Posted on 11/12/2003 8:25:52 AM PST by bondserv
The Downfall of Uniformitarianism 11/04/2003
Can major paradigm shifts occur in science today? Check this one out.
You’ve seen it on TV science programs and in textbooks: plumes of hot magma from deep in the Earth’s mantle rise through the crust and erupt on the surface (the IMAX movie Yellowstone has computer graphics of the whole process). Perhaps you’ve seen animations of the Hawaiian Islands riding over a “hot spot” and building its chain of volcanoes over millions of years on its slow, drifting journey. Textbook diagrams show cross-sections of Earth’s crust, with lava erupting from channels rooted deep in the mantle, while crustal plates float and drift atop deep convection currents.
That’s all defunct now, and so is a lot of the uniformitarian dogma associated with it, claims Warren B. Hamilton (Colorado School of Mines), in an extensive article in this month’s GSA Today.1 Uniformitarianism is out, catastrophism is in. Now, don’t get the idea Hamilton denies the Earth is billions of years old; he still accepts the 4.567 billion year figure, the condensation of Earth from a solar nebula, and all that. But he replaces Charles Lyell’s old premise “the present is the key to the past” with a new picture that seems to pay homage to Stephen Jay Gould. He calls his model “Punctuated Gradualism.” How serious is the subject? Enough for him to entitle his paper, “An Alternative Earth,” and for it to get prominent press in a journal of the world’s leading geological society.
Here’s the overview Hamilton provides of his paradigm, and the timeline of catastrophic events he now envisions (Note: Ga = giga-annum, i.e., a billion years. Emphasis added in all quotes):
The Earth described here differs profoundly from that accepted as dogma in most textbooks and research papers. Crust and upper mantle have formed a mostly closed system throughout geologic time, and their dramatic temporal changes are responses to cooling. The changing processes define a Punctuated Gradualism and not Uniformitarianism. Major stages in Earth evolution:While much of this timeline looks standard, some of the underlying changes to assumptions are striking. The rhetoric is also notable in that the new view is revolutionary, and overthrows long-held beliefs about uniformitarianism and plate tectonics. Notice his confidence in the abstract: “Plumes from deep mantle, subduction into deep mantle, and bottom-up convective drive do not exist.” In his Overview, he outlines how the old ideas have died:
- 4.567–ca. 4.4 Ga. Hot accretion and major irreversible mantle fractionation. Giant bolides continue to ca. 3.9 Ga.
- 4.4–3.5 Ga. Era of nearly global felsic crust, too hot and mobile to stand as continents.
- 3.5–2.0 Ga. Granite-and-greenstone era. Permanent hydrosphere. Old crust cooled to density permitting mafic melts to reach surface. Diapiric batholiths mobilized from underlying old crust.
- 2.0 Ga–continuing. Plate tectonic era. Distinct continents and oceans. Top-down cooling of oceanic lithosphere enables subduction that drives plates, forces spreading, and mixes continental as well as oceanic crust into upper mantle.
The conventional model (e.g., Turcotte and Schubert, 2002) of Earth’s evolution and dynamics postulates that most of the mantle is little fractionated, major differentiation continues, and continental crust has grown progressively throughout geologic time; through-the-mantle convection operates, lithosphere plates are moved by bottom-driven currents, and plumes rise from basal mantle to surface; and plate tectonics operated in early Precambrian time. All of these conjectures likely are false. They descend from speculation by Urey (1951) and other pioneers, reasonable then but not now, that Earth accreted slowly and at low temperature from fertile chondritic and carbonaceous-chondritic materials, heated gradually by radioactive decay and core segregation, and is still fractionating.Hamilton explains that “The notion of a cold, volatile-rich, young planet has long since been disproved,” but its corollary of an unfractionated [i.e., homogeneous, and therefore fluid] lower mantle no longer can stand up to the facts; “major constraints” now rule this view out in favor of shallow crustal activity from the upper mantle and crust. This includes radioactive heating, of which he says, “Earth’s heat loss, now largely of radiogenic heat, is much overstated in the standard model.” He suggests a value 70% the earlier one, and states, “thermodynamic and mineral-physics data require that nearly all radioactivity be above 660 km (Hofmeister and Criss, 2003),” i.e., no deeper than 400 miles. At that depth there is a discontinuity that could not be breached by a magma plume.
Many published models are misleading: colors are saturated for lower-mantle anomalies one-tenth or one-fifth the amplitude of upper-mantle ones, huge unsampled volumes are assigned average values or populated with spherical-harmonic artifacts, illusory continuity is generated by severe smoothing and sharpening, cross sections are placed where subduction interpretations look most plausible. Models account for only a few tenths of traveltime variance, and have not been tested by attempting to squeeze solutions back into upper mantle. Nonsubduction alternatives receive little evaluation.
