Carbon dating flaws seal
This would be the amount of time it would take for nine half-lives, and after that there would not be enough left to measure accurately.
There is no instrument on earth that can detect Carbon-14 in a specimen that is supposedly older than 18 half-lives. There are, however, many false assumptions that must be made in order to derive Carbon-14 dates and the knowledge of these false assumptions demonstrates the uselessness in this other-wise supposedly useful not varied over the years. There is ample evidence to prove that quite the opposite is true.
As the magnetic field decreases, more cosmic radiation penetrates the earths atmosphere and this causes a slow long-term increase in Carbon-14 production.
Then, in another 5,730 years, a second decay period would occur, leaving one quarter of a pound.
The process would continue, halving the amount left every 5,730 years until, theoretically, nothing remained of the original pound.
Prior to looking at the many flaws in the Carbon-14 Dating Technique, it should be noted that no radiometric technique is reliable.
They all start with similar flaws, but Carbon-14 has more than the rest.