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Wednesday, June 4, 2014

Concordance in meteorite dating: have I misunderstood Dr. Snelling?

I want to take a moment to clarify what I said in a recent post, Andrew Snelling concedes, radiometric dating of meteorites is solid, because I stumbled upon some confusion by popular YEC blogger Dr. Jay Wile. Amid comments beneath an unrelated post, Dr. Wile was directed to the link above, to which he responded:
"Not surprisingly, you are mischaracterizing Snelling on his discussion of meteorites. He never suggests that the radiometric dates of the meteorites is accurate. He only states that there is concordance... Accelerated decay would affect all isotopes in the universe, not just the ones on earth. As a result, it would be surprising if there weren’t concordance."
Presumably, by "you", Dr. Wile is referring to the author of the blog (me), rather than the kind person who linked to it. In any case, this sort of response ensures me that Dr. Wile never read beyond the title of the article. The meaning of my title is not that Snelling would openly admit to the accuracy of radiometric dating, but that he's finally run out of bad arguments with which to distract his readers and delved into the realm of 'so absurd, he may as well just tell them the truth'.

By admitting to concordance between multiple independent dating methods applied to meteorites, Snelling essentially has conceded the strongest evidence that radiometric dates for our solar system are accurate. He can pretend that an alternate explanation still exists, but as a lover of parsimony and progress, I will call the resignation when I see it.

So, I haven't mischaracterized Dr. Snelling on his discussion of meteorites. On the other hand, Dr. Wile has, in suggesting that "it would be surprising if there weren't concordance [between dating methods]." Dr. Wile strangely ignores the main 'hypothesis' of Snelling's article, which Snelling himself falsified thoroughly: accelerated nuclear decay should have affected each decay system to a different extent (depending on atomic mass and mode of decay), resulting in systematic discordance between the results. Snelling favored this explanation when it seemed to support his collection of dates from the Grand Canyon volcanics, and he devotes several plots in his most recent article to establishing that it cannot be applied consistently to extraterrestrial rocks. For this reason, Snelling relies on poor eisegesis of the Hebrew text to pull another rabbit out of the beaten hat and suggest that concordance of meteorites is a function of 'primordial creation chemistry'. I demonstrated why this ad hoc explanation would not work in my response to Snelling, which Dr. Wile dismissed without reading to maintain his reputation in the comment wars.

To accept Snelling rationalization, we'd have to assume that God rigged the isotopic chemistry of meteorites and other solar bodies, so that after X amount of accelerated nuclear decay, all solar bodies would only appear to be 4.56 billion years old, based on our knowledge of radioactive decay in the present. In such a scenario, we would expect extreme discordance among dating methods 1) if that arbitrary interval of radioactive decay were slightly shorter or longer (this doesn't work like a fast-forward button that controls only part of the universe), or 2) if modern decay rates were slightly faster or slower. Since God is the one fine-tuning the dials, it seems suspicious that he would choose the only setting that makes modern science appear successful, don't you think?

The mystery of discordance between radiometric dates for Grand Canyon samples vs. concordance of radiometric dates for meteorite samples is rather easily solved, and we need not invoke physical absurdities like accelerated nuclear decay. Samples from the Grand Canyon were collected and submitted for analysis by the RATE team; meteorite samples were collected and submitted for analysis by experts in the field of geochronology. In my review of some shady RATE team tactics, I highlighted the fact that Snelling and Austin chose highly altered samples for radiometric dating, despite their knowing full well how chemical/thermal alteration affects the model age of rocks. In other words, they attempted to rig the results. Closer inspection of their data, however, reveals that their results still supported the conventional age of Grand Canyon basalts, and no discordance really exists. A literature review of radiometric dates for Grand Canyon basalts since 1998 (when Snelling and Austin submitted their rigged selection) demonstrates that in the hands of experts, these rocks are dated consistently and precisely from one method to the next.

So which is it, Dr. Wile? Should we expect concordance or discordance between various methods of radiometric dating, and specifically why? What is the mechanism by which accelerated nuclear decay affects the U-Th and K-Ar systems by ~1–6 orders of magnitude (depending on where in the geological column the rocks are found), but the radiocarbon system by substantially less? Why do direct dating methods like U-Th and Ar-Ar, applied to single crystals, yield similar results as isochron methods like Pb-Pb, Sm-Nd, Lu-Hf, Rb-Sr, applied to multiple crystals? Why should we expect noble-gas daughter products within the U-series and K decay systems to remain trapped in the crystal structure, despite radioactive decay so intense that it could melt the whole rock?

Can accelerated nuclear decay explain the model ages of 'post-Flood' features like caves and Quaternary marine, lacustrine, and glacial sediments, which are dated at thousands to hundreds of thousands of years by a combination of radiocarbon, U-series disequilibrium, OSL, and TL methods? Of course not. Accelerated nuclear decay is nothing more than a copout, like a bottle of whiteout to erase any contrary evidence to the young-Earth paradigm. It is entirely ad hoc and lacks any physical/theoretical framework. Above all, it makes no testable predictions in real-world data. Therefore, it is below pseudoscience, which at least tends to offer arguments that sound plausible.

