Dating artifacts done
In a multi-year excavation project such as the one at Isthmia, hundreds of thousands of objects and other cultural material fill the storage sheds and museum.
Processing decisions begin with the research design and the goals tailored for each project.Theoretically, if one could detect the amount of carbon-14 in an object, one could establish that object’s age using the half-life, or rate of decay, of the isotope.In 1946, Libby proposed this groundbreaking idea in the journal Physical Review.When the last excavated trench is backfilled with dirt and when survey is completed for another season, one is left with only the records, drawings, photographs, and cultural material to make sense of what everything means.The processing and interpretation of those material remains, in conjunction with the records, is the essential final step in completing the picture of past human activities occurring in an area over time.Archaeologists use many different techniques to determine the age of a particular artifact, site, or part of a site.
Two broad categories of dating or chronometric techniques that archaeologists use are called relative and absolute dating.
Known as radiocarbon dating, this method provides objective age estimates for carbon-based objects that originated from living organisms.
The “radiocarbon revolution” made possible by Libby’s discovery greatly benefitted the fields of archaeology and geology by allowing practitioners to develop more precise historical chronologies across geography and cultures.
Willard Libby (1908–1980), a professor of chemistry at the University of Chicago, began the research that led him to radiocarbon dating in 1945.
He was inspired by physicist Serge Korff (1906–1989) of New York University, who in 1939 discovered that neutrons were produced during the bombardment of the atmosphere by cosmic rays.
Korff predicted that the reaction between these neutrons and nitrogen-14, which predominates in the atmosphere, would produce carbon-14, also called radiocarbon.