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Author Topic:   Radiometric Dating and the Geologic Column: A Critique
PaulK
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Posts: 17178
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Member Rating: 2.6


Message 2 of 113 (166175)
12-08-2004 8:22 AM
Reply to: Message 1 by Anti-Climacus
12-08-2004 7:41 AM


According to the YEC paradigm ALL the dates - even those classified "too low" are orders of magnitude too high.

Therefore any sources of error that reduce the reported age, as well as errors that rely on the existence of older material to raise the age have no place in the YEC paradigm unless and until a reasoanble explanation for the actual results is found.

In fact without any attempt to explain the results the YEC paradigm can offer no predictions about the nature of the expected errors.

There is a further logical error in that an analysis that is restricted to discordant results cannot confirm point a) because it provides absolutely no information on the frequency of such results.

So thus the predictions have not been shown to follow from the YEC paradigm and no attempt has been made to support point a) despite the fact that that was the major purpose of the post. These are serious errors.


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PaulK
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Posts: 17178
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Member Rating: 2.6


Message 6 of 113 (166221)
12-08-2004 11:57 AM
Reply to: Message 5 by Anti-Climacus
12-08-2004 11:20 AM


I think that you need to take a step back and consider that you haven't proven the imprecision of radiometric dating at all.

Indeed how can we tell that the imprecision found in discordant dates is typical ? Surely if we expect erroneous results to display greater imprecision that applies regardless of which paradigm is true, since both reject the dates in "Woodmorappe's" survey.

To establish that radiometric dating is imprecise you need to take into account both the proportion of discordant results and the nature of the errors. For instance if a result is discordant because it used low-quality material, it cannot be relied on to indicate that radiometric dating is inaccurate when better quality material is available.

As to producing a proper survey any method of obtaining a representative sample should do. It is far from clear that the majority of discordant dates go unpublished - and if they do it will likely be because they are the result of uninteresting errors. If the errors indicate a genuine problem then they will usually be published for that reason.

Moreover creationist orgnaisations seem to have no problem obtaining funds. Answers in Genesis have spent millions on their "Creation Musuem". A simple survey should not require expenditure on anywhere near that scale.

But without real data we should consider that radiometric dates are not produced simply to deny YEC claims. Geologists have an obvious interest in making sure that their methods are accurate and so the presumption must be that discordant dates are relatively uncommon and can usually be adequately explained. Any other assumption has to explain why a profession would continue to use a method that plainly did not work. Indeed it is hard to see that a method that routinely failed could ever become established.

Also there are other dating methods which contradict YEC and have good agreement with radiometric dates. For instance this article deals with sedimentary cycles:
http://www.agu.org/sci_soc/eos96336.html


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PaulK
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Posts: 17178
Joined: 01-10-2003
Member Rating: 2.6


Message 14 of 113 (166239)
12-08-2004 12:33 PM


Review of Woodmorappe
This review appears to refer to the same data. Although the paper was originally published elsewhere it is indicated that it was reprinted in Studies in Flood Geology

Also linked is a reply by Woodmorappe (which takes a very nasty tone) and a response to that reply.

http://www.talkorigins.org/faqs/woodmorappe-geochronology.html

[Added in Edit]
Example 6 gives some indication of the reliability of radiometric dating.
An early (1961) paper on K-Ar dating of glauconite (a difficult mineral to date) reported 5 discordant results Woodmorappe uses. And 40 dates that were within 10% of the expected value. Assuming that there are no other discrepent results this indicates that nearly 90% of the results were within 10% of the expected value - given a less than ideal choice of mineral and in an early paper before there had been much study of the use of this particualr mineral in radiometric dating.
Since the purpose of the paper is to discuss the reliability of dating glauconite there is no reason to suspect that erroneous results have been suppressed, and given that we should expect the results to be poor they are quite good enough to call the YEC claim into question.

This message has been edited by PaulK, 12-08-2004 12:47 PM


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PaulK
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Posts: 17178
Joined: 01-10-2003
Member Rating: 2.6


Message 26 of 113 (166434)
12-09-2004 2:40 AM
Reply to: Message 22 by Anti-Climacus
12-08-2004 11:53 PM


At this stage I must point out that it is not the case that you have established that there are many unpublished discrepant dates. However this assertion appears to be the only support for your assertion. if it is false your claim that discrepant results are frequent is also false.

It is particualrly true in the case of the 1961 Evernden paper. As I pointed out the purpose of the paper was to assess the reliability of dating using glauconite - NOT to provide dates. Therefore unless you wish to call Evernden's integrity into question we DO have valid grounds for assumning that there are no more discrepant dates.
Indeed even given the assumption and my relaince on a secondary source, this example is still the only data that speaks to the FREQUENCY of errors.

Let me also add that you have NOT made a good case for relying on Woodmorappe's data. As I have pointed out by only considering erroneous dates Woodmorappes selected data cannot be validly used for analysing the frequency of errors. Even if it were true that it is not possible to collect a valid data set (and we have seen no reason to beleive that this is so) there are still no valid grounds for using Woodmorappe's data for this purpose.

You would do better to do a better analysis of the imprecision claim taking into account known causes of error for the actual data and also explaining why YEC would predict greater imprecision than conventional geological views in these cases. At least that would represent a valid attempt to support your point b.

