Whole Earth History - Stephen Brush

Whole Earth History (Essay Review by Stephen G. Brush)*

CLAUDE C. ALBRITTON, JR. The abyss of time: Changing conceptions of the Earth's antiquity after the sixteenth century. San Francisco: Freeman, Cooper and Co., 1980. 251 p.; $12.50; pb $7.00

HENRY FAUL and CAROL FAUL. It began with a stone: A history of geology from the Stone Age to the age of plate tectonics. New York: John Wiley and Sons, 1983. xvii, 270 p.; pb $19.95

PAOLO ROSSI. The dark abyss of time: The history of the Earth and the history of nations from Hooke to Vico. Translated by Lydia G. Cochrane. Chicago: University of Chicago Press, 1984. (First published as I sengi del tempo: Storia della terra e storia delle nazioni da Hooke a Vico. Milano: Feltrinelli, 1979.) xvi, 338 p.; $35.00

ROBERT MUIR WOOD. The dark side of the Earth. London, Boston, and Sydney: George Allen and Unwin, 1985. (The British editions has the subtitle: The battle for the Earth sciences, 1800-1980.) x, 246 p.; $22.95

MOTT GREENE RECENTLY startled the readers of Osiris by declaring that the historiography of American geology is in such a primitive state that it is too early to start combing the archives for unpublished documents. The most urgent task, he argued, is to comprehend the growth of the science as a whole, using published works most of which have never been systematically studied by historians.¹ His remarks seem equally relevant to the Earth sciences in general, with a few isolated exceptions. In the absence of any reliable general survey of the history of the area of science that includes geology, geophysics, geodesy, meteorology, oceanography, hydrology, and ionospheric physics (to name only the major recognized disciplines), how can one intelligently approach a small part of this subject, and why should one concentrate on a single scientist or discovery when others that may be more important go unstudied?²

We do have a strong established tradition of research in one corner of the history of the Earth sciences: Early nineteenth-century British geology. An excellent recent example is The great Devonian controversy by Martin Rudwick, who admits that the time he spent on research for the book "covered a longer period than the scientific work that it describes and analyzes." He also admits that "there is no adequate general account of the earth sciences in the early nineteenth century" in spite of the numerous works on specific aspects of the subject. Nevertheless, he argues that his kind of detailed case history provides the kind of evidence needed to understand the dynamics of scientific communities.

Greene's monograph on Geology in the nineteenth century, though less comprehensive that its title suggests, is an excellent survey of ideas about tectonics and mountain formation, and serves to counteract the overemphasis of other historians on British geology by analyzing the works of several Continental and American Earth scientists.

A more recent focus for historical research is the establishment of plate tectonics in the 1960s. Here the wealth of published and unpublished documents can be supplemented by interviews since most of the major actors are still alive. Provoked by the claim by some of the scientists that Thomas Kuhn's model of scientific revolutions accurately describes this episode, historians and philosophers have vigorously debated the applicability of Kuhn's and other models to this case.

Fascinating as these studies may be, they can make only a limited contribution to our understanding of the history of Earth sciences until we can put them in a larger context. I am not objecting to their restrictions to such short time periods and to events in only one or two countries. As will be seen, a book that purports to cover the entire history of geology before 1960 in Europe, Britain, and America may also suffer a crippling limitation in scope. The problem is that most historians of science, like most Victorian and early twentieth-century geologists, do not see the Earth and its history as a whole; they do not tell us how the different disciplines within the Earth sciences interacted with each other and with the other sciences.

In planning this review I have selected four recent books that come close to giving the kind of general perspective that is most enlightening to me and, I assume, to readers who are not professional geologists or historians of geology. None of them appears to make any significant use of unpublished sources. Many other books of high scholarly quality are omitted or mentioned only in passing because they do not satisfy this particular criterion.

An important characteristic of geology is that it deals with the past. This is the dominant theme in the books by Rossi and Albritton and an important one in the other two. Later I will object that they do not go far enough into the Earth's past when describing the development of geology in the twentieth century. First, I must point to a radical difference between Rossi's approach and that of Albritton and the Fauls: So radical one would think they were writing about completely different subjects if names like Hooke, Burnet, and Buffon did not appear prominently in all three books.

