André Reis has raised a series of questions about ice cores. He has done so in a very thoughtful and irenic manner. I will try to answer in similar fashion.
Firstly, I was limited to 1,200 words or less for each of the requested ice core essays. Clearly I was not going to be able to as present the methods used and the data derived from ice-core research as well as address the objections that have been raised. However, Reis has rescued me by raising these questions with such clarity that I have now been given another allotment of words by the Spectrum blogmeisters. I will attempt to summarize Reis’ objections before providing my present thinking on these challenging matters.
First Objection: I will begin with the thread that runs through the first two thirds of Reis’ questions.
On these lines, at first blush, Bull’s articles can be challenged because they are not in dialogue with the debate between the Christian scientific community and the evolutionary science on ice core dating that has been raging for the better part of the last three decades. The evidence presented is based on only one side of the equation, that of the uniformism, which has very clear expectations of what “must have” occurred in the ice cores based on what occurs today.
Response: Personally, I do not believe that the described mechanisms of evolutionary theory are sufficiently powerful to account for the biological diversity in the world around us (or in the world of the past). And, despite finding no evidence that a Noachian Flood ever covered the globe, I still—even more so—believe in a loving and gracious Creator God who continually interacts with his Creation. That said, I am unable to see how 135,000 years as evidenced by the GRIP ice core chronometer even speaks to the question of whether Darwinian evolution is correct or in error. To my way of thinking ice core research does not involve the principle of uniformity at all. It certainly does not involve Darwinian “survival of the fittest” (as ice cores are not alive and do not reproduce).
Let’s do a thought experiment utilizing Reis’, “what “must have” occurred in the ice cores based on what occurs today”. Suppose that, one day, a group of investigators become curious about how long snow has been falling on Greenland. They first measure the total thickness of the ice sheet that covers Greenland by drilling through it to bedrock. They don’t recover ice cores, they just measure the depth of the hole since that is all the information they need for what they are about to do. Then they determine the depth of 10 years of snow falling in the same area of Greenland now. Dividing this snowfall by 10 they determine the average annual snowfall. They then compress this thickness of snow into ice. If now they proceed to determine the time that snow has been falling on Greenland by dividing this one year’s accumulation of ice into the depth of the hole that they drilled initially—this would be determining what “must have” occurred in the ice cores based on what occurs today.
This they did not do. Rather the researchers recovered an ice core so that they could analyze samples of ice all the way down. Analysis of this sort produces evidence—empirical evidence—the basis upon which experimental science rests. These scientists found that samples of ice from 1,000 layers down, 2000 layers down, 3,000 layers down varied in CO2 levels, lead levels, sulphate levels etc. and that each layer on the way down showed the characteristic signature of a high ratio of oxygen 16/18 followed by low ratio of oxygen 16/18. They were certainly not assuming that whatever levels of lead, sulphate etc. they measured in the surface ice would be replicated in the deeper ice. They were not assuming uniformity.
If the ice cores really are what they appear to be then when scientists analyze ice 2,012 layers down they are analyzing ice that formed from snow falling on Greenland ~2012 years ago—ice that has remained frozen ever since. The levels of lead in those samples really do reflect the lead levels in the rain that fell in Galilee—and on Greenland in the time of Christ. Parenthetically, the lead assays were not done to provide a calibration point for ice core chronology 2,600 layers down—that is my application of the data. The scientists involved were simply quantifying how much lead was in the samples—that is empirical data, it is what scientists do! I simply pulled data for several samples from 3,000 to 6,000 B.C.E. to get an average background level for the start of my plot and then followed the rise in lead levels at shorter intervals thereafter to produce the graphs shown.
Second Objection: The binary layers are not annual but are “storm” layers as evidenced by the “hundreds “ of layers seen during the excavation of the P-38 fighter planes that crashed and were buried on the coast of Greenland during WW II.
Response: No ice cores have been drilled in this region. It is unsuitable. A primary requirement for drilling a core is that the ice be stationary and not be moving to one side or another—that would bend or break the drilling apparatus and make recovery of the cores impossible. In this coastal area of Greenland the ice layers are moving downslope toward the sea and hence sideways. No samples of the “layers” uncovered during the excavation of the snow (or ice—the accounts differ) that buried the planes were preserved and brought back for empirical analysis so it is difficult to know what the “layers” actually were. There is nothing to analyze. As Reis notes,“One of the witnesses counted hundreds of snow layers in the 250 ft. shaft from the surface to the planes below”. Whatever this particular witness saw—that is the extent of the available evidence.
