抄録
The relative error in the determined radiogenic age is less than the relative error in the measured amount of a decay product, which always occurs in age determination experiments. This can be confirmed by calculating the error for the case when there is an error in the measured amount of the decay product while there is no (or negligible) error in the measured amount of the decay precursor at the present time. This is a paradox because the relative error in the radiogenic age would always be larger than that in the measured amount of the decay product, when we assume that there was no (or negligible) error in the initial amount of the decay precursor.