Radiometric dating uncertainty
This tendency to decay, called radioactivity, is what gives radiocarbon the name radiocarbon.
(This, in turn, is caused by variations in the magnetic fields of the earth and sun, for example.) Although the ratio of radiocarbon to stable carbon in the atmosphere has varied over time, it is quite uniform around the globe at any given time because the atmosphere mixes very quickly and constantly.
Plants obtain all their carbon atoms from the atmosphere.
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.
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.
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.