Radiocarbon dating after 1950
It is presumed that the proportion of atmospheric C is the same today as it was in 1950 (10), (11) and that the half-life remains the same.
Therefore, any expression of “before present” will mean “before 1950”.
Radiocarbon dating may only be used on organic materials.
Typically (6): The above list is not exhaustive; most organic material is suitable so long as it is of sufficient age and has not mineralised - dinosaur bones are out as they no longer have any carbon left.
The sample passes through several accelerators in order to remove as many atoms as possible until the C pass into the detector.
These latter atoms are used as part of the calibration process to measure the relative number of isotopes (9).