What’s most interesting about this story is not the new model, which may become the next discarded paradigm in the future, but the frank and revealing charges made against proponents of the old model: that they cheated, lied, and used irrational arguments to prop up their beliefs. Is that possible in science? You read it right here.
Creationists have similarly argued against the standard model for a long time and maybe now are getting some comeuppance. Dr. Walter Brown, for instance, has complained that deep mantle magma plumes are impossible, because the kinematics and thermodynamics would force the channels shut (see his paragraph on volcanoes and lava). Volcanism, therefore, must occur at shallow depths.
What can we learn from this paradigm shift? Make no mistake: confident-sounding scientific models, replete with professional jargon, (maybe even this one here - cf. 11/14/2002 headline), are written by fallible human beings. Like a hollow idol on a pedestal, a popular theory about the unobservable past might gleam in the sun for awhile, till toppled by tremors of fact. Broken on the ground, it is swept away and forgotten, and then a new hollow idol takes its place. Why hollow? Because no observer was there to corroborate the processes or the vast periods of time they are assumed to take. Remember Grand Canyon! It was the prototypical case of a phenomenon requiring millions of years, yet now the consensus is growing that it was formed catastrophically and recently (see 07/22/2002 headline). It should seem foolish to place one’s faith in the conjectures of mortals instead of in the testimony of an authoritative Eyewitness.
Those not beholden to secular geological conjectures might well consider what this paradigm shift may do to other geological conjectures. It may well cause a domino effect on current models in subjects as diverse as radiometric dating (which assumes pristine, unprocessed material from the deep mantle), planetary differentiation, seismology, volcanology, magnetic field dynamo theory, and even the origin of life. This model tinkers with temperatures, chemistry, the nature of the core and mantle, the timing of continents, and a host of geophysical processes affecting land and sea. Evolutionists had better revisit their assumptions about the early earth and what this does to their beliefs.
Now that mantle plumes and deep plate tectonics are out, who knows what will happen next? Perhaps Hamilton’s shallow plate tectonics theory will topple for other reasons. It seems to hinder large migrations of plates, such as the belief that India migrated from lower Africa, crashed into Asia and built the Himalayas. His choice of terms, “punctuated gradualism,” recalls Stephen Jay Gould’s punctuated equilibria, the “Alternative Earth” model in biology. It arose out of frustration with the lack of evidence for Darwinian gradualism, not because of positive evidence for the alternative. Gould replaced that “standard model” (neo-Darwinism) with – what? – a new model with even less empirical support, claiming, essentially, that evolution happens so fast it leaves no trace in the fossil record! Is Hamilton’s “Punctuated gradualism” a parallel in geology? It seems, at least, to nail the coffin shut on Lyell’s principle of uniformitarianism. Whatever happens next, we have just seen that major paradigm shifts are still possible in science. Kuhnians rejoice. Darwinians beware.
I have been there, you aren't kidding. The food, coffee and wine were top notch however.
understatement bump
It's just as accurate THIS way!!
You may suspect my interests are peculiar, but you have no proof.
I figured I was the last to get the word, really.
Titus 2:14
14 Who gave himself for us, that he might redeem us from all iniquity, and purify unto himself a peculiar people,
1 Peter 2:9
9 But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people;
(Maybe THIS will help.......)
The article highlights the "seemingly rather curious fact" that wherever Islam has imposed itself by conquest -- in what is now Egypt, Libya, Tunisia, Algeria, Morocco, Lebanon, Syria, Jordan, Turkey, and in the regions of historic Mesopotamia and Palestine -- "Christianity, which had been extraordinarily vigorous and rooted for centuries, practically disappeared." And, the article further notes, "for almost a thousand years, Europe was under constant threat from Islam, which twice put its survival in serious danger."
The explanation? As if taking a page from the historian Bat Ye'or, the article cites the Islamic precepts of jihad (holy war) and dhimmitude (inferior status of non-Muslims). It also stipulates that there are two meanings of jihad -- the spiritual war, or struggle, to be faithful to the teachings of the Koran, and the literal war that is waged to spread Islam. Both meanings, it says, are "equally essential and must not be dissociated, as if one could exist without the other." The article continues: "Obedience to the precept of 'holy war' explains why the history of Islam is one of unending warfare for the conquest of infidel lands." This same "obedience" has led to recent anti-Christian violence in Algeria, Pakistan, Nigeria, Java, East Timor, the Moluccas and, most dramatically, Sudan. Little wonder, as the article also reports, that between roughly one-quarter and one-third of the estimated Christian population of the Middle East has emigrated over the past decade to the free world.
Had enough with dinner, thanks!
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