Outside the range of recorded history, calibration of the 14 clock is not possible.This means the above calculations are only evolution speculation and NOT backed up by real science.When granite rock hardens, it freezes radioactive elements in place.The most common radioactive element in granite is Uranium-238.
These are relatively low energies; the maximum distance traveled is estimated to be 22 cm in air and 0.27 mm in body tissue.
As soon as it dies, however, the C ration gets smaller.
In other words, we have a ‘clock’ which starts ticking at the moment something dies.
However, radioisotope dating may not work so well in the future.
Anything that dies after the 1940s, when Nuclear bombs, nuclear reactors and open-air nuclear tests started changing things, will be harder to date precisely.