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Ouch! Carbon dating flawed too!
Posted: Thu Sep 11, 2008 2:17 pm
by Rokcet Scientist
Research Finds Carbon Dating Flawed
September 10, 2008
New research funded by the National Science Foundation at the University of Miami is showing that carbon dating (the 13C/12C ratio used to infer age) in the ocean can only be trusted up to 150 million years ago. From the primary researcher, 'This study is a major step in terms of rethinking how geologists interpret variations in the 13C/12C ratio throughout Earth's history. If the approach does not work over the past 10 million years, then why would it work during older time periods? As a consequence of our findings, changes in 13C/12C records need to be reevaluated, conclusions regarding changes in the reservoirs of carbon will have to be reassessed, and some of the widely-held ideas regarding the elevation of CO2 during specific periods of the Earth's geological history will have to be adjusted.' While this research doesn't necessarily throw carbon dating out the window, it should cause people to rethink so many theories about early life that revolved around ages of sediment in the oceans.
http://www.sciencedaily.com/releases/20 ... 104202.htm
Posted: Thu Sep 11, 2008 2:30 pm
by Minimalist
carbon dating (the 13C/12C ratio used to infer age) in the ocean can only be trusted up to 150 million years ago.
That won't do Arch any good. Anything over 12,000 years kills his theory.
Posted: Fri Sep 12, 2008 2:10 pm
by kbs2244
I thought the standard limit on vaild C14 dating was agreed to be 40K to 60k BP
Posted: Fri Sep 12, 2008 2:41 pm
by Minimalist
Right. This article is about C13 and C12.
Posted: Sat Sep 13, 2008 9:50 am
by kbs2244
Yes, I understand.
But isn't the basic concept the same?
Does the problem transfer?
Posted: Sat Sep 13, 2008 11:52 am
by Minimalist
I don't know. C12 is not radioactive but C13 is. I'm not sure what the half-life of it might be.
Carbon 12
Posted: Sat Sep 13, 2008 1:22 pm
by Cognito
Alright guys, Carbon 12 is incredibly stable. The article has nothing to do with Carbon-14 dating (that isotope has an agreed upon half-life of 5,730 years). The Carbon 12/13 ratio is used to get a "thumb in the air" idea of the age of geological formations, but we're talking many millions of years. Refer to this:
http://en.wikipedia.org/wiki/Carbon
Since Carbon-14 has such a short half-life and since it is included in organic materials such as human bones, wood, other plant material, etc. it is very useful for dating items in the recent geological record. However, the danger is thus:
a. 1/2 of C-14 in sample remaining by 5730ya (3,722bce)
b. 1/4th of C-14 in sample remaining by 11,460ya (9,452bce)
c. 1/8th of C-14 in sample remaining by 17,190ya (15,182bce)
d. 1/16th of C-14 in sample remaining by 22,920ya (20,912bce)
e. 1/32nd of C-14 in sample remaining by 28,650ya (26,242bce)
You get the idea.
The outlier for dating anything by C-14 is 50-60,000 years ago. Even at that, there can be wild variation in older samples due to the infinitely small C-14 remaining. This is further complicated by the fact that carbon in the atmosphere varied during the early Holocene and late Pleistocene for a variety of factors - after all, we were just finished the latest and most severe ice age on the planet at about 9,600bce (termination of the Younger Dryas).
Al Goodyear pulled a "sleight of hand" when dating the Topper Site to 50,000 years ago. He only went as far as the exhaustion of C-14 in his samples. His thermoluminescence dating will show the site to be older, but nobody is ready for a date earlier than 50,000 since it requires a hominid different than HSS according to conventional wisdom.
As Jack Nicholson said:
"You can't handle the truth!!" 
Posted: Sat Sep 13, 2008 1:36 pm
by Minimalist
but nobody is ready for a date earlier than 50,000 since it requires a hominid different than HSS according to conventional wisdom.
I can just hear The Club shrieking now.
Posted: Sun Sep 14, 2008 3:46 am
by Rokcet Scientist
but nobody is ready for a date earlier than 50,000 since it requires a hominid different than HSS according to conventional wisdom.
Of course! That's our old boating globetrotter HE! HE conquered the world. Via Asia (Java, China). If he could do
that, then it makes sense that he probably kept on walking/boating, and also got to the Americas! Loooong before HSS was even a blink in his eye...
50,000 BP?
That's peanuts!
If HE did get to the Americas, then he probably did that (looong)
before HSS' OOA diaspora(s). The 2 major waves of which have been dated around 72,000 BP and 112,000 BP, if I remember correctly.
Posted: Sun Sep 14, 2008 12:20 pm
by kbs2244
OK, so the C14 problems do not transfer from a technical point of view.
But if C12/13 is now thought to good to only 150MM BP, what does this do to previously dated sites?
Do we have a need to re-date like we discussed when C14’s problems appeared?
Redating
Posted: Sun Sep 14, 2008 2:01 pm
by Cognito
Do we have a need to re-date like we discussed when C14’s problems appeared?
Probably just a good tweaking as analysis gets better. Dates that old are only a good SWAG at best in the first place.
Posted: Sun Sep 14, 2008 3:07 pm
by Digit
As an engineer I am aware that all measurements are against an agreed reference. How the hell do calibrate some thing like that?
Roy.