Obviously, this works only for things which were once living.It cannot be used to date volcanic rocks, for example.Exacerbating this effect, non-living items cannot be dated!
The rate of decay of N in 5,730 years (plus or minus 40 years).
This is the “half-life.” So, in two half-lives, or 11,460 years, only one-quarter of that in living organisms at present, then it has a theoretical age of 11,460 years.
Anything over about 50,000 years old, should theoretically have no detectable C.
That is, they take up less than would be expected and so they test older than they really are.
This supposedly allows one to date an object by the proportion of 14-C to 12-C. Tests of Hawaiian lava flows known to be less than 200 years old have been dated up to 3 billion years old! That is, the scientists themselves do not know the effective range for 14-C.
Also, All carbon dates have a "plus-minus" probable error range. An additional problem is that the true half-life of 14-C is unknown2!
This will make old things look older than they really are.
Also, the Genesis flood would have greatly upset the carbon balance.
Scientists are drawing "logical" conclusions from an assumption of 14-C's half-life! Surrounding soil, water, vegetation and/or animal matter can even contaminate samples!
When this contamination occurs, it mixes the date for the item with the date of the contaminant.
Because of this, 14-C and it's breakdown product 12-C, typically stay in balance.