Use of radiocarbon dating
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.What you need is a ruler, a reliable map to the reservoir: in other words, an organic set of objects that you can securely pin a date on, measure its C14 content and thus establish the baseline reservoir in a given year.
Libby and a few of his students at the University of Chicago: in 1960, he won a Nobel Prize in Chemistry for the invention.
The unstable nature of carbon 14 (with a precise half-life that makes it easy to measure) means it is ideal as an absolute dating method.
The other two isotopes in comparison are more common than carbon-14 in the atmosphere but increase with the burning of fossil fuels making them less reliable for study (2); carbon-14 also increases, but its relative rarity means its increase is negligible. After this point, other Absolute Dating methods may be used.
Radiocarbon dating is one of the best known archaeological dating techniques available to scientists, and the many people in the general public have at least heard of it.
But there are many misconceptions about how radiocarbon works and how reliable a technique it is.Other organic data sets examined have included varves (layers in sedimentary rock which were laid down annually and contain organic materials, deep ocean corals, speleothems (cave deposits), and volcanic tephras; but there are problems with each of these methods.