Hi,
being totally invalid or off by a bit would mess with archeology
Can I just say that it doesnt even really mess with archaeology because 14c is never solely relied on to date anything in archaeology. It is always used as part of an overall body of evidence. If, for example, a 15th century BCE date was suggested by 14c dating of grain samples found on a particular 'floor', it would have to be supported by other things, such as pottery, jewellery, or even scarabs. The +/- 40 years deviance would also be considered, which many 'biblical archaeologists' are happy to ignore. The material to be dated also has to come from at least 3 different assays to check for reliability.
But c14 dating, although extremely useful, would never be taken as 'gospel' on its own by any archaeologist, it would need to fit in with the surrounding evidence.
As you know, 14c
IS extremely accurate, the techniques has been improved on time and time again, it is only certain people with a religous agenda who 'pray' that it isnt accurate. One thing that always makes me laugh is the c14 dating of grain at Jericho used by Fundy 'scholar' Bryant Wood to challenege Kenyon's 1550 dating of the destruction of Jericho. He totally ignores the +/- 40 years, he also used only one assay, and he doesnt address the fact that the British Museum published (in Radiocarbon Journal) that there had been a calibration error in the dating of a batch of samples that dated these samples 150 years earlier than they should be, and yes Wood's sample was in that batch! But, do the fundies then ignore Wood's dating here, nah. In a nutshell, fundies do think that c14 is reliable, but only when it gives a date that may support something in the Bible.
Brian.