Albritton and the Fauls find the origin of geology in the study of minerals, rocks, fossils, mountains, and other parts of the physical environment, and speculation about how they were formed; that is, the concerns of modern geology, foreshadowed in the writings of ancient and medieval philosophers. But Rossi sees the birth of geology as part of a change in worldview that took place in Europe during the seventeenth and eighteenth centuries, in which ideas about the Earth's antiquity were closely associated with debates about the existence of humans before the events recorded in the Bible, and with speculations about the origin of language. Geology, historiography, and linguistics were all part of a reorientation from the doctrine of a world created in its present form 6000 years ago and immediately populated by articulate men and women, to the conception of a physical-biological world evolving from chaotic and catastrophic beginnings to its present state through the operation of natural law. Similar philosophical and theoretical issues, and in many cases the same people, were involved in all three disciplines, and therefore, Rossi argues, one should not study their histories separately.

According to Rossi, the central question that eighteenth-century thinkers asked about the past was not whether the Earth's crustal rocks were precipitated from a universal ocean or forged by heat and pressure below the surface--the "Neptunist-Vulcanist" debate that occupies a prominent place in most histories of geology. Instead it was (Rossi, p. 199): "What relation could be established between the time-honored thesis of a world that issued perfect from the hands of God...and the image of the slow formation of the physical world during the course of time?...How could the image of a perfect Adam, a creature of divine wisdom, be put into relation with the concept of a primitive mankind, living in a state of barbarism and emerging slowly, groping its way toward speech, the making of tools, and civilization?...How could one combat the claims of many nations to an immense age, to millennia that reached far beyond the time allotted to God's chosen people? How could these processes--which concerned both natural history and human history?--be made to fit within the six thousand years allowed by biblical chronology?"

Though he endorses Kuhn's approach to the history of science, Rossi does not follow the current fashion that sees scientific facts as "socially constructed." His evidence could even be used to refute the thesis of social construction in this case: The vast expansion of the geological time scale in the eighteenth and nineteenth centuries was not simply a result of changes in European society but one of their causes insofar as it undermined the authority of the Bible.

Albritton and the Fauls do not pretend that religious beliefs about the creation of the world had no influence on the early development of geological theories, but they treat them as marginal to science, and have no interest at all in the debate about pre-adamite humans and the development of language that Rossi considers so important to the establishment of the modern conception of the past. Their books present clear sequential narrative accounts, leading the reader in easy steps from antiquity through many interesting episodes to the twentieth century. Rossi's book is much harder to read?--in presenting a panorama of seventeenth and eighteenth century debates he jumps back and forth in time, indulges in esoteric arguments with other scholars, fails to establish needed logical connections, and tends to confuse the reader who lacks the author's broad knowledge of the sources. Nevertheless, his book represents the direction in which historical studies on the Earth sciences will have to go if they are to reach the standard now expected of scholarship in the history of physical and biological science.

When we come to the nineteenth and twentieth centuries?--the period with which Wood is entirely concerned and which occupies nearly half of the books by Albritton and the Fauls?--we find that it is not only the historians but the scientists themselves whose vision is too narrow. Whereas the seventeenth and eighteenth century scientists had been willing (some would say, too willing) to contemplate the entire Earth and its changes since the time of its formation, geologists after about 1800 explicitly limited themselves to the Earth's surface and its development in more recent time. This was especially true of British geologists who followed Charles Lyell.

In The dark side of the Earth, Robert Muir has articulated most clearly the problem of "seeing the Earth as a whole." He points out that geologists are unique among scientist in that they cannot (or could not until the 1960s) see the object of their study, because they are crammed onto it. Charles Lyell recognized as one of the "prejudices which have retarded the progress of geology" that we can study only the Earth's land surface, not what is under the ocean or deep underground (Wood, p. 7). But geologists accepted, perhaps unnecessarily, a further restriction: Many of them spent their careers in the field collecting rock samples that could be chipped away with a hammer and making detailed maps of localities; the largest object they could conceptualize was the mountain range. Only a few "globalists" like Leonce Élie de Beaumont, William Green, Clarence Dutton and Osmond Fisher could see beyond the rocks?--discrete human-sized objects?--to the processes that shaped and rearranged the Earth's entire crust. In the twentieth century it was not the geologists but the seismologists who first discerned the large-scale structure of the Earth. Wood identifies the historical precursors of plate tectonics as these globalists and seismologists rather than Alfred Wegener and others who proposed theories of continental drift.

