Isometric dating: Recipe for fudge

[npetreley]

I found an interesting anti-Creation article. Before I get started on the point I want to raise, allow me to (at least attempt to) nip some useless distractions in the bud. First, I have never said what I believe to be the age of the earth, and I'm not going to air my views now, because that isn't the point. Also, there are some valid points raised in this article - I am not trying to discredit the whole thing.

What I do want to point out is that there is something within his defense that confirms exactly what I've been saying all along about isometric dating. You get the results you expect because you toss out the results you don't expect. Once again, that is NOT science.

Here's the article:

Woodmorappe's Shell Game: Refuted with Literature from his Creationist Allies

http://home.austarnet.com.au/stear/woodmorappe_henke.htm

Here's the outrageous portion of his defense:

Austin and Snelling’s (1998) samples were dated with K-Ar by Geochron Laboratories, a radiometric laboratory in Cambridge, Massachusetts, USA. Although Austin and Snelling (1998) informed Geochron personnel that the samples have a general "basaltic" composition and that they should expect "a lot" of argon from the samples, they never gave individuals at Geochron expected ages or locations for the samples. Because Geochron personnel had no way of knowing the origins and ages of the anonymous samples, they could not have known which dates were reasonable and which were not. Furthermore, Austin and Snelling (1998) make no accusations that Geochron personnel wanted age estimates as a way of "cheating" or "culling" any possibly unreasonable results. Even if the dates were in excess of 4.5 billion years or had negative values, Geochron personnel could still view them as part of some sort of special laboratory isotope study. That is, such a study could involve spiking samples with pure isotopes so that they would produce unusual dates as part of some legitimate experiment. So, if Geochron personnel want to keep Austin and Snelling as valued customers, they have no choice but to truthfully report whatever results they get with Austin and Snelling's anonymous samples and not try to make any second-guesses. Therefore, with Austin and Snelling (1998), as well as their other articles that contain original radiometric dates, we are dealing with dates in the hands of analytical chemists and YECs that have no motive and/or ability for identifying and removing any ridiculous results. Indeed, Austin and Snelling (1998) clearly state that they submitted 13 samples for dating and they list all 13 corresponding dates for those samples.

In short, this author is complaining that Austin and Snelling violated the normal procedure: Tell the Geochron Lab the rough dates you expect so that they can treat any dates outside that range as anomalous.

He says this is reasonable, but this is actually tantamount to handing samples to the lab and saying, "These samples should be about 700 million years old." The lab tests one sample. "500 million years old. That's a bad one, toss it out. 1 billion years old. Bad one, toss it out. 710 million years old. Good one. Ok, here are your results. The samples are 710 million years old."

As a side note -- and this is ONLY a side note, not the main point -- I find it humorous that the author considers it a victory that the 13 samples only have varying values between 577 and 984 million years, as if that's a good thing.

Can you imagine imposing that margin of error on dates we assume to be correct? Yeah, well, the dinosaurs went extinct 64 million years ago, give or take 200 million years. Sure, that means the could go extinct sometime in the future.

 

[randman]

"Because Geochron personnel had no way of knowing the origins and ages of the anonymous samples, they could not have known which dates were reasonable and which were not."

Case closed. How can any reasonable person argue with your analysis here?

 

[Morat]

And now the thrilling conclusion:

The 13 K-Ar dates in Austin and Snelling (1998, Table 1) ranged from 577 to 984 million years. Dates on the Cardenas Basalt and associated diabases from the literature are also included in Austin and Snelling's table and range from 791 to 1013 million years. Now according to Woodmorappe Bingo, Austin and Snelling (1998) should have gotten a series of random numbers that could potentially range from negative dates to results that greatly exceed 4500 million years (Woodmorappe, 1999, p. 87). Yet, Austin and Snelling clearly state that their 13 samples only have values between 577 and 984 million years, which are close to the dates for the related samples from the literature. If Woodmorappe's charges that radiometric dates are based on "chance" are correct, where are the dates in excess of 1000 million years and the values below 500 million years in Austin and Snelling (1998)?

With the data from Austin and Snelling (1998), log values of the 500-1000 million year K-Ar dates fall into the positive second standard deviation for Woodmorappe's short-running log normal distribution (381 to 1,020 million years). Only about 13.6% of all values from a normal distribution would be found in the range of 380 to 1,020 million years. Using Woodmorappe's short-running log normal distribution, the chances of obtaining 13 dates in a row within the range of 500-1000 million years are MUCH LESS than 1 in 180,000,000,000.

I'm not suprised to see Randman advocating using dating methods incorrectly on samples (which is, in fact, what Austin has a history of doing), but I'd have hoped Nick had more brains.

 

[DrLao]

I thought that traditional K-Ar dating couldn't be done on basaltic rocks because they always contain some Ar contamination. They don't say what technique they were planning to employ to date this rock, but perhaps some additional information was needed since the chances of contamination were so high?

