What is the half life of potassium argon dating
There is also evidence decay rates of the radioisotopes used for rock dating have not been constant in the past, as well as the possibility of a slight decline in the measured values of the total K decay half-life during the 78 years of determinations.
The uncertainties associated with direct half-life determinations are, in most cases, still at the 1% level, which is still significantly better than any radioisotope method for determining the ages of rock formations.
However, even uncertainties of only 1% in the half-lives lead to very significant discrepancies in the derived radioisotope ages. It continues to be mentioned, at one time or another, by every group active in geo- or cosmochronology (Schmitz 2012).
The recognition of an urgent need to improve the situation is not new (for example, Renne et al. From a creationist perspective, the 1997–2005 RATE (arth) project successfully made progress in documenting some of the pitfalls in the radioisotope dating methods, and especially in demonstrating that radioisotope decay rates may not have always been constant at today’s measured rates (Vardiman, Snelling, and Chaffin 2000, 2005).
But that determination in 2011 ignored the two liquid scintillation direct counting determinations in 20 which had agreed on a slightly lower total K decay half-life value of 1.248±0.003Byr.
So neither of these values has yet been adopted for standard use by the uniformitarian geochronology community. “The Decay of Potassium-40.” Philosophical Magazine 1 (2): 199–211.
Ironically it is the slow decay rates of isotopes such as Sm used for deep time dating that makes precise measurements of their decay rates so difficult.