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From: jho@ihu1m.UUCP (Yosi Hoshen)
Newsgroups: net.origins
Subject: Re: The Scientific Case for Creation: (Part 32)
Message-ID: <517@ihu1m.UUCP>
Date: Wed, 17-Jul-85 09:15:15 EDT
Article-I.D.: ihu1m.517
Posted: Wed Jul 17 09:15:15 1985
Date-Received: Thu, 18-Jul-85 08:13:44 EDT
References: <386@iham1.UUCP> <62@uw-june>
Organization: AT&T Bell Laboratories
Lines: 29

> >       60.  Radiocarbon dating, which has been  accurately  calibrated
> >            by counting the rings of living trees that are up to 3,500
> >            years old, is unable to extend this accuracy to date  more
> >            ancient  organic  remains.  A few people have claimed that
> >            ancient wood exists which will permit this calibration  to
> >            be  extended  even  further back in time, but these people
> >            have not let outside scientists examine their data.
> 
> This is a serious charge, and if true, is very disturbing.  Can anyone
> offer substantiation?

The creationist are trying to confuse the issues.  The half life of
carbon 14 is few thousand years, therefore, it is not useful for
dating objects on a prehistorical scale.  Evolution time scales
are order of magnitude larger.  I don't see the point of bringing
carbon dating into the discussion unless you are trying to confuse 
the uninformed. 

Returning to the point of the accuracy of the technique.  The rate of decay
of radioactive isotopes does not vary with time.  The problem is
the rate of formation of the isotope.  Carbon 14 is formed constantly
in the atmosphere by cosmic ray bombardment of nitrogen (I think).
We cannot assume that the bombarment has been constant throughout
the ages.  (Radioactive decay is an intrinsic property of a single
atom,  whereas cosmic rays intensity depends on a collection of
many sources that could be changing with time.)
-- 
Yosi Hoshen, AT&T Bell Laboratories
Naperville, Illinois,  Mail: ihnp4!ihu1m!jho