English Science Archaeology A religious book about the Creation/evolution debate

Although it is certainly true that the amounts of argon and potassium can be accurately measured, it is exceedingly difficult to measure the logarithmic rate of decay of potassium 40. One of the main reasons is that potassium 40 decays into two elements, calcium 40 and argon 40. The proportion that decays into argon 40 compared to calcium 40 is called the branching ratio, and is only known by calibrating the dates that various values of branching ratios cause potassium-argon dating to ***yield***, against the uranium-thorium scheme.