Wood's book does not claim to be a history of modern geology at all but rather an account of (as the British edition is subtitled) "The battle for the Earth sciences, 1800-1980"?--a battle between geologists and geophysicists. But many of the major characters in his story are men who ought to be featured in any history of modern geology: the globalists (mentioned above), the mathematicians (William Hopkins, Lord Kelvin, George Howard Darwin, Harold Jeffreys), the oceanographers (Maurice Ewing, E.C. Bullard), and the seismologists (Robert Mallet, R.D. Oldham). Included also are those whose speculations about the origin of the Moon influenced theories about the arrangement of continents and oceans (G.H. Darwin, F.B. Taylor).

By contrast the book by Henry and Carol Faul exemplifies Wood's claim that geologists tend to "think small;" it does not mention most of the scientists just named and dismisses the others in a paragraph or less. It would be unfair, however, to criticize the Fauls' book as a narrowly conceived whiggish account simply because it presents the geologists' view of the history of their own science. Aside from the obvious fact that any expression of such a view is itself a useful historical document, this book belongs to a new "post-Whig" (if not "post-Kuhn") genre of writings by scientists on the history of science. These scientists are aware that professional historians have introduced new perspectives and standards of accuracy to research and writing on the development of science. They do not necessarily accept these new perspectives and they may be skeptical about the capacity of historians to grasp essential technical details; but they consult with them and understand the importance of going back to original sources rather than merely recycling mythical heroic accounts passed on from one generation of scientists to the next. The Fauls have produced a well-written book and I find little to criticize in what they say about those aspects of the subject they choose to cover; my major complaint is that their omissions seriously distort the overall picture.

It began with a stone tells us very little about how scientists described the state of the Earth below its crust, though even that little is more than we learn from The dark side of the Earth. The Fauls ignore the nineteenth-century debate about whether the Earth's core is solid, liquid, or gaseous, and the effect of this debate on geotectonic theories. They do summarize the seismological work leading to Beno Gutenberg's discovery of the mantle-core boundary in 1912, but they ignore the geologically more significant Mohorovicic discontinuity and the inner core found by Inge Lehmann in 1936. (As Carol Faul points out in her Preface, few women appear in the history of the Earth sciences; it is surprising that she omits the one woman who did make a really significant discovery about the internal structure of the Earth.) Even more important for an understanding of the physical properties of the Earth as a whole, including its magnetic field, is the conclusion established by Harold Jeffreys in 1926 that the outer core is fluid. The inner core appears to be solid, as K.E. Bullen maintained. The chemical composition of the core has also been a subject of vigorous debate, and is relevant to hypotheses about the origin and early development of the Earth. I was dismayed to find that none of the developments listed in this paragraph is mentioned (except as noted) by the Fauls or by Wood.

Theories of the origin of the Earth proposed during the past 200 years are also shortchanged by all of these authors. For example, none of them discusses the important relation between the nebular hypothesis and geological theories based on a cooling, contracting Earth. Wood does mention the "planetissimal" (i.e., planetesimal) hypothesis of T.C. Chamberlin and its relation to global theories of Earth structure: A planet assembled from cold solid particles might be vastly different from one condensed from hot gas. But the Fauls and Albritton, following Lyell's prejudices, seem to assume that cosmogony dropped out of geology after the time of Buffon and other eighteenth-century propounders of "theories of the Earth." Those theories are well described by Paolo Rossi in The dark abyss of time, but he does not venture into the nineteenth century.

The origin of the Moon might seem to be less relevant to Earth science than the origin of the Earth itself. But the idea that the Moon was spun off from the Earth, leaving behind the Pacific Ocean basin, was sometimes used by geologists to explain the arrangement of continents and oceans. The inference that the American continents split apart from Europe and Africa as a direct reaction to the escape of the Moon provided a catastrophic alternative to the gradualist hypothesis of continental drift. The spin-off (fission) theory of the Moon's origin, the most popular one during the period 1880-1940 and still alive today, was originally proposed by G.H. Darwin; it was Osmond Fisher who suggested that the birthplace was subsequently to become the Pacific Ocean.

