mirrored file at http://SaturnianCosmology.Org/ For complete access to all the files of this collection see http://SaturnianCosmology.org/search.php ========================================================== The Age of the Earth T he generally accepted "mainstream" figure for the age of the earth is about 4.5 GY (4.5 * 109 years). The talk. origins FAQ on the subject suggests 4.5 billion years ± 1%, but for present purposes, we can be considerably more lenient with the margin of error since the "opposing" view puts the figure at about 6000 years, a difference of 6 orders of magnitude! Needless to say, the young-earth creationists dispute virtually all of the details involved in deriving a figure like the above, particularly all the "assumptions" (actually conclusions, but that's creationist language for you) having to do with radioactive decay and dating methods derived from radioactivity. It is, of course, true that radiometric methods are the only ones that yield absolute figures for the age of the earth. On the other hand, the precise age of the earth is not exactly what this matter is all about. I want to ensure that no creationists can take any comfort from the statement that only radiometric dating can provide an absolute age for the earth and interpret that to mean that there is no other evidence for an "old earth." Now, exactly what might be meant by "an old earth" is not yet completely clear, but most young-earth creationists are looking for ages on the order of 6,000 to 10,000 years and would certainly be more than a little distressed if they were forced to admit that the true age differed by as much as an order of magnitude from that figure. In practice, virtually no one is willing to consider ages of less than 6k, but even when pressed hard, even Bob Bales, probably the most persistent young-earth creationist to "grace" the talk.origins newsgroup over the years, tended to say nothing more committal than "probably less than 50k" (approximate quote, I don't have Bob's posts archived like some people do :-). Anyway, despite any limitations to radiometric methods for determining the full age of the earth, there are additional lines of evidence that can place lower limits on the earth's age. Several of these other, non-radiometric, methods require ages of considerably more than 6k years. Here are some of my favorites cribbed shamelessly from my own talk.origins archives. Visit the "official" archives too. 1) Dendrochronology This is dating from counting tree rings and correlating the patterns of wide and narrow rings between trees, thus working back farther than the age of a single individual tree. This methodology does not gain an order of magnitude, but patterns of tree rings have been traced back to ages that are at least significantly too old for the Ussher dates. For example, Becker et al., Nature 353:647-649, 1991 discusses a sequence of oak trees from Europe that yields a continuous chronology from the (1991) present back 9,928 years. The same authors also have a 1600 year old pine chronology which overlaps the end of the oak chronology. As interspecies comparison is difficult they had not yet fixed an absolute age for the pine chronology at the time of the 1991 article. It appears that they have since been able to correlate the pines with the oaks to obtain a chronology going back approximately 11,000 years. Ref: Becker, D. (1993) An 11,000 year German oak and pine dendrochronology for radiocarbon calibration. Radiocarbon 35:201-213. The oldest living trees are bristlecone pine trees from the White Mountains of California/Nevada. The oldest known live tree is 4763 years old (in 1964, the oldest was 4950 years old, but it was cut down in 1964 :-() and dead trees have been matched with live ones, extending the scale of bristlecone pine tree rings of known age back almost 9000 years before the present. Note, too, that even the ages of some of the living trees extend back beyond the usual dates of approximately 2400 BCE (4400 years ago) cited (and calculated from Biblical references) for the purported global flood. For more information on bristlecone pines, see The Ancient Bristlecone Pine and particularly the page on dendrochronology. Another study, finished in 1984 in Ireland, established an unbroken record of tree rings in oak trees from the "present" [i.e., 1984] to 7,272 years ago. Due to the fact that dendrochronology has been able to accurately calibrate 14C dating for such a period, there is also a broken chronology of trees found in Tasmania ranging in age from about 8000 BP to about 13000 BP (i.e., about 6000 BCE to about 11000 BCE). Ref: Barbetti, M. et al (1992) Radiocarbon variations from Tasmainian conifers; First results from late Pleistocene and Holocene logs. Radiocarbon 34(3):806-817. Obviously, this latter result will be slightly less convincing to young-earth creationists, since it is mediated by radiocarbon dating (at the near end), even though the 14C dating at that end had already been calibrated by strictly dendrochronological (ring-counting) methods. Note, though, that the sequence