3. Results and discussion The conversion of 40K to 40Ar by electron capture has been widely adopted to date geological events (e.g., [9-11]). If the effect of pressure on the decay rate of 7Be observed in the present study also occurs in 40K, and K-containing minerals were subjected to high pressure during their geological history, the ages of these materials determined by the conventional dating method might be overestimated. However, since the λ of 7Be increases by about 1% at 400 kbar, it would be expected that a similar effect on larger nuclides such as 40K would be smaller. We would like to note here that, following our experiment on 7Be, another experiment was performed on 83Rb, a much bigger nuclide undergoing electron-capture decay. For a nuclide of this size, no measurable changes were observed up to 420 kbar at room temperature.
Full pdf at link.
So we still have less than 1% variation. Much less than what is necessary to turn 4.55 billion years into 6000.
Aren't some of the other occurrences involving minor variances in gamma decay?
Anything that affect Uranium and Thorium? (ie α & β decay)?
No, we have evidence of essentially constant decay rates for significant periods of time, constant enough that age calculations are not affected.
For some nuclei, including some of the ones used for dating, Yes. And there is also the consillience with non-atomic dates to consider as well.
40k - > 40Ar is electron capture. I don't know if all electron captures are the same.
If you mean with respect to sensitivity to pressure, then no, they are not all the same.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
I have never met a man so ignorant that I couldn't learn something from him. Galileo Galilei
If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass
So we still have less than 1% variation. Much less than what is necessary to turn 4.55 billion years into 6000.
Yes. But the point was merely to show that not all decays are affected in the same way external processes. I can cite an extreme example that we've discussed in these fora before:
quote:A 1996 paper discusses this bound-state decay of bare-nucleus rhenium-187. Whereas neutral rhenium-187 has a half-life of 42 × 10^9 years, the authors measured fully ionised rhenium-187 to have a half life of just 33 years! They discuss the cosmological implications of the altered half life of rhenium-187 in various degrees of ionisation in stellar interiors, and what that implies for our knowledge of galactic ages.
But even this particular example is not really the point. Which is that speculating on how an unknown mechanism might or might not operate on different nuclei in similar ways, or speculating on whether the effect might be amplified under certain conditions is not really an air tight argument.
Edited by NoNukes, : No reason given.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
I have never met a man so ignorant that I couldn't learn something from him. Galileo Galilei
If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass
quote:This is actually a non-issue for the diamonds in the Baumgarder experiments as those turned out not to have any C-14 in them at all.
I did not see a citation for your above statement. I assume it is in regards to instrument background. Here is the following research refuting background C-14 as being a reasonable objection to detected amounts of C-14 in diamonds.
Despite the conflict it raises for Bertsche’s worldview, the Taylor and Southon paper tangibly strengthens the case that AMS instrument background can be eliminated, to a high degree of certainty, as a viable explanation for the substantial 14C levels measured so routinely in carbon-bearing samples from deep within the geological record. http://johnhartnett.org/...carbon-14-in-diamonds-not-refuted
The conclusion affirms C-14 in unusual high amounts in diamond samples.
Here are diamond fragments measured for calibration... note the ages.
Six fragments cut from a single diamond exhibited essentially identical 14C values – 69.3 ± 0.5 ka–70.6 ± 0.5 ka BP. The oldest 14C age equivalents were measured on natural diamonds which exhibited the highest current yields. http://www.sciencedirect.com/...rticle/pii/S0168583X07002443
Your citations would be appreciated if you want to dispute the findings further.
This is actually a non-issue for the diamonds in the Baumgarder experiments as those turned out not to have any C-14 in them at all.
I did not see a citation for your above statement
Try Bertsche and thre previous messages in this thread.
From your reference:
quote:Note that the authors emphatically do not attribute the higher 14C counts, as Bertsche claims, to ion source memory contamination.
