Re: Egyptian Chronology

From: Eric Stevens (eric.stevens_at_sum.co.nz)
Date: 11/16/04 

Date: Wed, 17 Nov 2004 10:02:40 +1300

On Tue, 16 Nov 2004 07:59:04 GMT, Kendall K. Down
<webmaster@diggingsonline.com> wrote:

>In message <cb1ip0l9bjemumu33tp8n8jenb0nmv7kcp@4ax.com>
> Eric Stevens <eric.stevens@sum.co.nz> wrote:
>
>> Not so. It is known that assuming the ratio of atmospheric C12/C14 has
>> always been constant is incorrect and will lead to errors if samples
>> are dated on that basis of that assumption. The only way to get over
>> this problem is to work backwards and determine the C12/C14 ratio for
>> an object of known age. It is possible from this to determine the
>> C12/C14 ratio at the time the object was formed. The standard Libby
>> decay curve can then be adjusted to take the original ratio into
>> account. There is nothing circular about this process.
>
>What is circular is using C-14 dating to determine a dendrochronlogy
>sequence, then using the sequence to clarify C-14 dating.
>

You are quite right. That would be circular if that was what was done,
but its not.

Someone finds a piece of wood which, by means of ring counting, the
determine is (say) 1287 years old. They remove a small sample of that
wood from 1287 year ring and determine its C12/C14 ratio. They compare
that measured ratio and compare it with the theoretical ratio from the
Libby decay curve. The difference is used to establish a correction
factor for 1287 years ago.

Eric Stevens

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