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Re: orion AMS dating

On the date of deposit of the scrolls and 14C, some comments.
     1) S. Goranson is correct to take the 14C seriously.  I am concerned
that 14C, which is hard science, is being relegated to less 
importance in contrast to what is believed to be a "better"
system of dating, the palaeographic datings which claim greater
precision but should be considered in the genre of educated
guesses, not hard science, since they were created in the absence of
a single internally-dated text in all of Palestine for the 200-year
period 150 BCE-50 CE as control or comparison.  There are
some features of 14C, particularly the calibration curve wiggles,
which are very hard to understand, but the information there, if
properly understood, is real.  
     2) The date of deposit is utterly fundamental to interpretation 
of the Qumran texts' significance and is too important an issue to 
deal in "probablies" or plausibilities.  On structural issues of this 
importance, a binary distinction between "certain" and "uncertain" 
would be useful in classifying specific conclusions.
     3) When we see the bars representing 14C date ranges it is natural
to think the most probable date is somewhere in the middle, tapering
off toward the ends.  This is not, repeat, IS NOT, a useful or valid
assumption for carbon dates.  There is not space to explore this in
an email post, but this is coming from hundreds of hours of analysis
and expert discussions, including at an international radiocarbon conference 
in Groningen five weeks ago which I attended.  The paradox is that the
true date can be anywhere on that spectrum.  The spectrum gives
possibilities.  If one possibility is at one end and two others are at 
the other end (and the bar covers both ends), it is not correct to
look at "the middle".  Nor is it correct to say that the two possibilities
add up to more probability than the one.  Common sense tells us 
to think this way, but common sense is wrong in this case.  
The only way to exclude either end is through bringing in outside 
information (such as other carbon dates on closely comparable items,
and look at the overlaps).
     (4) There is a sharp drop in the calibration curve between 65 BCE 
and about 40 BCE.  Existing 14C scrolls data (as Goranson indicates) 
appears to argue against an a quo date earlier than c. 50 BCE, 
slightly later than the 63 BCE date.      
     5) If three assumptions are accepted further information becomes 
available from 14C data.  1, that texts found at Qumran written in the 
same type of palaeographic scribal hand were written within 50 years 
of each other.  2, that the earliest (4QTQahat) and latest (4QpPsA) 
carbon dates are excluded as outliers.  3, that except for the two outliers, 
all other radiocarbon dates are accurate within reported error margins, 
then . . . given the validity of these three assumptions 14 C data gives 
dates in the 1st BCE for all "hasmonean" and "herodian" scribal hands, 
and there is little statistically significant date difference between 
the two.
     Greg Doudna