Four assumptions that underlie radiometric dating methods
With uranium-lead dating, for example, the process assumes the original proportion of uranium in the sample.One assumption that can be made is that all the lead in the sample was once uranium, but if there was lead there to start with, this assumption is not valid, and any date based on that assumption will be incorrect (too old).Scientists, using rigorous methods have established a process to eliminate this problem by calibrating radiocarbon dating results to items of a known age.In this way, items of unknown age can be tested and an age determined to a reasonable degree of accuracy. More tomorrow where we explore the concept of isochron dating and how it neatly destroys most of the rest of these ‘issues’.(Aside, my dad doesn’t know how old I am, he usually misses by about two years, giving him an error of almost 5%.) Not only, is this not a ‘false assumption’. Oh and here’s a link to the Table of Contents for this set of creationist misconceptions.
It is more accurate for shorter time periods (e.g., hundreds of years) during which control variables are less likely to change.There are a number of implausible assumptions involved in radiometric dating with respect to long time periods.One key assumption is that the initial quantity of the parent element can be determined.A very common claim of young earth creationists in trying to reject the evidence for an old earth is to loudly proclaim that radiometric dating methods “makes assumptions” and that these “assumptions” are somehow fatally flawed or not supported by evidence.These claims generally land in three different categories: (1) radiometric dating assumes that initial conditions (concentrations of mother and daughter nuclei) are known, (2) radiometric dating assumes that rocks are closed systems and (3) radiometric dating assumes that decay rates are constant.