keskiviikko 15. huhtikuuta 2015

Timantti, YEC kreationistin paras ystävä?

Jonathan Sarfati on nuoren maan kreationistien (Young Earth Creationist YEC) johtavaa joukkoa. Hän kirjoittaa timanteista hauskasti otsiokoidussa artikkelissa
Diamonds: a creationist's best friend 
Radiocarbon in diamonds: enemy of billions of years

Ajatus on yksinkertainen ja tehokas: jos kerran timantti on miljardivuotta vanha ja koska radioaktiivinen hiili-isotooppi C 14 puoliintuu 5700 vuodessa, luonnon timanteissa ei pitäisi olla sitä jäljellä lainkaan.

Sarfati viittaa sitten mm. geofyysikko John Baumgardnerin mittauksiin, jossa timantissa on havaittu 10x oletettua korkeampi määrä C14.

Rotta, R.B., Evolutionary explanations for anomalous radiocarbon in coal? Creation Research Society Quarterly 41(2):104–112, September 2004. 
Baumgardner, J., Humphreys, D., Snelling, A. and Austin, S., The Enigma of the Ubiquity of 14C in Organic Samples Older Than 100 ka, Eos Transactions of the American Geophysical Union 84(46), Fall Meeting Suppl., Abstract V32C-1045, 2003. 
 Lowe, D., Problems associated with the use of coal as a source of 14C free background material, Radiocarbon 31:117–120, 1989.

John Baumgardner
Wikipediassa on artikkelin perustana olevan tri Baumgardnerin esittely, joka alkaa lauseella 
"John R. Baumgardner is a geophysicist, young earth creationist, intelligent design supporter and Christian." 
Artikkeli kertoo, että hän oli Ron Wyattin mukana Noan arkkia etsimässä, mutta sanoi että "löydetty arikki" onluonnonmuodostelma. 
In 1997, US News and World Report described him as "the world's pre-eminent expert in the design of computer models for geophysical convection"

Kirk Bertsche on kirjoittanut vastineen, josta laitan timantteja koskevan osan tähän kiinnostuneille

Rate project
 The ICR (Institute for Creation Research) recently spent eight years on a project known as RATE (Radioisotopes and the Age of The Earth). The RATE team claims the results have yielded convincing and irrefutable scientific evidence of a young earth.
    John Baumgardner, a geophysicist with expertise in tectonic modeling, presents experimental data claiming to show that all biological material contains intrinsic radiocarbon, no matter how old that material may be thought to be [1, 2]. He makes additional claims that even non-biological carbonaceous material contains intrinsic radiocarbon. He suggests that this radiocarbon is residual from the material’s creation. If true, his claims would have far-reaching implications for the ages of these materials.
    Baumgardner presents two classes of data. The first is a set of 90 previously published radiocarbon AMS dates of old samples (most >100k years) that he has re-analyzed. The second is a set of new samples that the RATE team collected and sent to a leading radiocarbon AMS laboratory to be dated. In both cases, I am convinced that the “intrinsic radiocarbon” is nothing more than contamination and instrument background.
    Diamond is difficult to combust. The RATE samples apparently required modifications to the normal procedure [1], presumably higher combustion temperatures and longer combustion times, likely increasing the sample chemistry contamination. The samples were reportedly pitted and may have been subjected to previous analyses and to unknown contamination. Nevertheless, RATE’s five deep-mine diamond samples had radiocarbon levels only slightly above background (0.01 to 0.07 pMC after background subtraction), while the seven alluvial samples ranged from 0.03 to 0.31 pMC after background subtraction.
    Subsequently, the RATE team inserted diamond directly into an ion source, eliminating the sample chemistry, and measured much lower radiocarbon values, “between 0.008 and 0.022 pMC, with a mean value of 0.014 pMC,” apparently with no background subtraction [6]. This much lower value for unprocessed diamond provides strong evidence that their processed diamond samples had been contaminated, most likely by the modified sample chemistry.
    Taylor and Southon have also measured unprocessed diamond, finding a similar range of 0.005 to 0.03 pMC without background subtraction. They interpret this result as their instrument background, primarily due to ion source memory. Their ion source current varied, unintentionally, over about a factor of two, perhaps due to crystal face orientation or to conductivity differences between samples. “The oldest 14C age equivalents were measured on natural diamonds which exhibited the highest current yields” [4]. This important observation provides evidence about the source of the radiocarbon.
    If the radiocarbon were intrinsic to the sample, there would be no change in the radiocarbon ratio with sample current. The 14C, 13C, and 12C would change in unison. However, if the radiocarbon were coming from ion source memory or elsewhere in the accelerator, it should give a count rate independent of ion source current. Normalizing the radiocarbon count rate to the ion source current, which is predominantly 12C, would result in higher radiocarbon content for lower source currents, as observed. This data provides clear evidence that at least a significant fraction of the radiocarbon detected by Taylor and Southon in diamond measurements did not come from the diamonds themselves and thus could not be “intrinsic radiocarbon.”
    The lower values for unprocessed diamond and the current-dependent behavior find no explanation in Baumgardner’s “intrinsic radiocarbon” model. But these results fit well with the Taylor and Southon evidence that instrument background (specifically ion source memory) is material-dependent, with diamond exhibiting significantly less ion source memory than graphite. The radiocarbon detected in natural, unprocessed diamond measurements seems to be nothing more than instrument background.

Kirk Bertsche
Dr. Bertsche received a PhD in Physics from the University of California, Berkeley in 1989 under the direction of Prof. Richard A. Muller, the inventor of radiocarbon AMS. Dr. Bertsche’s thesis involved the design and testing of a small cyclotron for radiocarbon AMS. He subsequently received a postdoctoral appointment in the AMS laboratory of Lawrence Livermore National Laboratory, where he was involved with accelerator design and operation and also with sample preparation and analysis. In 2005, he received an MA in Exegetical Theology from Western Seminary, Portland, Oregon. He is the author of 25 publications and 13 patents, primarily dealing with particle accelerator and electron microscope design.

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