The researchers wanted to find out if they could identify a person's year of birth or year of death using precise measurements of carbon-14 levels in different post-mortem tissues.
They measured carbon-14 levels in various tissues from 36 humans whose birth and death dates were known.
Meet paleoclimatologist Scott Stine, who uses radiocarbon dating to study changes in climate. What we think of as normal carbon is called carbon-12: six protons plus six neutrons. Several times a year, scientist Scott Stine travels to the shores of Mono Lake, near Yosemite National Park. He's studying the long history of droughts in California, trying to determine how frequently they occur and how long they last.
Find out what it means for an isotope to be radioactive and how the half-life of carbon-14 allows scientists to date organic materials. But about one percent of carbon atoms have an extra neutron, giving them seven. Over the millennia, the water level has risen and fallen, as the area has cycled between wet periods and dry times. During times when the climate was dry, Mono Lake dropped down, exposed the shore lands, and allowed trees and shrubs to grow.
The researchers found that year-of-death determinations based on nails were accurate to within three years.