Besides the stable potassium isotopes and potassium, it is possible to produce a number of other potassium isotopes, but, as shown by the half-lives of these isotopes off to the side, they decay away. If the half-lives are billions of years, it is impossible to determine them from measuring over just a few years or decades. If layers contain dead plant material, they can be used to calibrate the carbon ages. Soot from summer forest fires, chemistry of dust, occasional volcanic ash. Students Love Study.
There are two ways we know this didn't happen:
Isochron Dating and Age of Earth. The uncertainties on the half-lives given in the table are all very small. The ratio of the daughter isotope, neodymium, to another neodymium isotope, neodymium, is plotted against the ratio of the parent, samarium, to neodymium Similarly, there are good ways to tell quite precisely how much of the daughter product was already in the rock when it cooled and hardened. This is also true of a number of other igneous rock dating methods, as we will describe below. Books on scripture, theology, and science: