When creation scientists studied granite samples, they made interesting discoveries.The samples were from a mile below the earth, which, according to inflated evolutionary years, were 1.5 billion years old.The method assumes, among other things, that the earth's age exceeds the time it would take for C-14 production to be in equilibrium with C-14 decay.
In reality, its measured disequilibrium points to just such a world-altering event, not many years ago.
Outside the range of recorded history, calibration of the 14 clock is not possible.
The resulting C-14 is unstable and decays back to N-14 with a measured half-life of approximately 5,730 years.
Thus the ratio of stable C-12 to unstable C-14, which is known in today's open environment, changes over time in an isolated specimen. As long as the tree lives, it absorbs carbon from the atmosphere in the form of carbon dioxide, both C-12 and C-14.
But, carbon dating can't be used to date either rocks or fossils.