Both Wood and the Fauls mention this theory but in very different ways. For Wood it is an example of the global approach preferred by those physicists and astronomers who looked at the Earth from outside. The Fauls completely omit G.H. Darwin's role, mentioning only Fisher's and Gutenberg's ideas about the Pacific scar as part of the history of continental drift theory. They claim that Fisher's ideas were "largely ignored," meaning that they were ignored by geologists because continental drift theory was ignored?--overlooking the widespread acceptance by others of the notion that the Moon came out of the Pacific Ocean. Wood's treatment illustrates the advantage of breaking out of the geologists' perspective in presenting the history of Earths science.

There is one part of the history of geology in which the role of non-geologists cannot be ignored: The age of the Earth. All four books discuss the famous controversy started by Lord Kelvin's calculation of the time required for the Earth to cool down from a presumed initial molten state. Both Albritton and Rossi have selected the phrase "abyss of time" to suggest the historical importance of the vast expansion in the accepted length of geological periods after the mid-seventeenth century?--just as both Rossi and Wood seem to have chosen the adjective "dark" to suggest the reluctance of scientists to venture too far into the perilous depths of space and time.

The concept of geological time, as Albritton points out, ought to be recognized "as one of the more wonderful contributions from natural science to general thought" (p. 9). In the period between Isaac Newton and Charles Darwin, the expansion of the time scale from the few thousand years of the theologians to the few millions of years of Charles Lyell undermined the authority of Biblical cosmology and allowed the growth of evolutionary schemes for the Earth and life. But geologists themselves, during the century following the publication of Lyell's Principles, had very little interest in quantitative measures of time; they only wanted to know relative times and sequences of geological periods. Kelvin's complaint was not that geologists had adopted the wrong value for the age of the Earth, but that they had no definite value at all, and recklessly postulated as much time as might seem to be needed for any geological result to occur by processes operating at their present rate.

Kelvin's calculations of the age of the Earth were essentially an application of Joseph Fourier's theory of heat conduction. Fourier himself did the same calculation but did not explicitly state the result, apparently because a time scale of a hundred million years was so much longer than anything seriously considered by the geologists of his time that it seemed to be irrelevant. Nevertheless Fourier clearly stated that his own motivation for developing heat conduction theory was the contemporary (circa 1800) interest in the cooling of the Earth. In order to solve his equation for heat conduction, Fourier developed the method of representing functions by trigonometric series. This in turn led to the discovery that discontinuous functions or those with discontinuous derivatives, previously not thought to be legitimate functions at all, could be represented by trigonometric expansions, and this in turn led to a broader definition of function in connection with set theory. Thus American school children in the 1970s, at the height of the "new math" craze, were taught that a function is a set of ordered pairs of numbers, no two of which have the same first member. That is one legacy of research on geological time?--though the casual connections are rather tenuous.

A more direct consequence is the principle of irreversible dissipation of energy. The flow of heat from high to low temperatures was first treated as an independent principle of physics in Fourier's theory. Kelvin pointed out its relevance to the limitation of the time available for life when he proposed a general principle of energy dissipation in 1852: At a finite time in the past the Earth was too hot for life, and at a finite time in the future it will be too cold. William Hopkins noted a similar time-directionality in Earth history, in the same year. Rudolf Clausius incorporated the idea into a generalized Second Law of Thermodynamics with the help of his entropy concept; the inexorable increase of entropy would lead to the "heat death" in which not only the Earth but the entire universe must eventually cool to a temperature near absolute zero. Earth science thus combined with physics to provide the apparent technical justification for fin-de-siècle cosmic pessimism.