Many years ago, Dr. Wile posted that he gave into the notion of accelerated nuclear decay only "kicking and screaming", because he sincerely didn't want to believe that half-lives of radioactive nuclei could change. Along with Russell Humphreys' failed helium-diffusion study, Dr. Wile cites as convincing evidence a handful of papers demonstrating that under extraordinary circumstances (such as heating tritium after absorbing it onto 15-nanometer particles of titanium to invoke nuclear pairing of 3He atoms, or burying polonium inside copper metal and dropping the temperature nearly to absolute zero), the radioactive decay constants can change by a few percentage (in most cases) to as much as 300% for one short-lived, heavy isotope. As a nuclear physicist, Dr. Wile knows well that these studies have nothing to do with the science-fiction claims of the RATE team. He knows just as well that Russell Humphreys' modeling of helium diffusion in zircons fares no better, in particular because the claim is falsified by every single application of (U-Th)/He thermochronometry since the inception of the RATE team. Therefore, I do not perceive Dr. Wile as one kicking and screaming, brought in only by a wave of evidence, but as one looking actively for excuses not to trust it.



10 comments:

  1. Jon

    My initial reaction - BEFORE reading your new post - is that the Conclusions section to the Snelling paper (referenced in your earlier blog and discussed in comments under a recent Wile blog) included the following sentence: "There is no doubt that after decades of numerous careful radioisotope dating investigations of the Allende CV3 carbonaceous chondrite meteorite that its Pb-Pb isochron age of 4.56718 ± 0.0002 Ga has been well established" (he tries to explain this away).

    Incidentally I have tried to comment a couple of times under the Wile blog (and also did so at the latest Naturalis Historia post - before realising that Joel had already responded to criticisms against him by Wile).

    As a non-chemist, non-palaeontologist and non-geologist I have to say my brain seized up when reading the very latest comments under the Wile blog ...

    Ashley H-R

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  2. PS The first of my two attempted comments to Jay Wile (awaiting moderation) reads:
    "J Wile

    You boldly claim in a comment above: “The vast majority of the evidence points to a young earth”. Yet all I get when I click on the link is THIS blog post about soft tissues.

    This person convinced of a very ancient Earth and even more ancient universe is somewhat puzzled.

    Incidentally Questioning Answers in Genesis (non YEC Christian) has blogged again."

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  3. PPS
    The Wile link is in fact to his HOME page (the soft tissue article appears because it is his latest article).
    But he does NOT link to any SPECIFIC article which seems a bit lazy if nothing else,

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  4. Thanks for the response to Dr Wile, and apologies if I inadvertently stirred up some trouble by linking your post and Joel's one to his. I was hesitant to press further the MASSIVE issues with millionfold increases in decay rates (if thats even possible, as you so eloquently explained here) because I am a layperson in these fields.

    It should be noted that the YEC conclusions raise massive theological problems as well, a God who stretches spacetime to make stars appear millions of light years away and deliberately accelerates nuclear decay rates seems to be deliberately doing so to misle human efforts to determine reliable ages. This bears all the hallmarks of a deceitful and capricious God.

    Off topic, I made a post on the problems of designed/created beings that may also apply to the theory of YEC special creation and intelligent design a while back.

    http://reformingthehereticalmind.blogspot.com/2014/06/are-these-intelligently-designed.html

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    Replies
    1. Thanks for the link, I'll be sure to read and comment!

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  5. P.S again, thank you very much for this blog. It has been very informative.

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  6. Jay Wile at Proslogion is (at the discussion of his recent post about soft tissues) accusing the above blog post of "relying on Ad hominem attacks". I have attempted to reply as follows (it awaits moderation):
    "You do not appear to be engaging with the SUBSTANCE of the comments by Questioning Answers in Genesis. Something I have seen many times from young earth creationists."

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    1. Well, I do draw some conclusions about his personal attitude toward the evidence, but it's by no means an attack. In any case, deferring criticisms by attributing them to ad hominem attacks is a fairly good indication that one finds no substantial reason against those criticisms. It should be clear to anyone here that my arguments do not rest on Dr. Wile's personal competence/convictions. It matters not how smart or kind he is; he is still wrong about the expectation of geochronological concordance in the realm of 'accelerated nuclear decay'.

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  7. Since Wile is still banging on about you using Ad hominems (only) I have just submitted the following response (awaiting moderation):
    "Well here is that Questioning Answers in Genesis post. People can judge whether he is relying solely on Ad hominems and whether it is him or you or both who are ignoring substance:
    http://questioninganswersingenesis.blogspot.co.uk/2014/06/concordance-in-meteorite-dating-have-i.html

    It is very clear to me that you have yet to comment in detail here on Baker's new post."

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