Since that time, CALIB, now renamed Int Cal, has been refined several times--as of this writing (January 2017), the program is now called Int Cal13.
Int Cal combines and reinforces data from tree-rings, ice-cores, tephra, corals, and speleothems to come up with a significantly improved calibration set for c14 dates between 12,000 and 50,000 years ago.
Reimer and colleagues point out that Int Cal13 is just the latest in calibration sets, and further refinements are to be expected.
Filipino hot porsy - Testing the radiocarbon dating method
It was the first absolute scientific method ever invented: that is to say, the technique was the first to allow a researcher to determine how long ago an organic object died, whether it is in context or not.
Shy of a date stamp on an object, it is still the best and most accurate of dating techniques devised.
Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geologic time scale.
Among the best-known techniques are radiocarbon dating, potassium–argon dating and uranium–lead dating.
Beginning in the 1990s, a coalition of researchers led by Paula J.
Reimer of the CHRONO Centre for Climate, the Environment and Chronology, at Queen's University Belfast, began building an extensive dataset and calibration tool that they first called CALIB.
By allowing the establishment of geological timescales, it provides a significant source of information about the ages of fossils and the deduced rates of evolutionary change.
Radiometric dating is also used to date archaeological materials, including ancient artifacts.
Reliable estimates are possible, but with large /- factors.