In the twentieth century, as a result of the development of radiometric dating, the geological time scale was suddenly expanded by two orders of magnitude?--from tens of millions to billions of years. Albritton and the Fauls trace the reluctant but inevitable acceptance of this time scale by geologists following the leadership of Arthur Holmes. But now we encounter a most remarkable phenomenon; modern geologists seem to have redefined the term "age of the Earth" so that it means the set of intervals associated with geological epochs back to the pre-Cambrian, but beginning with the oldest known rock rather than the formation of the Earth itself. The study of the latter event is considered part of astronomy rather than geology. Geology textbooks do state that the Earth is now thought to have been formed 4.5 or 4.6 billion years ago, but this is not considered to be relevant to geology. Moreover, the name of the scientist who first arrived at this figure?--Claire Patterson?--is hardly ever mentioned, even though the proponents of earlier "wrong" numbers (Bishop Ussher, Lord Kelvin, et al.) are sometimes discussed. One might expect a book on the history of modern geology--especially one that claims to discuss "changing concepts of the Earth's antiquity after the sixteenth century"--to include some mention of the establishment, in the mid-1950s, of the currently-accepted value of the age of the Earth. But Albritton says only that the Earth is older than the oldest dated pre-Cambrian rock, 3,760,000,000 years. The Fauls are even vaguer, and Wood succeeds in saying nothing at all about the subject in a chapter titled "The age of the Earth."

Of course the age of the Earth has little significance except in relation to other ages; it is only when we can compare it to the ages of the Moon, Sun, stars, rocks, life on Earth, and the human race that it becomes interesting. Kelvin's estimate of the age of the Earth was important in the history of science because it was shorter than the time periods ascribed to geological processes and to evolution, and thus undermined confidence in the foundations of geology and biology. Similarly, the estimates of Holmes and others based on radiometric dating were historically important--because they were much longer than those of geologists based on processes such as the accumulation of salt in the ocean. Albritton recognizes this conflict, although he does not adequately describe the impact on geology of the gradual discrediting of purely geological methods for estimating time periods.

Another reason why the radiometric ages were important is of more general interest: In the 1930s and 1940s the age of the universe as estimated from the Hubble constant appeared to be less than, or at most about the same age as, the age of the Earth. This anomaly was one reason for the crisis in cosmology that led to the proposal of the steady-state (continuous creation) theory by Hoyle, Bondi, and Gold. In this case it was the astronomers, not the Earth scientists, who revised their time scale and eliminated the conflict. Not a word about this episode is to be found in any of the books under review.

Although I have found that all four books fall short of providing a satisfactory account of the history of Earth science, each in its own way represents historiographical progress. Albritton achieves coherence and sustains the reader's interest by focusing on a single problem, providing a dramatic account of changes in attitudes toward the earth's past over many centuries; other works on the age of the Earth have had more depth but less scope. The Fauls transcend some of the usual limitations of scientist-written disciplinary history by working largely from original sources and employing a lively style. Wood breaks out of the disciplinary-history mold by raising provocative questions about the self-definition of geology and its relation to other sciences. Finally, Rossi, in the most radical departure from traditional writing on the history of science, in the English language at least, sets the origin of modern geology in a rich cultural context.

Stephen G. Brush
Department of History
Institute for Physical Science and Technology
University of Maryland
College Park, MD 20742

Note added October 2002: More detailed discussion of several of the topics mentioned here may be found in my book A History of Planetary Physics, 3 vols., Cambridge University Press (1996).

1. Mott T. Greene, "History of geology," Osiris, 1 (1985), 97-116. A. Hunter Dupree responded to this prescription with barely-suppressed indignation in his review, "A landmark in the cumulative literature of the history of American science," History of science in America, news and views, 3:4 (December, 1985), 1-3. Following Greene's response, which suggested that historians had given more attention to the external aspects of American geology than to its internal development, Dupree accused Greene of being a "hard-rock positivist." Ibid., 4:1 (1986), 1-2.

2. The closest approach to a general survey is D.H. Hall, History of the earth sciences during the scientific and industrial revolutions with special emphasis on the physical geosciences (Amsterdam, 1976), but it is much more restricted in scope than its title implies. For guides to the literature see Roy Sydney Porter, The history of the earth sciences: An annotated bibliography (New York, 1983); S.G. Brush and H.E. Landsberg, The history of geophysics and meteorology: An annotated bibliography (New York, 1985); William A.S. Sarjeant, Geologists and the history of geology: An international bibliography from the origins to 1978, (5 vols. New York, 1980).

3. Martin Rudwick, The great Devonian controversy: The shaping of scientific knowledge among gentlemanly specialists (Chicago, 1985), xxii.

