A major contention of young-earth creationists* is that radiometric dating* (measuring radioactive decay) is not reliable because the rate of nuclear decay was greater in the past than it is in the present.
First, this contention creates more problems than it solves. Simply put, the nuclear radiation rate necessary to make sense of a six-thousand-year-old universe would have been lethal to plant, animal, and human life.
Furthermore, physicists have not simply presumed decay rates to be consistent. They have made a concerted effort to disprove radiometric dating by subjecting radioactive atoms to extreme temperatures, extreme pressures, and a variety of electromagnetic variations. To date, however, no change in the rate of decay of any geologically significant radioactive isotope has been discovered.
Finally, the age of the earth as determined through radiometric dating processes corresponds to age parameters projected by such astronomical measurements as star life, which also demonstrates the age of the earth to be hundreds of times older than that presumed by young-earth creationists.
One thing is certain. Present projections regarding the age of the earth are wholly insufficient for the evolution of even the most basic of all protein molecules. Indeed, present age projections wholly undermine the evolutionary hypothesis.
he looked, and made the nations tremble.
The ancient mountains crumbled
and the age-old hills collapsed.
His ways are eternal.
For further study, see Davis A. Young and Ralph F. Stearly, The Bible, Rocks, and Time: Geological Evidence for the Age of the Earth (Downers Grove, IL: IVP Academic, 2008).