Carbon dating accuracy debate
Research has been ongoing since the 1960s to determine what the proportion of in the atmosphere has been over the past fifty thousand years.The resulting data, in the form of a calibration curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the sample's calendar age.By contrast, methane created from petroleum showed no radiocarbon activity because of its age.The results were summarized in a paper in Science in 1947, in which the authors commented that their results implied it would be possible to date materials containing carbon of organic origin.In 1939, Martin Kamen and Samuel Ruben of the Radiation Laboratory at Berkeley began experiments to determine if any of the elements common in organic matter had isotopes with half-lives long enough to be of value in biomedical research.They synthesized Libby and several collaborators proceeded to experiment with methane collected from sewage works in Baltimore, and after isotopically enriching their samples they were able to demonstrate that they contained radioactive .The older a sample is, the less (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by this process date to around 50,000 years ago, although special preparation methods occasionally permit accurate analysis of older samples.
This was revised in the early 1960s to 5,730 years, which meant that many calculated dates in papers published prior to this were incorrect (the error in the half-life is about 3%).
thus introduced takes a long time to percolate through the entire volume of the ocean.
The deepest parts of the ocean mix very slowly with the surface waters, and the mixing is uneven.
The development of radiocarbon dating has had a profound impact on archaeology.
In addition to permitting more accurate dating within archaeological sites than previous methods, it allows comparison of dates of events across great distances.