Age calculation carbon dating
Both methods rely on the ongoing production of radiocarbon in the upper atmosphere.
Nitrogen atoms high in the atmosphere can be converted to radiocarbon if they are struck by neutrons produced by cosmic ray bombardment.
In contrast, from 1955 to 1963, atmospheric radiocarbon levels almost doubled.
Since then they have been dropping back toward natural levels.
Before the nuclear age, the amount of radiocarbon in the environment varied little in the span of a century.
Now, new applications for the technique are emerging in forensics, thanks to research funded by NIJ and other organizations.
In recent years, forensic scientists have started to apply carbon-14 dating to cases in which law enforcement agencies hope to find out the age of a skeleton or other unidentified human remains.
For example, one person is twenty years old is the same as one person is in the twenty-first year of his/her life.
In one of the traditional Chinese age systems, people are born at age 1 and the age grows up at the Traditional Chinese New Year instead of birthday.