own contribution to the symposium, composing nearly half the volume, rejected his own earlier mobilist interpretations and advocated a rapidly expanding Earth as the preferable global theory. It drew together many of his previous ideas and much of the new data. The mid-ocean ridges and associated earthquakes marked the locations where the continents had been joined together but had broken apart and where new seafloor then in-filled as the globe expanded. Likewise, the oroclines, as in the case of the rotation of Spain and the creation of the Bay of Biscay, resulted in the creation of new ocean floor, rift valleys, the Red Sea, and the Atlantic Ocean. All of this was compatible with Carey’s previously held view that new seafloor was being constantly created and spread through mantle convection as explained by Holmes, but he no longer accepted that this could be counterbalanced by the disappearance of older crust into the substratum. Therefore, there must have been a net expansion of the surface of Earth. Further, the “gores” or small gaps left when the continental blocks are reassembled into a single landmass disappeared if reassembled on an Earth of somewhat smaller diameter. Carey’s expanding Earth model attracted considerable attention, for it provided an elegant account for a wide range of old and new data. Moreover, the renowned physicist Paul Dirac had earlier speculated that the universal gravitational constant could diminish over time, an idea that had some currency in the late 1950s and 1960s, as in the work of Robert H. Dicke and Carl H. Brans.
Carey continued to refine his argument for an expanding Earth and to incorporate new evidence for it. The Expanding Earth, published in 1976, shortly before his retirement as professor, presented in a much more accessible manner the major points of his thesis along with supporting evidence. He incorporated a considerable body of relevant empirical data that had been published since the 1958 symposium and sought to answer some of the objections to expansionism, while granting the force of others. He acknowledged that a major objection to fast expansion was the absence of a known cause. To this objection he replied, “My first answer is that I do not know. Empirically I am satisfied that the earth is expanding” (Carey, 1976, p. 46).
Retirement for Carey did not mean the end of his research and writing. He continued to advocate Earth expansion as an alternative to the widely accepted theory of plate tectonics. He convened, contributed to, and edited the papers of a conference on Earth expansion (Carey, 1981). In his Theories of the Earth and Universe (1988) he gave an overview of the development of geological theories, which culminated in the theory of an expanding Earth. His last major publication, Earth, Universe, and Cosmos (1996), contains not only a defense of an expanding Earth, but also his final thoughts on Earth science and cosmology. Besides defending and seeking to refine his expanding Earth model, Carey continued to write reflective essays on his career, his experiences, and his view on various scientific topics for his family, friends, and others. He died peacefully in Hobart at the age of ninety.
The most complete bibliography of Carey’s works is in Patrick G. Quilty and Maxwell R. Banks, “Samuel Warren Carey 1911–2002,” Historical Records of Australian Science 14 (2003): 313–335. This also contains further biographical information including honorary degrees, awards and prizes, and memberships of learned societies. It is also available online from http://www.publish.csiro.au/nid/109/issue/745.htm. Official papers relating to Carey’s work at the University of Tasmania are located in the university archives. Other likely repositories of papers and correspondence include the Tasmanian Hydro-Electric Commission (now Hydro Tasmania) and Oil Search Limited (with respect to his work in New Guinea in the 1930s and 1940s).
WORKS BY CAREY
“The Orocline Concept in Geotectonics.” Proceedings of the Royal Society of Tasmania 89 (1955): 255–288.
“Wegener’s South American–African Assembly, Fit or Misfit.” Geological Magazine 92 (1955): 196–200.
“The Tectonic Approach to Continental Drift.” In Continental Drift, a Symposium, edited by S. Warren Carey. Hobart, Australia: University of Tasmania, 1958.
“The Expanding Earth: An Essay Review.” Earth Science Reviews 11 (1975): 105–143.
The Expanding Earth. Amsterdam and New York: Elsevier Scientific Publishing, 1976.
Editor. The Expanding Earth: A Symposium. Hobart, Australia: University of Tasmania Press, 1981. Includes four contributions by Carey: “Evolution of Beliefs on the Nature and Origin of the Earth,” pp. 3–7; “Tethys and her Forebears,” pp. 169–187; “Earth Expansion and the Null Universe,” pp. 365–372; and “The Necessity for Earth Expansion,” pp. 375–393.
Theories of the Earth and Universe: A History of Dogma in the Earth Sciences. Stanford, CA: Stanford University Press, 1988.
Earth, Universe, Cosmos. Hobart, Australia: University of Tasmania Press, 1996.
Elliston, John. “Professor S. W. Carey’s Struggle with Conservatism.” In Why Expanding Earth, edited by Giancarlo Scalera and Karl-Heinz Jacob. Rome: Istituto Nazionale di Geofisica e Vulcanologia, 2003.
Scalera, Giancarlo. “Samuel Warren Carey: Commemorative Memoir.” In Why Expanding Earth, edited by Giancarlo Scalera and Karl-Heinz Jacob. Rome: Istituto Nazionale di Geofisica e Vulcanologia, 2003.
H. E. Le Grand