Carbon-14 (14C ) is unstable, and degrades exponentially over time.All organisms have a certain amount of 14C present in their bodies – it is absorbed out of the atmosphere by plants during the process of photosynthesis, and transferred to animals when the plants are eaten.This creates an error in the "raw" age of about 2 percent.Since nearly all applications where the precise age is needed require calibration, this difference is removed in the calibration process].While alive, organisms experience a balance of 14C intake and dissipation.
Scientists have developed a first-of-its-kind method for determining the age of ancient artifacts without causing damage to the objects.Carbon-14 has a half-life of 5730 years (±40 years), meaning that (in accordance with the law of radioactive decay) it will take that length of time for half of the carbon present in an organism to decay into stable carbon isotopes.The levels of 14C present in a specimen can be measured in a variety of ways; however the invention of accelerator-based mass spectrometric techniques have drastically increased measurement accuracy, as it provides a count of the number of 14C atoms present in a sample.About one carbon nucleus in a trillion contains two extra neutrons, giving a mass of 14.This carbon-14 is radioactive and decays with a half-life of 5730 years.It has been used to date specimens up to 60,000 years in age.This analysis provides a radiocarbon age of the sample, which must then be calibrated in accordance with a radiocarbon dating calibration curve such as the one pictured below.A variety of factors have caused the amount of 14C present in the atmosphere to vary over time, resulting in deviations between the age predicted by radiocarbon dating and the absolute date of a specimen. Sample contamination must be carefully avoided to ensure measurement accuracy. Cornell University Press, Itha “Dating In Exposed and Surface Contexts”, ed.: Beck, Charlotte. Seminar Press, New York: NY, 1973 “Radiocarbon Dating”. C (carbon-14) in the upper atmosphere as a result of bombardment by neutrons in so-called cosmic rays: high-energy particles bombarding the Earth's atmosphere from outer space. On formation, the newly-born carbon atom quickly oxidizes to form a molecule of carbon dioxide (COC being produced annually is more or less constant, whereas the quantity being destroyed is proportional to the quantity that exists, it can be shown that the quantity in the atmosphere at any given time will be more or less constant: the processes of production and decay of C, which need not concern us in this article.If nobody else, Jull and Hodgins should be able to confirm the details of the tests run.Here is what I’ve been able to determine (or guess) from Krosney, however, who gives the most detailed account that is available to me right now. Christian Askeland has given us a blog post update at Evangelical Textual Criticism, including this exciting quote from that blog post: “The National Geographic Society granted the Arizona AMS laboratory permission to send me the actual results, and I am publishing an update on the dating of the Tchacos Codex based on the findings.” Also, “The lab had six test results.”] Krosney’s Account The raw data (such as it is) is reflected in the account presented by Krosney on pp.