itself, at 5000 years, is already longer than the time from the alleged flood to the present, so this sequence would still be a problem for "flood geology" even if the absolute ages are ignored entirely. Creationists sometimes object that counting rings may not be reliable because some trees have been known to form multiple rings in a single year, but this can be and is controlled for. For example, trees can, under the proper environmental conditions, grow "false" (i.e., not annual) rings. This usually occurs when a lengthy "warm snap" in late winter "tricks" a tree into believing it is spring. This "warm snap" is then followed by the return of winter cold, and the tree reverts to winter dormancy (or a lengthy "cold snap" occurs in the middle of spring). This process is, however, extremely rare, and due to the relatively short duration of the "artificial" spring, under a microscope "false" rings are easily distinguished from real rings. In addition, the "warm snaps" that lead to "false" rings are almost invariably a result of micro-climatic conditions. One can correlate most of the "false" rings out by comparing the tree rings of trees separated by distance. For example, a dendrochronologist could compare redwood slabs from California and Oregon, and map out a reliable annual history. Furthermore, different trees require different environmental conditions to produce false rings. In all but the most unusual of cases, one can (if the material is available) cross-compare two different species of tree (e.g., a redwood and a maple) from the same area and eliminate most of the spurious "false" rings. In short, "false" tree rings are easily discernable (albeit not naively visible) in a single tree. Comparing trees from distinct geographic regions can be used to eliminate the vast majority of spurious rings, as can comparison of samples from distinct species of trees within a given region. The conclusion that trivially emerges from this data is that 6000 years is certainly insufficient to account for the tree-ring record. Even a less-constrained ("fast and loose") figure of 10,000 years, which is certainly stretching the "Bibilical record" line, cannot cover the ages found by counting tree rings, which are visible with the naked eye. Acknowledgements for much of the material above are due to Matt Brinkman, Peter Lamb, Chris Nedin, and, of course, Leonard Miller, of the U of Arizona, who compiled the Bristlecone pine site mentioned above. For more information on dendrochronology, see the Ultimate Tree-Ring Web Pages by Henri Grissino-Mayer. 2) Ice cores There is a talk.origins FAQ on this one. Matt Brinkman has compiled a beautiful summary of what is known. Briefly, though, people have counted annual layers of ice in places like Greenland and Antarctica. Naturally, the layers become harder to distinguish as you go deeper in the ice, but the principles are comparatively simple. It is comparatively easy to show (e.g., using inclusions of ash from known volcanic eruptions) that the layers do correspond to years rather than snowfalls as some people have asserted. As the ice gets compacted, the layers do become hard to distinguish and there are various theoretical methods used to test them, so someone who is inclined to disbelieve in them may feel uncomfortable accepting figures from beyond the point where people can actually see them reliably. However, even within this more restricted range, the news is bad for a "young earth." For example, in the Greenland ice divide (summit) core, it is possible to distinguish 40,000 annual layers before they grow too thin. Note that in those 40,000 years, there is no sign of a flood. Deeper in the core we get to ice laid down in the last interglacial (circa 120,000 years ago). According to both observations and theory (Milankovitch) this was a time in which the northern hemisphere was much warmer than today. Sure enough, at this point the annual layers reappear. Precipitation was much higher at this time (a consequence of the greater capacity of air to hold water vapor as temperature increases) and the annual layers are still 6mm thick despite the thinning induced by the flow of ice. Roughly another ten thousand layers can be counted. It is possible, though not yet confirmed, that more sophisticated isotopic analysis may allow annual layers to be counted between these two zones, perhaps back to around 70,000 years before present. This will be quite difficult because these layers have been considerably thinned by ice flow, and unlike the last interglacial layers, they were never that thick to begin with. Very preliminary results on this core were published in Nature volume 359, page 311. (Thanks also to Bill Hyde, from whom the last couple of paragraphs have been stolen. :-) See also Scientific American February 1998. 