A lot of people have bought in to the Evolutionary doctrine of radiometric dating. I continually wonder at the gullibility (or perhaps, lack of perceptibility and logical thinking) of so many people.
The usual responses upon hearing that I reject radiometric dating is the arrogant and insulting statement that I simply don't understand science or how can I question the science of Physics?
To begin with radiometric dating is not science, it is technology. One carefully collects rock samples. Labs run the samples through their machines and out come measurements or ratios of the quantities of certain isotopes. I don't know of any Creationist who objects to the good use of technology. The problem does not lie here, but in what happens next. The resulting data is interpreted according to certain assumptions to compute radiometric ages for the rock samples.
The following quotes are from McDougall I. and Harrison, T.M., 1988, "Geochronology and Thermochronology by the 40Ar/39Ar Method", Oxford Monographs on Geology and Geophysics No. 9., pp. 11, 12. This list of assumptions for the Ar/Ar method is indicative of all radiometric dating assumptions and schemes. This book is a non-Creationary, pro-radiometric dating book. [my comments in brackets]
"As with all isotopic dating methods, there are a number of assumptions that must be fulfilled for a K-Ar age to relate to events in the geological history of the region being studied. These same assumptions also apply to the 40Ar/39Ar method, although this latter technique provides greatly increased opportunities for their testing. The principal assumptions are given below with brief comment as to their validity, and will be further discussed implicitly or explicitly in the following chapters."
"1. The parent nuclide, 40K, decays at a rate independent of its physical state and is not affected by differences in pressure or temperature. This is a major assumption, common to all dating methods based on radioactive decay; the available evidence suggest that it is well founded (Friedlander et al., 1981). Although changes in the electron capture partial decay constant for 40K possibly may occur at high pressures, theoretical calculations by Bukowinski (1979) indicate that for pressures experienced within a body of the size of the Earth the effects are negligibly small." [Creationists have no problem with Physics.]
"2. The 40K/K ratio in nature is constant. As 40K is rarely determined directly when ages are measured, this is an important underlying assumption. Isotopic measurements of potassium in terrestrial and extraterrestrial samples indicate that this assumption is valid, at least to the extent that no differences greater than about 3% have been reported in the 39K/41K ratio. The evidence for the essentially constant isotopic ratios for the potassium isotopes will be presented in more detail subsequently." [This point is accepted a valid by most Creationists.]
"3. [This is one of the most important assumptions in radiometric dating! ] The radiogenic argon measured in a sample was produced by In situ decay of 40K in the interval since the rock crystallized or was recrystallized. [REALITY!] Violations of this assumption are not uncommon. [ i.e., they are common] [Rationalization to try to explain why radiometric dating is still valid even though this assumption is invalidated!] Well-known examples of incorporation of extraneous 40Ar include chilled glassy deep-sea basalts that have not completely outgassed preexisting 40Ar*, and the physical contamination of a magma by inclusion of older xenolitic material. Further examples will be discussed later, as the 40Ar/39Ar method allows the presence of extraneous argon to be recognized in some cases."
"4. Corrections can be made for nonradiogenic 40Ar present in the rock being dated. For terrestrial rocks the assumption generally is made that all such argon is atmospheric in composition with 40Ar/36Ar 3D 295.5, and although this commonly is so, there are exceptions. Various ways of assessing this assumption are available including the use of isotope correlation diagrams. Extraterrestrial samples such as meteorites and lunar rocks have nonradiogenic argon of quite different composition to that of atmospheric argon, but corrections often can be made satisfactorily, particularly as the nonradiogenic contributions usually are minor." [This assumption is needed to try to resuscitate radiometric dating after assumption 3 is invalidated thereby invalidating the entire methodology. This is damage control after the fact. ]
"5. [The second most important assumption of radiometric dating!] The sample must have remained a closed system since the event being dated. Thus, there should have been no loss or gain of potassium or 40Ar*, other than by radioactive decay of 40K. [REALITY!] Departures from this assumption are quite common, [Rationalization to try to explain why radiometric dating is still valid even though this assumption is invalidated!] particularly in areas of complex geological history, but such departures can provide useful information that is of value in elucidating thermal histories."
"These basic assumptions must be tested and assessed in each study that is undertaken. [Assumptions are assumed true. It is a logical fallacy to try to prove, test or assess them valid (AKA circular reasoning). They may be proven false, but never true.] This is usually best done by measuring a suite of rocks or minerals from the area under study. The consistency or lack of consistency of the results, together with knowledge of the geology of the area, allows assessment of some of these assumptions, and provides the basis for conclusions as to the reliability and meaning of the measured ages. As will become evident later, an important advantage of the 40Ar/39Ar dating method is that the assumptions underlying calculation and interpretation of an age are more readily assessed than is the case for conventional K-Ar age measurements." [Because"As with all isotopic dating methods" (see first line of quote above), then all radiometric dating involves circular reasoning!]
Since, assumptions 3 and 5 are commonly false, then the whole concept is pseudoscience nonsense (to put it kindly). If you want to accept radiometric dating, go ahead. No amount of rationalization can make falsified assumptions valid. I prefer my logic to be sound.
Allen Roy
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