Bertsche mentioned ion source contamination and several other possibilities for the results. Baumgardner fail.
quote:The simplest explanation for the trend in the eight samples in part B is that it is associated the presence or absence of the silver powder. Precisely how the silver powder might be producing the observed trend is not clear
Now there's a knee-slapper! Both the presence and absence of silver powder cause the effeect, therefor the effect is caused by silver powder!
I'm getting a copy of the Taylor and Southon paper. Bet Baumgardner's misrepresenting it.
Here are diamond fragments measured for calibration... note the ages.
quote:Six fragments cut from a single diamond exhibited essentially identical 14C values – 69.3 ± 0.5 ka–70.6 ± 0.5 ka BP. The oldest 14C age equivalents were measured on natural diamonds which exhibited the highest current yields. http://www.sciencedirect.com/...rticle/pii/S0168583X07002443
Those are not ages. Those are, as explicitly stated, age equivalents. From samples measured by other valid methods as over 100 Ma. For the specific purpose of monitoring measurement background.
Current instrumentation is incapable of measuring 14C in samples that are really that old (much less 100+Ma), and there's pretty good reason to believe that the range of valid ages will be extended to there or far beyond.
I did not provide a reference because I was referencing information provided by another poster. It seems likely that he is correct about the identification of instrument error. Baumgardner's rebuttal is just speculation.
One complaint I have about your participation here is that you simply fall silent about issues too difficult for you to address. In this case, the bulk of my post was regarding sources of neutrons for producing C-14 from the N-14 resident in a carbon source. We already know that such sources include diamonds.
Until you've addressed that, you have nothing to crow about. It's relatively easy to produce non-age related C-14 in a diamond.
quote:Diamonds supposedly 1–3 billion years old similarly yielded carbon-14 ages of only 55,000 years.
quote:The conclusion affirms C-14 in unusual high amounts in diamond samples.
Given that the limits for measuring ages is somewhere around 55000 years, the diamonds apparently contain only small trace amounts of C-14.
And perhaps Baumgardner's explanation is BS...
quote:Precisely how the silver powder might be producing the observed trend is not clear. Indeed, the authors acknowledge their inability to provide a confident explanation.
Edited by NoNukes, : No reason given.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
I have never met a man so ignorant that I couldn't learn something from him. Galileo Galilei
If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass
Now there's a knee-slapper! Both the presence and absence of silver powder cause the effeect, therefor the effect is caused by silver powder!
In context, I don't see the inconsistency in this claim. Baumgardner is saying that there was no ion-current variation when there was no silver powder present.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
I have never met a man so ignorant that I couldn't learn something from him. Galileo Galilei
If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass
Let's compare this with Baumgardner's results from Carbon-14 Evidence for a Recent Global Flood and a Young Earth (2005), table 4 (with pMC converted to fraction MC for direct comparison with Taylor & Southon; note that these are before "subtracting background" and T&S did not subtract background so they are directly comparable):
Sample ID
Geological Setting
Country
14C/C (fraction MC)
Kimberley-1
kimberlite pipe (Kimberley)
South Africa
0.0010±0.0003
Orapa-A
kimberlite pipe (Orapa mine)
Botswana
0.0014±0.0003
Orapa-F
kimberlite pipe (Orapa mine)
Botswana
0.0011±0.0003
Letlhakane-1
kimberlite pipe (Letlhakane mine)
Botswana
0.0012±0.0003
Letlhakane-3
kimberlite pipe (Letlhakane mine)
Botswana
0.0015±0.0002
Kankan
alluvial deposit
Guinea
0.0011±0.0003
Baumgardner's table 5 is similar:
Sample ID
Geological Setting
Country
14C/C (fraction MC)
NMBclr1
alluvial deposit
Namibia
0.0039±0.0002
NMBclr2
alluvial deposit
Namibia
0.0025±0.0002
NMBclr3
alluvial deposit
Namibia
0.0021±0.0003
NMByel1
alluvial deposit
Namibia
0.0017±0.0002
NMByel2
alluvial deposit
Namibia
0.0012±0.0002
NMBbrn2
alluvial deposit
Namibia
0.0015±0.0002
Note that T&S's results are all at least an order of magnitude less than Baumgardner's. This is another direct proof that Baumgardner's samples were contaminated. Wonder why Baumgardner didn't mention that?
