This does not mean that recalibration is bad, indeed it is necessary, but it should make one more soberly assess any reported dates as being tentative. We beat this "drum" because of the straightforward historical claims of Scripture.
There are two reasons uncalibrated dates must be mentioned: 1) this prevents people from making up any number they please, and 2) it is for the sake of posterity, where future scientists can check the results and apply new ideas of calibration. Radiocarbon dates are affected by many outside factors. That still puts the earth at over 20,000 years old.
The accuracy of the machines is not in question (especially modern ones, which are astoundingly accurate when properly zeroed in). But, any source of old carbon in the ancient environment can affect the amount of C-14 in a sample. So, why continue beating the 6,000 year old earth drum?
Examples: For all of these, and more, reasons, calibration is needed in C-14 dating. How certain are you that carbon dating is reliably able to give us dates back to 50KYA?
Thus, reports generally specify the ‘raw’ numbers and the ‘fudged’ numbers. With all that was said about the assumptions behind the measurements, about non-linear forcing functions (like an expected pulse of non-radioactive carbon at the time of the Flood), and add the two prior comments about the demonstrably changing magnetic field strength of the earth, and I submit there is a lot more "art" than "fact" when generating such dates.
See: The walls of Jericho, The story of Jericho, and Q and A pages on the Ice Age and radiometric dating. If that chronology is wrong, as many think, the calibration is wrong.
See also this useful offsite resource: Jericho chronology dispute. Robert Carter With more information than ever before, Christians can stand tall because the Word of God is real, authoritative and accurate. California: Stanford University Press, ISBN 0-8047-1569-6. Dendrochronology is used to determine variations in the C14/C12 ratio, but dendrochronology has assumptions that are not always valid (see bristlecone pine dating).Your support is vital in keeping this site going and growing. Here are a few references on 14C calibration for Anthony: Bard, E., Hamelin, B., Fairbanks, R. (1995), Radiogenic Isotope Geology, Cambridge University Press. They even miss the flood when it is staring them in the face.I read the scientific article on the carbon dating done on the Jericho site written by Bruins and Van Der Plicht. P: Late glacial fluctuations and cosmogenic isotope production, Science, v. Many people have struggled with the faith because of the age-of-the-earth issue, and many other have rejected the faith based on a perceived lack of answers to these questions.When I did the math from their results section of the YBP, they all turned out to be right around the year 1400 . (1970), Dendrochronology of bristlecone pines, Pinus aristata. Olsson (Ed.), Radiocarbon Variations and Absolute Chronology, Proc. Therefore, it behooves us to attempt to answer the challenge of naturalistic science whenever and where ever we can. Carbon dates can be used to tell the age of organic materials up to around 50,000 years.I understand calibration might have something to do with this, but then in the article it says in italicized words that the uncalibrated date “Must Always Be Mentioned”. CMI’s Dr Rob Carter responds: Anthony, As a fan of biblical archaeology, I was asked to address your question. W., 1993, A large drop in atmospheric 14-C/12-C and reduced melting in the Younger Dryas*, documented with 230-Th ages in corals: Science, vol. Establishment of a 7484-year chronology in the White Mountains of eastern-central California, USA. And uncalibrated dates are usually only off by less than 20%.But when I read articles about the results, they never mention the uncalibrated data, which could actually be correct. I am not an expert in every subject that impinges on the discussion, but I will do my best. But, lets be extremely conservative and say a 50,000 years old date is off by half.