Radiometric Dating and Reason — Part 4
Old-Earth advocates insist that radiometric dating methods are accurate and reliable, but they've put the shoes on the wrong horse. Not only do radiometric dating methods require three basic assumptions that are improbable at best, some of those assumptions mask important secondary assumptions. In addition to unscientific assuming, they get wildly varying results (such as rocks known to be 60 years old testing to be 133 million years old, and ranges of a hundred million years or more). More than that, the age of the world has been calculated by using meteorites, not Earth rocks — which has several major assumptions as well.
The Rubidium-Strontium method has all of the aforementioned assumptions and problems, plus a few more. For one thing, adequate quantities of rubidium-containing minerals suitable for testing are not exactly common in nature. Another difficulty is determining the extremely long half life. Opponents of recent creation do not have anything substantial upon which to base their assumptions. Despite the bad science, secularists fight to keep their erroneous dating methods, because bacteria-to-biologist evolution requires long ages.
Here is an article on radioactive decay, and it has side bars for people who like to do the math.
Using rubidium (Rb) decay as a clock to date minerals was first suggested by Otto Hahn and Ernst Walling in 1938. Five years later, Hahn performed the first age determination using this method.If you're ready for the rest of the article, click on "Alkali Metal Dating, Rb-Sr Dating Model: Radioactive Dating, Part 4".
Like potassium (K), rubidium is an alkali metal and therefore chemically behaves much like potassium. Physically, it has an ionic radius of 1.48 Å, which is close to potassium’s (1.33 Å) and therefore should move within a crystal structure in a similar manner. This allows rubidium to readily substitute for potassium in all K-bearing minerals.
Determining the half-life of Rb presents scientists with a challenge for two reasons. First is the extremely long half-life of Rb, and second is because Rb beta decays with a relatively small energy of 275 keV. During beta decay, the decay energy is shared; thus, the emitted beta particle has a spectrum of energies rather than a single unique energy, making direct detection of the beta particle difficult. From 1964 through 2012, seven attempts were made to directly measure the half-life of Rb. The results of these measurements have varied from 4.77 ± 0.10 x 1010 yrs. in 1964 to 4.967 ± 0.032 x 1010 yrs. in 2003. A value of 4.88 x 1010 yrs. is used by Gunter Faure and Teresa Mensing3 and is the current value recommended by the Union of Geological Sciences. Whether this decrease is real or simply due to better measurement techniques remains uncertain. In any case, there is some uncertainty in one of the critical parameters used by isochron dating models of Rb decay.