Baumgardner's table 6 (same as 4 and 5 but with "lab's standard background" {which Bertsche demonstrated is seldom used} does contain some results comparable to T&S (from which no background was subtracted), but nowhere does Baumgardner translate these results into an age. Were he to do so maybe someone would notice that the "ages" are mostly well beyond the capability of the method today and are obviously not related to the age of the sample.
quote:What about the RATE diamond measurements? Bertsche alludes to the fact that the RATE team also tested diamond by placing diamonds directly into the AMS sample holder. Our tests were done in 2006 after the RATE book was published in 2005. We obtained results quite similar to those reported by Taylor and Southon in 2007. Our ten diamond samples displayed 14C values between 0.008 and 0.022 pMC, with a mean value of 0.014 pMC. Certainly these 14C levels are much smaller than what we obtained for our coal samples; so, caution is obviously advisable in their interpretation. Nevertheless, unless one has a philosophical bias against such a possibility, the most plausible explanation, astonishing as it may be to some, is that natural diamond contains measurable and reproducible levels of intrinsic 14C.
So they obtained results from 0.00008 to 0.00022 fraction MC, which we can see from the standard calculation { T = -8033*ln(fraction MC) } is from 76 kYa to 68 kYa, well beyond the accepted capabilities of modern instrumentation of 55 kYa to 60 kYa.
Baumgardner claims, at your reference:
quote:It is important to emphasize that placing the diamonds directly in holes bored in the instrument’s cathode sample holder eliminates all of the potential sources of 14C contamination listed in Table 1 of Taylor and Southon’s paper except for items (1), 14C intrinsic to the sample itself, and (7) instrument background.
Nope. It does not eliminate 4 and 6 (where's 5?):
quote:Table 1 summarizes seven major potential sources of pseudo-14C signal in AMS-based 14C measurements... ... (4) Transfer background. 14C introduced during graphite transfer to sample holder. (4.1) Target/cathode contamination: 14C introduced from sample holder. (4.2) Manipulation contamination: 14C introduced during physical transfer/packing of graphite into sample holder.
(6) Storage background: 14C introduced at any point in the sample processing sequence from any containment vessel. (6.1) Particulate contamination: 14C physically introduced from carbon-containing particulates derived from storage containers. (6.2) Atmospheric contamination: 14C introduced fromCO2 in air or from out gassing from storage container
Note also that the contamination sources listed in Table 1 are not all of the possibilities.
Baumgardner's conclusion that intrinsic carbon is the only possibility is wrong.
At your reference he also writes:
quote:Regardless of the actual cause, the glaring fact remains that Taylor and Southon detected levels of C-14 in the diamonds they analyzed that were all well above the intrinsic sensitivity of their AMS hardware.
Baumgardner is correct in that the detected levels are above the intrinsic sensitivity of the AMS. However, he has utterly failed to demonstrate that the signal must be intrinsic carbon, and there are still plenty of reasons to doubt that conclusion. His RATE measurements are obviously from some contamination, especially by comparison to his own later measurements, and his arguments that the detected levels indicate sample age are hollow.
Curiously the upper limit of 14C age measurements is ~55,000 for the best modern equipment and method, and results below that measurement threshold are normally reported as >55,000 years ...
Reporting this a "carbon-14 ages of only 55,000 years." is a falsehood, and a common creationist ploy. Just as this claim is a falsehood:
quote:Even if every atom in the whole earth were carbon-14, they would decay so quickly that no carbon-14 would be left on earth after only 1 million years. ...
And the fossil ammonite ... discovered near Redding, California, accompanied by fossilized wood ... is another hoot. Perhaps you should not trust this site for factual information ...
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