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Author Topic:   Validity of Radiometric Dating
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Message 3 of 207 (436287)
11-24-2007 10:47 PM
Reply to: Message 1 by Lili
11-24-2007 8:03 PM

Hi Lili, and welcome to EvC.
Since Dr. Howard is a current faculty member at my old alma mater, I feel a certain obligation to respond, heh.
I've looked at Dr. Howard's paper, and it does appear to me that he's trying to use a journal devoted to pedagogy to get around the peer review process in expressing his skepticism to radiometric dating. This is the impression I had of this paper.
Others, too, it seems. Karen Bartelt of Eureka College seems to have had the same impression; she wrote a response to this article in a subsequent issue. There are links at the bottom of the page to Howard's response, as well as that of the two reviewers. The reviewers comments are interesting: one doesn't care whether or not Howard is a secret creationist -- he appears to think that the exercise is a good one for teaching critical thinking. The other seems to have the same misunderstanding of radiometric dating that Howard does. At any rate, looking at Howard's scientific record, nothing leads me to believe that he has any real expertise in radiometric dating, and it shows.
However, it is possible that I may have been somewhat hasty in my characterization of Howard. In the HTML paper you cite, Howard states:
While some have questioned the accuracy of the dating methods based on the radioactive decay of 40K, the 40Ar-39Ar method has been demonstrated to be highly accurate in at least one case: a sanidine (KAlSi3O8) mineral, formed in the eruption of Mt. Vesuvius in 79 A. D., was dated by the40Ar-39Ar method in 1997, and the age was determined to be 1925 years old, differing by only seven years from the historically accepted age of 1918 years old. This amazing degree of accuracy may effectively counter arguments to the contrary.
So maybe Howard isn't so doubtful at all, and maybe it's unfair to disparage his attempt to foster critical thinking skills in his students.
Nonetheless, a sincere attempt at good pedagogy or not, he still doesn't seem to understand much about radiometric dating.
He also states that this applies to other methods of radiometric dating, so even independent verification by other radiometric dating methods does not validate the accuracy of any of them.
This is untrue. The fact is that all the other dating methods do give good collaboration of potassium-argon dating. The other radiometric methods involve very different parent chemical elements, different daughter elements, and different stages of intermediaries. All of these different method usual yield essentially the same ages for the same minerals and individual rocks, and different methods used in different parts of the world yield consistent dates when correlated with such things as index fossils.
For any individual dating method, it is possible that unidentified processes may yield inaccurate dates, but it is inconceivable that all the unidentified processes relevant to each different element in all the different minerals recovered in rocks with so many different histories would somehow conspire so that each method would give the same dates in each case. Frankly, if unidentified processes that make radiometric dating inaccurate were common, we would expect that no consistent dates would be obtainable at all. Each technique would yield a wildly different date for each individual sample, and each technique would date each stratigraphic unit, identified by the fossils it contains, very differently. In short, radiometric dating would be so unreliable that it would never have been adopted by geologists to begin with.
Furthermore, there is a technique called isochron dating which not only does not require knowing the initial amount of either the parent product or the daughter product. And, in addition, loss of or contamination by parent or daughter isotopes would corrupt the data to the point where the method would clearly indicate some sort of problem has occurred. Again, to get a seemingly valid by false date by this method would require an extraordinary conspiracy on the part of nature; the "leakage" would have to occur in just the right way in each and every crystal in the sample, regardless of the specific minerals, to yield a result that looks valid.

Progress in human affairs has come mainly through the bold readiness of human beings not to confine themselves to seeking piecemeal improvements in the way things are done, but to present fundamental challenges in the name of reason to the current way of doing things and to the avowed or hidden assumptions on which it rests. -- E. H. Carr

This message is a reply to:
 Message 1 by Lili, posted 11-24-2007 8:03 PM Lili has not replied

Replies to this message:
 Message 4 by RAZD, posted 06-27-2014 9:52 AM Chiroptera has not replied
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