[extropy-chat] Addwaita:250 years is a long time.

[Robert Bradbury]

To start this conversation out on some "firm" ground (Mike/Spike) I went
back to Wikipedia [1], and looked up Carbon-14 dating [2] -- it discusses
the fact that C-14 dating is based on two different half-lives (Libby &
Cambridge) which have error ranges of 30 & 40 years respectively.  So
question #1 would be whether if one scales the half lives (5568 & 5730)
years down to ~200 years how much resolution does one lose?  Question #2
would be how accurate are current mass-spec machines with respect to
counting C-14 atoms?  Question #3 would be how much actual C-14 is there in
any remaining "static" components of now dead tortoises?  I think this may
be the point spike was trying to make.  If the body's are in constant flux
with the atmosphere then the C-14 is balanced -- so red blood cells produced
in the last few months are going to reflect the C-14 in the current
atmosphere.  But portions of the skeleton, teeth (which I'm not sure
tortoises have), and perhaps the shell may contain C-14 from when the animal
first started depositing those structures.

So for example, if I do C-14 dating from the central rings of "my" tree they
should come out as much older than the C-14 dating of the outer rings of
"my" tree because the carbon was fixed long ago.  Of course tree-ring dating
is relatively precise since the trees essentially have to grow every year.
With animals it is a different story.  Teeth are static (except in species
such as sharks and elephants where they are replaced), bones are open to
debate and shells as I have recently learned may fall into the bone category
(in that they can suffer injury and be repaired).  Unless one knows the
turnover rate for various components of the organism and the environmental
conditions (which may limit turnover rates) it may be very difficult to
estimate what fraction of the carbon in a sample is "from the beginning" and
what fraction is "recently deposited".

Also, as a side note -- I have read that Addwaita was cremated (this is
presumably typical for India yes???).  (Raises all kinds of questions -- how
can one be cremated and C-14 dated???)  What an unextropic end.  :-(  A
brain with potentially hundreds of years of memories being subjected to
molecular decomposition.

Brings up lots of questions about downloading... I wonder what it was like
to live in Lord Robert Clive's garden?  Now I may never know...

Robert
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1. In case people missed it, today's Wikipedia's featured article is about
"Noah's Ark" :-)
http://en.wikipedia.org/wiki/Noah%27s_Ark<http://en.wikipedia.org/wiki/Noah%2527s_Ark>
which lends itself to all kinds of discussion about "popular" mythology
(doctrinal vs. anecdotal) etc. somewhat related to "How old are the oldest
tortoises?"
2. http://en.wikipedia.org/wiki/Carbon_14_dating
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