[LMB] OT: Turin test
mtraber251 at earthlink.net
Sat Sep 10 03:18:17 BST 2011
On 9/9/2011 11:35 AM, phoenix at ugcs.caltech.edu wrote:
> On Fri, Sep 09, 2011 at 07:23:44AM -0400, mtraber251 wrote:
>> I have issues with some applications of carbon 14 testing, but it is
>> a materials handling issue ...
>> Look - when you are testing a textile that has both gone through a
>> *major* fire, with commensurate damage, *and* spent centuries hung
>> in buildings lit by flames, censored with incense, wafted through
>> environments filled with tobacco smoke in various forms, and
>> breathed upon by numerous handlers there *is* going to be
>> *contamination* no matter how you look at it.
>> I am not claiming that the Shroud of Turin is real, or not. I am
>> just saying that the test may have been screwed. I find that there
>> is reasonable doubt as to the accuracy of that particular test.
> If only the testers had thought of such contamination issues and done
> cleaning of their sample.
> "Because it was not known to what degree dirt, smoke or other
> contaminants might affect the linen samples, all three laboratories
> subdivided the samples, and subjected the pieces to several different
> mechanical and chemical cleaning procedures.
> All laboratories examined the textile samples microscopically to
> identify and remove any foreign material. The Oxford group cleaned the
> samples using a vacuum pipette, followed by cleaning in petroleum ether
> (40° C for 1 h) to remove lipids and candlewax, for example. Zurich
> precleaned the sample in an ultrasonic bath. After these initial
> cleaning procedures, each laboratory split the samples for further
> Three different labs, each trying different cleaning treatments, and
> also comparing against control samples of known dates.
> Top Google hit for [carbon-dating shroud of turin], BTW.
> -xx- Damien X-)
And speaking as a hazmat tech and NDT boffin, elemental contamination is
a bit more difficult to deal with than hosing it off, soaking it in more
chemicals or airing it out...and C14 is an elemental contamination. It
can modify any organic bonding of C12 or C13.
C14 testing is not the all that that people think it is. Especially when
the sample is contaminated out the wazoo. It *is* good for testing
something that has been shut up in a tomb for the past few thousand
years and *not* cross contaminated for 500 years of public exposure.
[not to mention some people are claiming that they C14 tested a
relatively modern patch that was french woven in along the edge instead
of original material, but we are not going into that...]
More information about the Lois-Bujold