It is highly unlikely that what he or she saw were the annual binary layers of ice core research. Annual binary ice layers are transparent when first formed and stay transparent for hundreds of years thereafter. They are not visible to the naked eye and could not have been seen by anyone looking down the excavated shaft. It requires the compression of a 20 cm layer of ice down to a layer 2-3 cm in thickness, by ~1,000 meters or so of overlying ice burden before the layers in a typical Greenland ice core become visible (see the middle photograph of three parts of an ice core in Part I).
Third Objection: There is a discrepancy in the number of layers between GRIP and GISP and they were drilled close together.
Response: I purposely included a comment in ice cores Part I addressing the uncertainty in precise enumeration of the years represented by a particular ice core and reported only the most conservative estimates. Although this question is of great interest to ice core scientists I am not sure it is relevant to the present discussion. The binary layers in the lower reaches (below 60-80,000 layers) of the Greenland ice cores get thinned to the point that they can no longer be clearly distinguished by optical scanning and all of the other methods for counting them (electrical conductivity, dust levels, sulphate levels, even the oxygen isotope ratios etc.) start to show wider and wider confidence limits. This means that various scientists will likely come up with different conclusions as to exactly how many annual layers are present. This is neither surprising nor particularly relevant to the reason that a report on ice cores was included in Bringing the Real World to Genesis. Once the layers are compressed and thinned so that they can be distinguished with the naked eye they remain countable in visible light down to at least 60,000. To me that seems a sufficiently large number to raise questions regarding the age of the earth as typically inferred from the first chapter of Genesis.
Fourth Objection: I began with a quote from André Reis and will close with another as his objection leads this discussion away from the scientific evidence towards the philosophical and theological conundrums that such evidence poses. He writes:
Thus, although deep-time ice core dating need not make one question Creationism per se, it does pose serious questions on the reliability of biblical historiography. The biblical chronologies, albeit not exhaustive or exact, do point in the direction of a not-so old age for the earth.
Response: I appreciate the force of André’s observation and have thought long and hard about the very critical question that he raises. I have come to, what is to me, a satisfactory solution regarding the reliability of biblical historiography. I will quote from myself and my sometimes co-author Fritz Guy.
For the several hundred years that the disconnect between Genesis and science has persisted there have been two main camps. Christians of a more conservative outlook have insisted that the controversy will in time be settled in favor of a literal understanding of the Genesis account. While science may for the time being be unsupportive, science changes its opinions, these Christians say, and science will eventually come around to both a short chronology for the Earth and for life upon it.
Many practicing Christians who are also practicing scientists disagree. For more than 300 years they have watched evidence accumulate that the earth is billions of years old, that the universe is even older (by something like seven or eight billion years), and that living things have long inhabited the Earth in ever-changing forms. Convinced by the weight of evidence from geology, paleontology, geochronology, genetics, etc., they have concluded that the Genesis story must be figurative and non-literal; that it must be poetry, metaphor, or myth.
…Given that this theology vs. science controversy pits two disciplines against each other, and given that (not surprisingly) each discipline considers its own evidence conclusive, it is understandable that the controversy shows little sign of abating any time soon.
This is the Foreword to a recent book, God, Sky, Land: Genesis 1 as the Ancient Hebrews Heard It, that Fritz Guy and I have written. It directly addresses the question that André Reis raises. In this book we adopt neither of the stereotypical positions described, positions which he appears to be assuming are the only options on offer. Neither do we explore an intermediate position such as a day-age approach, progressive creation, or theistic evolution. Instead, we proceed in a relatively unexplored direction. That direction is, in a manner of speaking, at right angles to the range of interpretations outlined above—we are of the opinion that what the original audience heard when Genesis was read (or more likely recited) to them was radically different from what we hear now. We believe that the solution to Reis’ question is to be found in exploring this difference—the difference between what they heard then and what we hear now
Thank you André for raising these very germane questions.
If the Spectrum blogmeisters will allow another paper in this series Fritz and I will be pleased to provide an “executive summary” of the arguments advanced in the book God, Sky and Land mentioned above. It is subtitled Genesis I as the Ancient Hebrews Heard It and is thus should be relevant to the series, Bringing the Real World to Genesis.
This is a companion discussion topic for the original entry at http://spectrummagazine.org/node/4839