You might like to consider why, in your 5 posts to this thread, you have still to even lay the ground work for the two points your original post argued for.


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Replies to this message:
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PaulK
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Posts: 17178
Joined: 01-10-2003
Member Rating: 2.6


Message 27 of 113 (166478)
12-09-2004 7:03 AM
Reply to: Message 1 by Anti-Climacus
12-08-2004 7:41 AM


Predictions of YEC
I'm going to have a go at actually deriving predictions from the basic YEC paradigm - and explaining the reasoning involved
(We should have seen something of the sort in the original post - especially as it is clear that "prediction" a fails to state the expected nature of the discordance - a point I address below - while there is no hint of an explanation for "prediction" b at all)

Since the basic YEC paradigm in no way invalidates the theoretical basis for radiometric dating that will be assumed to be correct for the purposes of this post.

1) Under the YEC paradigm we have two likely sources of igneous rock. Either they were directly created or formed much as conventional geology states after the Creation.

2) Created rock could either include the radioactive isotopes needed for radiometric dating or exclude them altogether. In the latter case the age should appear to be either "infinite" (out of range) or the material should simply be undatable. In the former case the most likely result is that the age would indicate the age since creation. These considerations are independent for each isotope.

[Further explanation - while in principle a rock could be created with a false "appearance of age" there is no hint of a sensible motive for doing so, and God would certainly understand that doing so would deceive future scholars].

3) Rock which formed since Creation should date "correctly" within the limits of radiometric techniques (i.e. it should typically indicate an age of < 10,000 years)

Thus the prediction of YEC are that radiometric dating of rocks should
consistently produce ages at either the extreme upper or the extreme lower end of the scales. While there would be exceptions there is no reason to expect them to dominate and the most reliable dates should virtually always be at the extreme limits.

This is clearly not what is found. The vast majority of dates - including "discordant" dates do not fall at the extreme ends of the scale. The base YEC paradigm does not adequately account for the actual results.

The next stage, therefore, must be to produce a theory to explain the results and produce further predictions from that.


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PaulK
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Posts: 17178
Joined: 01-10-2003
Member Rating: 2.6


Message 75 of 113 (167135)
12-11-2004 5:34 AM
Reply to: Message 60 by Anti-Climacus
12-10-2004 2:36 PM


Re: An Example
It seems that your primary point is that you reject the explanations offered by geologists for "discordant" dates. However I do beleive that you need to provide strong evidence that the explanations offered are incorrect or automatically available in all cases.

Unfortunately I do not see how this could possibly back up your original argument at all, even if it were to be demonstrated that your opinion was correct in this matter. It supports neither of the claims that your original post was meant to do. In my view it would have been far better if you had offered a clear explanation of how your alleged "predictions" are derived from the creationist paradigm and then provided evidence for them.

While others have raised reasonable points I would like to ask why you insist that the two meteorites must be samples, ultimmately derived from the same source. In addition I would like you to explain why you think that this argument would be easily available to geologists dealing with terrestrial sources and especially what evidence you have that the trace element differences used to support the idea are common enough that such evidence would usually be available.

In addition I would like to know why you consider the reference to the potential problems caused by shock melts an example of "preparing excuses in advance". After all even if excuses were prepared in advance there would be no need to report them in the paper The fact that they were mentioned is surely better interpreted as indicating that the authors thought that there was a strong possibility that they would not obtain a valid isochron. If geologists routinely make excuses there should be no surprise that excuses prepared in advance were not needed and certainly no need to express surprise at such an event. This part then is surely evidence against your assertions, not evidence for them.


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PaulK
Member
Posts: 17178
Joined: 01-10-2003
Member Rating: 2.6


Message 89 of 113 (168259)
12-14-2004 7:15 PM
Reply to: Message 83 by Anti-Climacus
12-14-2004 6:46 PM


The number of published discordant dates has little bearing on the number that are unpublished. To establish a claim you must provided sufficient evidence that it would be unreasonable to refuse to accept it. This you have not done.

I also must point out that I suggested only that all interestign discorant dates - which should include all those that could possibly help your case should be published. To argue that they must be published is a waste of time since you are claiming that results that would be classified as interesting should be published.

I also point otu that you claim that radiometric dating is produced to be in accorance with established dates misses the point. If early attempts at radiometric datign had produced obviosuly bad results then geochronologists might rightly have rejected radimetric dating as a failure - instead the results produced were good enough for the method to be accepted. And for further tests to be carried out which also indicated that the methods were reliable.

As to your final paragraph I only note that your "quantitative analysis" was only a count of the number of discordant dates "cherry pcicked" by Woodmorappe without any attempt to consider the frequency. As you have already conceded it could not support your claim. So no, this cannot count to supprot your claim that discordant dates are frequent.

I woul add that there are serious questions over whether the methods used are invalid according to your example - and even if you were correct it would not support either of the two points.

And appealing to quotes which were only ever present in the topiv proposal is a poor way of arguing. Especially as given the all-too-common misuse of quotes in creationist sources every single one of them would probably have to be examined in context before it could be trusted.

And still you have not addressed your claim that your point b) was a prediction of creationism.


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