 

[randman]

"Because Geochron personnel had no way of knowing the origins and ages of the anonymous samples, they could not have known which dates were reasonable and which were not."

 

[Morat]

Randman likes to pretend that radiometric dating is simple and straightforward, and that every method works for every rock.

However, any search of the literature will show you that a lot of radiometric dating is determining what methods are appropriate for a rock, and how to avoid problems like inclusions.

With Austin, it's pretty simple: K/Ar dating doesn't work on young samples with low Argon. Austin claimed his samples were clearly old enough (any geologist uncertain of whether his sample was old enough would use a different radiometric method to date it) and had enough Argon.

Both claims were untrue, which resulted in a bad date for the rock (although, you note, consistantly bad dates. In direct contradiction to Woodmaroppe's claims). In most case, the Geochron lab would have had context and a general expected age (between 100 and 400 million years, or "possible inclusions") to determine whether their method had yielded bad results.

If that had been the case, the lab could have checked it by dating with another method, or dating the inclusions to determine if that was the problem, or a whole host of other methods.

Which is how dating works. If you don't belief the date you get back, you have to track down the error.

In this case, it was testing a young, low-Argon sample via a method that is known to not work for young, low-Argon samples.

Austin's complaint (and randman's) is like griping you burnt out your engine because you ran it on diesel and not unleaded. It's not the engine's fault. It's yours, for being an idiot.

 

[randman]

"Because Geochron personnel had no way of knowing the origins and ages of the anonymous samples, they could not have known which dates were reasonable and which were not."

What can anyone say to that?

Btw, this is getting old. The evolutionists have taken a beating today. I'll check back later to see if something more interesting has come up.

 

[Morat]

Argumentum ad repititum ad nauseam.

Most people grow out of it around the age of 5.

 

[randman]

"Because Geochron personnel had no way of knowing the origins and ages of the anonymous samples, they could not have known which dates were reasonable and which were not."

Maybe rather than address something else, you could explain why evolutionist dating methods first need approximations? Sounds fishy to me.

 

[Morat]

Maybe rather than address something else, you could explain why evolutionist dating methods first need approximations? Sounds fishy to me.

I have, several times. But here it is again.

Some methods only work on certain types of samples, between certain ages. K/Ar dating, one of the cheapest methods, is one such.

Here, from Geochron labs:

The potassium-argon (K-Ar) method of age determination is based on the radioactive decay of naturally occurring 40K to stable 40Ar. 40K has a half-life of approximately 1.3 billion years, enabling a wide range of geologically useful ages to be measured. Ages from less than 1 million years to over 4.5 billion years can be measured by this technique, thus, encompassing virtually the entire geologic time scale.
The analysis of a sample for potassium and radiogenic argon determines the parent-to-daughter ratio. This, plus the well-known decay constants for 40K, allows the calculation of time elapsed since the formation or cooling of the potassium bearing phase.

(It's nice to see they've tightened up the short end. According to another source, with an ideal sample, you can now date rocks as young as 100,000 years with this method. Science marches on).
Or Here

C. Problems and Limitations of the K/Ar dating technique

Because the K/Ar dating technique relies on the determining the absolute abundances of both 40Ar and potassium, there is not a reliable way to determine if the assumptions are valid. Argon loss and excess argon are two common problems that may cause erroneous ages to be determined. Argon loss occurs when radiogenic 40Ar (40Ar*) produced within a rock/mineral escapes sometime after its formation. Alteration and high temperature can damage a rock/mineral lattice sufficiently to allow 40Ar* to be released. This can cause the calculated K/Ar age to be younger than the "true" age of the dated material. Conversely, excess argon (40ArE) can cause the calculated K/Ar age to be older than the "true" age of the dated material. Excess argon is simply 40Ar that is attributed to radiogenic 40Ar and/or atmospheric 40Ar. Excess argon may be derived from the mantle, as bubbles trapped in a melt, in the case of a magma. Or it could be a xenocryst/xenolith trapped in a magma/lava during emplacement.

Austin's sample was below the minimum age and had xenoliths.

Knowledge of either of these problems would have led the Geochron lab to suggest dating the xenoliths (so as to determine if the date was really that of the xenolith, and not the sample) or suggesting another dating method to deal with it's potentially young age.

 

[npetreley]

Originally posted by Morat

Knowledge of either of these problems would have led the Geochron lab to suggest dating the xenoliths (so as to determine if the date was really that of the xenolith, and not the sample) or suggesting another dating method to deal with it's potentially young age.

But there was no potentially young age. That wasn't the point, and that wasn't the result.

Regardless, you can't possibly make a case for this process being scientific. You don't tell the lab what dates are acceptable when you hand them evidence, or what you've done is deliberately filtered the results to match your preconceived conclusions. WHY BOTHER GIVING THEM ANY SAMPLES AT ALL? Just slap a "710 million year old" label on the samples and be done with it.

