Radiocarbon dating is a key tool archaeologists use to determine the age of plants and objects made with organic material. But new research shows that commonly accepted radiocarbon dating standards can miss the mark -- calling into question historical timelines. Archaeologist Sturt Manning and colleagues have revealed variations in the radiocarbon cycle at certain periods of time, affecting frequently cited standards used in archaeological and historical research relevant to the southern Levant region, which includes Israel, southern Jordan and Egypt. These variations, or offsets, of up to 20 years in the calibration of precise radiocarbon dating could be related to climatic conditions. Pre-modern radiocarbon chronologies rely on standardized Northern and Southern Hemisphere calibration curves to obtain calendar dates from organic material.
The Story of Carbon Dating
BBC - History - Ancient History in depth: The Story of Carbon Dating
When news is announced on the discovery of an archaeological find, we often hear about how the age of the sample was determined using radiocarbon dating, otherwise simply known as carbon dating. Deemed the gold standard of archaeology, the method was developed in the late s and is based on the idea that radiocarbon carbon 14 is being constantly created in the atmosphere by cosmic rays which then combine with atmospheric oxygen to form CO2, which is then incorporated into plants during photosynthesis. When the plant or animal that consumed the foliage dies, it stops exchanging carbon with the environment and from there on in it is simply a case of measuring how much carbon 14 has been emitted, giving its age. But new research conducted by Cornell University could be about to throw the field of archaeology on its head with the claim that there could be a number of inaccuracies in commonly accepted carbon dating standards. If this is true, then many of our established historical timelines are thrown into question, potentially needing a re-write of the history books. In a paper published to the Proceedings of the National Academy of Sciences , the team led by archaeologist Stuart Manning identified variations in the carbon 14 cycle at certain periods of time throwing off timelines by as much as 20 years. The possible reason for this, the team believes, could be due to climatic conditions in our distant past.
Radiocarbon dating of the Shroud of Turin
Since , scientists have reckoned the ages of many old objects by measuring the amounts of radioactive carbon they contain. New research shows, however, that some estimates based on carbon may have erred by thousands of years. It is too soon to know whether the discovery will seriously upset the estimated dates of events like the arrival of human beings in the Western Hemisphere, scientists said. But it is already clear that the carbon method of dating will have to be recalibrated and corrected in some cases.
The Shroud of Turin , a linen cloth that tradition associates with the crucifixion and burial of Jesus , has undergone numerous scientific tests, the most notable of which is radiocarbon dating , in an attempt to determine the relic 's authenticity. In , scientists at three separate laboratories dated samples from the Shroud to a range of — AD, which coincides with the first certain appearance of the shroud in the s and is much later than the burial of Jesus in 30 or 33 AD. The idea of scientifically dating the shroud had first been proposed in the s, but permission had been refused because the procedure at the time would have required the destruction of too much fabric almost 0. The development in the s of new techniques for radio-carbon dating, which required much lower quantities of source material,  prompted the Catholic Church to found the Shroud of Turin Research Project S.