3) Varves Varves are annual layers of sediment laid down on lake bottoms. Depending on the climate and environment, you may get different numbers of layers per year, but in any case they cycle as 2, 3, or 4 distinct types of sediment and then repeat the same cycle again. In the Green River formation of what is now Wyoming, there are places with 20,000,000 thin varves, each varve consisting of a thin layer of fine light sediment and an even thinner layer of finer dark sediment. According to the conventional geologic interpretation, the layers are sediments laid down in a complex of ancient freshwater lakes. The coarser light sediments were laid down during the summer, when streams poured run-off water into the lake. The fine dark sediments were laid down in the winter when there was less run-off. (This process can be observed in modern freshwater lakes.) Thus, the varves of the Green River formation must have formed over a period of about twenty million years. Young-earth creationists insist that the earth is less than 10,000 years old and that the geologic strata were laid down by the Flood. In The Genesis Flood, Whitcomb and Morris therefore attempt to attribute the Green River varves to "a complex of shallow turbidity currents..." (p. 427). Turbidity currents--flows of mud-laden water--generally occur in the ocean, resulting from underwater landslides. If the Green River shales were laid down during the Flood, there must have been forty million turbidity currents, alternatively light and dark, over about three hundred days. A simple calculation (which Creationists have consistently avoided) shows that the layers must have formed at the rate of about three layers every two seconds. A sequence of forty million turbidity currents covering tens of thousands of square miles every two-thirds of a second seems ridiculously unlikely. A real age of 20 million years is far beyond even the most liberal of "literal" readings of Genesis. 4) Coral clocks Short explanation: the moon is slowly sapping the earth's rotational energy. Angular momentum is being transferred, by "tidal friction", from the earth's rotation to the moon's orbit. The earth should have rotated more quickly in the distant past, meaning that a day would have been less than 24 hours, and there would have been more days per year. There is an exceedingly strong correlation between the "supposed age" of a wide range of fossils (corals, stromatolites, and a few others -- collected from geologic formations throughout the column and from locations all over the world) and the number of days per year that their growth pattern shows. Modern corals deposit a single, very thin layer of lime once a day. It is possible with some difficulty, to count these diurnal (day-night) growth lines and to determine how old the coral is in days. More important seasonal fluctuations will cause the growth lines to change their spacing yearly so that annual increments can also be recognized much as in growth rings of trees. Professor John Wells of Cornell University began looking for diurnal lines of fossil corals. He found several Devonian (410-360 MYA) and Pennsylvanian (325-286 MYA) corals that do show both annual and daily growth patterns. He found that the Pennsylvanian forms had an average of 387 daily growth lines per annual cycle, and that the Devonian corals had about 400 growth lines. The agreement between these clocks, radiometric dating, and the theory of superposition is a little hard to explain away as the result of a number of unlucky coincidences in a 300-day-long flood. The coral clocks thus yield another, non-radiometric, confirmation of a lower bound for the age of the earth that is far beyond the figures given by the young-earth creationists like Morris, Gish and the ICR. Pointing as they do to a minimum age of approximately 400 million years and calibrated not by radioactivity but by "simple" Newtonian mechanics, denial of this figure requires denial of virtually all of physics. [The above excerpts, edited, reorganized, rewritten and reworked by me, are based on postings to talk.origins over several years by a number of people, some of whom I can't even identify from my files. :-( I have attempted to credit those that I can identify, but I suspect that Chris Stassen, Matt Brinkman, Bill Hyde, Karl Kluge and Bill Jefferys are among those whom I have not credited sufficiently.] W hat these various data show is that there is a good deal more than radiometric methods available to establish that the earth is much more than 6,000 years old. Anyone trying to build a history of the earth from the chronology given in Genesis will have a lot of trouble with any of these, let alone all of them. The correlations between these methods and the radiometric methods is much too high to be dismissed as coincidental. On to the next essay Back to the previous essay Back to my Religion page [Home] [Hot Buttons] [Tools] [Type] Send email to Paul Neubauer Page last modified 8-Aug-1998. _________________________________________________________________ NOTICE: The information presented on this page represents the personal views, ideas, and opinions of the author. This is not an official Ball State University web page. Links contained at this web site to other organizations, are presented as a service and neither constitute nor imply university endorsement or warranty.