4. Ibid., 3.

5. Mott T. Greene, Geology in the nineteenth century: Changing views of a changing world (Ithaca, 1982).

6. William Glen, The road to Jaramillo: Critical years of the revolution in Earth science (Stanford, 1982), and the papers of Henry Frankel: "Why drift theory was accepted with the confirmation of Harry Hess' concept of sea-floor spreading," in Cecil J. Schneer, ed., Two hundred years of geology in America (Hanover, 1979), 337-353; "The reception and acceptance of continental drift theory as a rational episode in the history of science," in S.H. Mauskopf, ed., The reception of unconventional science (Boulder, 1979), 51-89; "Hess' development of his seafloor spreading hypothesis," in Thomas Nickles, ed., Scientific discovery: Case studies (Dordrecht, 1980), 345-366; "The development, reception and acceptance of the Vine-Matthews-Morley hypothesis," HSPS, 13 (1982), 1-39; "The continental drift debate," in H.T. Engelhardt and A/L/ Caplan, eds., Scientific controversies (New York, 1986), 203-248.

7. J. Tuzo Wilson, "The current revolution in Earth science," Royal Society of Canada, Transactions, 6 (1968), 273-281; Wilson, "A reply to V.V. Beloussov," Geotimes, 13:10 (1968), 20-22; A. Cox, Plate tectonics and geomagnetic reversals (San Francisco, 1973), 5; Ursula B. Marvin, Continental drift: The evolution of a concept (Washington, 1973), 189-190; A. Hallam, A revolution in the Earth sciences: From continental drift to plate tectonics (Oxford, 1973), 106-108.

8. David B. Kitts, "Continental drift and scientific revolution," American Association of Petroleum Geologists, Bulletin, 58 (1974), 2490-2496, also in Kitts, The structure of geology (Dallas, 1977), 115-127; W. von Engelhardt, "Das Erdmodell der Plattentektonik: Ein Beispiel fur Theorienwandel in der neueren Geowissenschaft," in Alwin Diemer, ed., Die Struktur wissenschaftlicher Revolution und die Geschichte der Wissenschaften (Meisenheim am Glanm 1977), 91-109; Henry Frankel, David B. Kitts, Rachel Laudan, and Michael Ruse, "Philosophical consequences of the recent revolution in geology," PSA 1978, 2 (1981), 195-273; Rachel Laudan, "The method of multiple working hypotheses and the development of plate tectonic theory," in Nickles (ref. 6), 331-343; Laudan, "Redefinitions of a disciple: History of geology and geological history," in L. Graham et al., eds., Functions and uses of disciplinary histories (Hingham, 1983), 79-104; Richard Nunan, "Novel facts, Bayesian rationality, and the history of continental drift," Studies in history and philosophy of science, 15 (1984), 267-307.

9. Faul and Faul summarize the ideas of Suess and his followers in two pages (219-220); they also discuss Dutton, whose theory of isostasy they recognize as "the key to vertical movements on a large scale," but they drop the subject after this one tantalizing remark (p. 207). For Suess and other globalists see Greene (ref. 5).

10. S.G. Brush, "Nineteenth-century debates about the inside of the Earth: Solid, liquid or gas?" Annals of science, 36 (1979), 225-254.

11. S.G. Brush, "Discovery of the Earth's core," Eos, 47 (1982), 891-898; "Inside the Earth," Natural history, 93:2 (1984), 26-34.

12. Philip Lawrence, "Heaven and Earth-The relation of the nebular hypothesis to geology," in W. Yourgrau and A.D. Breck, eds., Cosmology, history, and theology (New York, 1977), 253-281.

13. Joe D. Burchfield, Lord Kelvin and the age of the Earth (New York, 1975).

14. Stephen G. Brush, The temperature of history (New York, 1978); D.R. Dean, "'Through science to despair:' Geology and the Victorians," in J. Paradis and T. Postlethwaite, eds., Victorian science and Victorian values (New York, 1981), 111-136 (New York Academy of Sciences, Annals, 360).

15. Burchfield (ref. 14); Francis C. Haber, The age of the world: Moses to Darwin (Baltimore, 1959); Dennis R. Dean, "The age of the Earth controversy: Beginnings to Hutton," Annals of science, 38 (1981), 435-456.