Posted by Craig Carriere on June 22, 1999 at 18:51:49:
In Reply to: Re: Sources of error in Carbon-14 dating? posted by Erol Abit on June 22, 1999 at 14:36:45:
C-14 has a number of potential sources for error; in terms of textile dating one of the greatest problems with it is the lack of an accurate absolute measure of the date. C-14 data are compared to a "known" standard curve that is obtained from tree ring data. From prehistoric times up until the 1600-1700 the decay of C-14 levels with time was a roughly linear relationship. At the beginning of the industrial revolution the C-14 levels spiked and then began to decay again up to the 1940s and the start of the nuclear testing programs which caused another spike in the C-14 level. Due to the non-monotonic decay of the C-14 level with time over this period it is impossible to date any material accurately using C-14. The claims of 1600 or 1700 dates using C-14 are done by ignoring this phenomenon and accepting the earliest date. Although design factors in the weavings might make one argue against a 20th century dating C-14 by itslef can not accurately date any material reliably past 1500-1600.
Craig