And finally, they count all of the tree-rings, using the matching patterns to connect all the pieces, and they determine the age of the oldest piece of wood.
This is called a "long chronology." By dating the oldest piece of wood using the Carbon dating method and comparing the two dates, scientists can make the necessary adjustments to their calculations. Aardsma, "Myths Regarding Radiocarbon Dating," Impact, No.
Payen, et al.); Middle Holocene Age of the Sunnyvale Human Skeleton, Science (1983, with L. Payen, et al.); and Non-Concordance of Radiocarbon and Amino Acid Racemization Deduced Age Estimates of Human Bone: Implications for the Dating of the Earliest Homo sapiens in the New World, Radiocarbon (1983).
In relative dating, the temporal order of a sequence of events is determined, allowing the investigator to surmise whether a particular object or event is older or younger than, or occurred before or after, another object or event.
But in a dead organism, no new carbon is coming in, and its carbon 14 gradually begins to decay.
So by measuring carbon 14 levels in an organism that died long ago, researchers can figure out when it died.
Kra, editors); The Age of the Calaveras Skull: Dating the "Piltdown Man" of the New World, American Antiquity (1992, with L.
Slota, Jr.); Radiocarbon Dating: An Archaeological Perspective (1987); Major Revisions in the Pleistocene Age Assignments for North American Human Skeletons by 14C Accelerator Mass Spectrometry: None Older Than 11,000 14C Years B.