Fortunately, Willard Libby, a scientist who would later win the 1960 Nobel Prize in Chemistry, developed the process known as radiocarbon dating in the late 1940s. In a nutshell, it works like this: After an organism dies, it stops absorbing carbon-14, so the radioactive isotope starts to decay and is not replenished.Archaeologists can then measure the amount of carbon-14 compared to the stable isotope carbon-12 and determine how old an item is.
What is more, we can measure the rate of spreading directly by GPS, SLR, and VLBI.
SYNONYMS OR RELATED TERMS: chronometric dating; absolute dates; absolute chronology; absolute age determination (antonym: relative dating)CATEGORY: chronology; technique DEFINITION: The determination of age with reference to a specific time scale, such as a fixed calendrical system or in years before present (B.
P., BP), based on measurable physical and chemical qualities or historical associations such as coins and written records.
Prior to the development of radiocarbon dating, it was difficult to tell when an archaeological artifact came from.
Unless something was obviously attributable to a specific year -- say a dated coin or known piece of artwork -- then whoever discovered it had to do quite a bit of guesstimating to get a proper age for the item.
Dedicated at the University of Chicago on October 10, 2016.