IMO that's how the whole theory of evolution has been propped up despite the fact that the corpse has been rotting for decades.

 

[randman]

"Some methods only work on certain types of samples, between certain ages. K/Ar dating, one of the cheapest methods, is one such."

That can explain the need to exclude early rocks, maybe, but not the general need for estimations of age. The idea that they throw out some measurements based on predetermined estimations/desires? of rock ages is pretty shocking. While this one example may be covered by what you are stating, it doesn't explain the statement.

"Because Geochron personnel had no way of knowing the origins and ages of the anonymous samples, they could not have known which dates were reasonable and which were not."

 

[npetreley]

Precisely, randman.

"Because Geochron personnel had no way of knowing the origins and ages of the anonymous samples, they could not have known which dates were reasonable and which were not."

That tells you that it is standard practice to tell the lab what kinds of results to expect, regardless of the dating methods being used, so that they know which dates to discard.

As I've said many times, it doesn't matter what the truth is because as long as you throw out the evidence that contradicts your a-priori assumptions, you'll never find it.

 

[Jerry Smith]

Originally posted by npetreley
Precisely, randman.

"Because Geochron personnel had no way of knowing the origins and ages of the anonymous samples, they could not have known which dates were reasonable and which were not."

That tells you that it is standard practice to tell the lab what kinds of results to expect, regardless of the dating methods being used, so that they know which dates to discard.

As I've said many times, it doesn't matter what the truth is because as long as you throw out the evidence that contradicts your a-priori assumptions, you'll never find it.

Occur to anyone here that if you give Geochron a rock with an expected age & they get 20 values that fall outside the range and only one inside of it they might actually tell you that??

No, probably not.

 

[LiveFreeOrDie]

Originally posted by npetreley
He says this is reasonable, but this is actually tantamount to handing samples to the lab and saying, "These samples should be about 700 million years old." The lab tests one sample. "500 million years old. That's a bad one, toss it out. 1 billion years old. Bad one, toss it out. 710 million years old. Good one. Ok, here are your results. The samples are 710 million years old."

Are you claiming that Geochron Labs throws out results that don't match the expected age? Where is your proof? Why would someone spend thousands of dollars to have someone tell them an answer they already know?

Could it be that you don't really know what you're talking about?

 

[Jerry Smith]

Because Geochron personnel had no way of knowing the origins and ages of the anonymous samples, they could not have known which dates were reasonable and which were not. Furthermore, Austin and Snelling (1998) make no accusations that Geochron personnel wanted age estimates as a way of "cheating" or "culling" any possibly unreasonable results. Even if the dates were in excess of 4.5 billion years or had negative values, Geochron personnel could still view them as part of some sort of special laboratory isotope study. That is, such a study could involve spiking samples with pure isotopes so that they would produce unusual dates as part of some legitimate experiment. So, if Geochron personnel want to keep Austin and Snelling as valued customers, they have no choice but to truthfully report whatever results they get with Austin and Snelling's anonymous samples and not try to make any second-guesses.

He thinks his support is found in the first sentence of this quote. He apparently didn't read the rest, even though he included it and more in his original post.

 

[npetreley]

Originally posted by LiveFreeOrDie

Are you claiming that Geochron Labs throws out results that don't match the expected age?

Yes. The whole paragraph makes no sense otherwise. Geochron had no other choice than to truthfully report the results they got. What should shock you is that the writer seems to think this is a bad thing.

 

[Jerry Smith]

What do you reckon would happen if you got just a random rock from a stratum containing dinosaur fossils and sent it off to a lab & told them it to expect it to be 1 by old.

Creationists come up with some awfully clever little schemes to get bad dates from a rock, and then when their schemes are revealed, the whistle-blowers get flak for mentioning over-all methodology flaws, but heck - with this simple little experiment, you could gain valuable insight into the "bias" of the dating methods AND into their overall accuracy.

 

[LiveFreeOrDie]

Originally posted by npetreley


Yes. The whole paragraph makes no sense otherwise. Geochron had no other choice than to truthfully report the results they got. What should shock you is that the writer seems to think this is a bad thing.

How about answering my other two questions then:

1. Where is your proof that Geochron Labs throws out results that don't match the expected age?
2. Why would someone pay thousands of dollars for someone to tell them an answer they already know?

Oh, I forget. Scientists are stupid, liars, or both.

 

[LiveFreeOrDie]

Originally posted by npetreley
In short, this author is complaining that Austin and Snelling violated the normal procedure: Tell the Geochron Lab the rough dates you expect so that they can treat any dates outside that range as anomalous.

You know, I can't believe you completely ignored the sentence following the one you highlighted:

"Furthermore, Austin and Snelling (1998) make no accusations that Geochron personnel wanted age estimates as a way of "cheating" or "culling" any possibly unreasonable results."

Now if Austin and Snelling (the YEC researchers) didn't feel justified in making those accusations, then how on Earth can a completely uninformed observer like npetreley?