In 1979, Desmond Clark said of the method “we would still be foundering in a sea of imprecisions sometime bred of inspired guesswork but more often of imaginative speculation” (3).
AMS counts the quantity of C isotope is constantly formed in the upper atmosphere thanks to the effects of cosmic rays on nitrogen-14 atoms.
Because it reacts identically to C-12 and C-13, C-14 becomes attached to complex organic molecules through photosynthesis in plants and becomes part of their molecular makeup.
Animals eating those plants in turn absorb Carbon-14 as well as the stable isotopes.
It's development revolutionized archaeology by providing a means of dating deposits independent of artifacts and local stratigraphic sequences.
Libby in 1949, and has become an indispensable part of the archaeologist's tool kit since.