Posted by Marvin Amstey on June 23, 1999 at 15:27:03:
In Reply to: Re: Sources of error in Carbon-14 dating? posted by James Allen on June 23, 1999 at 11:57:36:
: : Dear Steve,
: : Nearly all living organisms absorb C-14 from the atmosphere in such a manner that there is a direct correlation between atmospheric C-14 and the amount in the organism. Radiocarbon dating measures the decay of C-14 following the death of the organism.
: : One difficulty in the calibration of the rate of decay is that atmospheric C-14 has not, and does not, remain absolutely constant. Hence, a line illustrating the decay will appear as a slope with irregular spikes - particularly for relatively recent periods.
: : During the testing process, measurement of beta radiation from the organism is within certain tolerances. If you visualize those tolerances as two parallel, horizontal lines which intersect the jagged slope of the decay, you will find that there could be several points of intersection - depending on whether the organism lived during a period when atmospheric C-14 remained constant or during a period of these spikes.
: : The various dates and variables which you read are verbalizations of the graph of the measurement and the decay. It isn't easy to understand. In April, Jurg Rageth spent about 2 hours explaining it to me.
: : Regards,
: : Wendel
: Wendel explained the problem nicely. The problem didn't go away however and people in public positiond with the publics trust still must aquire textiles from "dealers" at very high costs and C-14 done by somebody trusted is how the million dollar decisions are made. The C-14 results are the final piece in a puzzel which addressed iconography, fiber analysis, dye analysis, and incredibly detailed structural analysis. When everything is a go the last question is , "are we being fooled on the age", and it is here a mans' word, like AJT JUlls', becomes invaluable. People have never grapsed the importance of the fact that HE ,working on a project for the MET, dated a Turkoman chuval , twice, to a mean date of 1650. The case was closed years ago when this news broke in academic circles that true classical age Turkomen weaving did in fact exist. You are wasting time arguing about whether or not they exist, they do, the question is who has them. Jim Allen
I don't think anyone argues with the fact that 18th and 17th century Turkomen pieces exist, we're just arguing - and I side with the disbelievers - that c14 dating is the way to prove it scientifically. At the moment, I'd rather accept "old" as defined by color, wool quality, drawing and handle. Regards, Marvin
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