[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

orion Radiocarbon dating


Dear orioners:
Rather than respond in detail to Sigrid Peterson's lengthy comments 
on radiocarbon, I will make a brief observation and then offer some 
resources which may be useful.  (Two radiocarbon web site addresses 
worth getting are at the bottom of this for those in a hurry.)

I don't know whether there has been a gap in my education, or the 
synapses just aren't firing today, but I honestly cannot understand 
what Sigrid is talking about in some of the post, the jargon and the 
logic.  However what I do understand, in essence, is that there is an 
objection to interpreting radiocarbon dates differently after the fact, 
Now I can understand objections to my arguments on pPs(a).  I gave 
it a "question mark", on radiocarbon grounds independent of my 
dating theory, which I explained--the same evaluation I would give 
that pPs radiocarbon date if I had no scrolls dating hypothesis at 
all.  Then I made what seemed to me the logical step of 
saying that a question mark is not a falsification.  Some may see 
differently; that's fine.  But I was offering my explanation and 
interpretation of the data, and trying to be clear and honest about 
what I was doing. 

But so far as I can tell, Sigrid isn't objecting to a particular 
argument concerning my interpretation of pPs(a).  She is making a 
method argument against any selective questioning, or weighting, 
of data at all.  Now this is on its face absurd.  Real data is messy.  
The data involves margins of error and scientists work hard to defeat the 
sources of tiny errors that can throw a date off.  To say that a date 
that comes out at one end has the same weight as a date that agrees 
with well-established patterns is nonsense.  Its all data, yes, in 
the sense that you want to find out why something unusual got 
reported, because there could be something interesting there.  But 
this is nct like biblical inerrancy where one has to believe all or 
nothing.  Both the Atiqot reports on the Zurich and the Tucson 
labs reported, then interpreted the data; in each case a real, 
reported data item was questioned, and to most, rejected, because 
it was out at one or the other end more than the others.  (So I 
wonder why Sigrid is picking on me!)    

To date an archaeological terminus assemblage (and the Qumran texts 
are an analogy, in having some fixed latest date for all of the 
texts--that is our assumption), some of the 14C dates are 
going to spill over a little later than the actual date of the destruction 
level.  One cannot simply take the latest single measured 14C date 
and say, "you must accept this, or else".  All archaeological sites 
would get misleadingly late dates from radiocarbon batteries by 
this method.  You have to discount, or set aside, a few small 
number of dates at one end to arrive at a realistic estimate for 
the true date of the terminus.  

But I do not wish to continue, and orion readers may cheer this 
sentiment also  :-)   Many of these issues and questions will be 
better understood by some resources which will explain this 
fascinating, but sometimes paradoxical matter of radiocarbon 
dating, as well as giving a better idea of what labs do and 
what it is all about.
       
             The best (have your bookstore order a copy): 
            Sheridan  Bowman, _Radiocarbon Dating_, British Museum, 1990, 
            only 64 pp but is succinct, clear, accurate, and has it all.  
            
            Also: 
           M. J. Aitken, _Science-based Dating in 
              Archaeology_, 1990

            R. E. Taylor, _Radiocarbon Dating_, 1987.

And two excellent web pages, both loaded with information:  

           (New Zealand)
           http://www2.waikato.ac.nz/c14/webinfo

           (Oxford's famous radiocarbon lab)
           http://www.rlaha.ox.ac.uk

Greg Doudna
Copenhagen