Notice that something must have been alive to absorb C-12 and C-14.
Therefore it is not possible to date inorganic material.
Current understanding of the history of life is probably close to the truth because it is based on repeated and careful testing and consideration of data.
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.
The ratio of C-12 to C-14 is approximately 1 billion to one in today’s atmosphere.
All living things, directly or indirectly, absorb carbon from the atmosphere.
Levels of carbon-14 become difficult to measure and compare after about 50,000 years (between 8 and 9 half lives; where 1% of the original carbon-14 would remain undecayed).
The question should be whether or not carbon-14 can be used to date any artifacts at all? There are a few categories of artifacts that can be dated using carbon-14; however, they cannot be more 50,000 years old.
Carbon-14 cannot be used to date biological artifacts of organisms that did not get their carbon dioxide from the air.
This rules out carbon dating for most aquatic organisms, because they often obtain at least some of their carbon from dissolved carbonate rock.
by Dr Carl Wieland An attempt to explain this very important method of dating and the way in which, when fully understood, it supports a ‘short’ timescale.