The reliability of the other two assumptions these absolute dating methods rely on, that is, the starting conditions and no contamination of closed systems, are unprovable. Yet these can be circumvented somewhat via the isochron technique, because it is independent of the starting conditions and is sensitive to revealing any contamination. Data points that do not fit on the isochron are simply ignored because their values are regarded as due to contamination. That this is common practice is illustrated with numerous examples from the literature by Faure and Mensing (2005) and Dickin (2005). Yet much research effort remains to be done to make further inroads into not only uncovering the flaws intrinsic to these long-age dating methods, but towards a robust understanding of radioisotopes and their decay during the earth’s history within a biblical creationist framework. One crucial area the RATE project did not touch on was the issue of how reliable have been the determinations of the radioisotope decay rates, which are so crucial for calibrating these dating “clocks.” Accurate radioisotope age determinations depend on accurate determinations of the decay constants or half-lives of the respective parent isotopes.
Hence this method has given values for the Rb half-life from 47.0 ± 1.0 Byr (Flynn and Glendenin 1959) to 52.1 ± 1.5 Byr (Brinkman, Aten, and Veenboer 1965). The β-particles will be absorbed by molecules of the scintillator (emitting flashes of light) before they can be absorbed by other Rb atoms. The major problem with this method is that a low-energy cut-off at about 10 ke V must be applied to avoid the high background noise associated with liquid scintillation (Dickin 2005). Cambridge, United Kingdom: Cambridge University Press. At the same time the technology was developed to measure the concentrations of Rb and Sr by isotope dilution, combined with the separation of these elements by cation exchange chromatography. Faure and Powell (1972), Faure and Mensing (2005), and Dickin (2005) provide these and more details about the history of the development of the Rb-Sr dating method, and its theoretical basis and applicability. On the periodic table it is listed in the group IA column, which consists of Li, Na, K, Rb, Cs, and Fr. Rubidium is an element that does not form minerals in which it is a major constituent.
This has resulted in suggested values of the Rb decay rate has thus not been accurately determined, the Rb-Sr dating method is certainly not absolute and therefore cannot be used to discredit the young-earth creationist timescale.