Radioactive carbon dating

Fossils are not dated using carbon dating. Carbon dating is applicable only to organic remains, which describes very very few fossils, and applicable only to things less than 40,000 to 50,000 years old, which again describes very few fossils. (Older things will still have a little radioactive carbon in them, but the amount does not indicate the age). There's a very good description of the carbon dating method, by a creationist, at How does the radiocarbon dating method work?. Carbon dating is tremendously well validated by comparison with other methods, some involving other radioactive methods and some not involving radioactivity. THer's a nice discussion at Lake Varves.Fossils are dated by using other radioactive methods. The most commonly used methods are U-Pb concordia-discordia methods, followed by Ar-Ar methods, followed by various isochron methods. Usually the fossils themselves cannot be dated, and usually the rocks (typically sedimentary) in which the fossils are encased cannot be dated. Mostly we date igneous or metamorphic rock above and/or below the fossil-bearing formation. Luckily there are lots of such circumstances, enough to put together a pretty comprehensive and cross-checked picture. There's a very good explanation of how radiometric dating methods weork at Radiometric Dating: A Christian Perspective.But you seem to be asking why we think that the decay rate of radioactive material is constant. There are many reasons, both theoretical and experimental. See Re: summing up, & one more question for a brief list of the major lines of evidence. See Claim CF210 for a more detailed discussion with several references.Sorry, Ned, I can't see how to restrict this to just carbon dating and still address his major question.

No, they do not matter. There's been lots of investigation and experiments. As Bill Murray said:

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It just doesn't matter!

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It just doesn't matter!

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It just doesn't matter!

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It just doesn't matter!

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It just doesn't matter!

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This message has been edited by JonF, 05-07-2006 04:51 PM

Yes. They are either ignorant or deliberately misleading, and I think it's unlikely that they are ignorant.14C is produced by high-energy particles ineracting with 14N. Most of it is produced in the upper atmosphere; the high-energy particles are cosmic rays. But it's also known that decay of uranium produces some appropriate particles. So, wherever there is 14N (and we know there's 14N in diamond) and uranium (which might well have been near or in the diamonds; we don't know for sure, but it's quite possible) there is going to be a little 14C.Their claim that diamonds cannot be contaminated with modern carbon (" ...a diamond has remarkably powerful lattice bonds, so there is no way that subsequent biological contamination can be expected to find its way into the interior.") is not supported or reasonable; natural diamonds have flaws and cracks into which groundwater can intrude, no matter how powerful the atomic bonds.The RATE group made no rational scientific estimate of how much 14C should be present in diamonds. I doubt that we have enough data on their history to do so, but I could be wrong. But the RATE guys assumed, without explicitly stating so, that the only source of 14C is the atmosphere; and we know that's not true. So their "study" is worthless, being based on an obviously faulty assumption that they didn't state.

Xenoliths (older inclusions) aren't omnipresent and don't always pose a potential problem, but they are omnipresent in Nguaruhoe lava (as acknowledged by Snelling, the author of the "study"). He specifically asked for a "whole rock" analysis, meaning all the constituents ground up together and then tested, which was guaranteed to produce an age older than the eruption of the lava. From ANDESITE FLOWS AT MT NGAURUHOE, NEW ZEALAND, AND THE IMPLICATIONS FOR POTASSIUM-ARGON "DATING":

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All samples were sent first for sectioning - one thin section from each sample for petrographic analysis. A set of representative pieces from each sample (approximately 100 g) was then despatched to the AMDEL Laboratory in Adelaide, South Australia, for whole-rock major, minor and trace element analyses. A second representative set (50-100 g from each sample) was sent progressively to Geochron Laboratories in Cambridge (Boston), Massachusetts, for whole-rock potassium-argon (K-Ar) dating - first a split from one sample from each flow, then a split from the second sample from each flow after the first set of results was received, and finally, the split from the third sample from the June 30, 1954 flow. ...

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Steiner [90] stressed that xenoliths are a common constituent of the 1954 Ngauruhoe lava, but also noted that Battey [7] reported the 1949 Ngauruhoe lava was rich in xenoliths. All samples in this study contained xenoliths, including those from the 1975 avalanche material.

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Most if not all creationist "studies" of radiometric dating are frauds. This particular one is the most blatant fraud of all of themEdited by JonF, : Fixed tag

It's off topic here, and there's far too much information to cover adequately here, but History of the Collapse of "Flood Geology" and a Young Earth is a good place to start.

They must be really hard to distinguish; they've never been detected, even in experiments measuring half lives. Of course, if there were such a thing, K-Ar dates and Ar-Ar dates would often disagree with other dating methods. Such disagreement is rare and usually explainable by other phenomena, therefore short half life isotopes probably do not exist and, if they do exist, are rare enough to be insignificant.Examples of methods agreeing: Are Radioactive Dating Methods Consistent With Each Other?, Consistent Radiometric dates, Radiometeric Dating Does Work!, Radiometric Ages of Some Early Archean and Related Rocks of the North Atlantic Craton (PDF document).

Actually, U-Th-Pb dating, mostly U-Pb in zircons, is used in over half the geologic dating studies. K-Ar and Ar-Ar combined are around 30%. YECs don't like to address U-Th-Pb dating 'cause it's so robust. K-Ar has the potential of error, especialy when purposefuly misappied by YECs, but it's well-understood and low cost, so it's still useful. OK, I'm thinking. Let's see; lava often contains xenoliths, so it is not impossible to have old rock on and in recent lava; in fact it's fairlyh common. Satisfied? If you are referring to Young-Earth Creationist 'Dating' of a Mt. St. Helens Dacite: The Failure of Austin and Swenson to Recognize Obviously Ancient Minerals, then he did mention xenoliths as one of segveral possibilities for the anomolous dates. Obviously. Do you have any rational reasons for your doubt, or is it just because of your preconceptions?Note that we actually have data that indicates that dating of recent lava flows is often accurate: Ar-Ar Dating Assumes There Is No Excess Argon?. YECs need not one erroneous date, not a hundred erroneous dates, not ten thousand erroneus dates; they need 100%, hundreds of thousands if not millions, of erroneous dates every single one of them. A few anomolies are irrelevant in this context.

Yup. Wher applicable, U-Th-Pb gives even smaller error bars, partly because the decay rates are known more exactly than for any other systems (bombs 'n breeders, you know).Woodmorappe gave a couple of feeble swats at concordia-discordia dating in Mythology of Modern Dating Methods, but they were even feebler than the rest of the book, and that's pretty bad.

I notice you've dropped any pretense of having defndable claims. They're older than the lava flow. And their age is not an assumption. It's a measurement. Are yours secret? Why not? I find it impressive that 70% of recent lavas give accurate K-Ar dates and the remaining 30% have small errors. What's unimpressive? Boy, are you confused. The date is for the lava that covered Pompeii, not the city's structures. Alas, I can't give you or the YECs any credit for attacking any kind of radiometric dating; they're frauds, and you are at least awesomely ignorant of the field and have no basis for any evaluation.

Radioactive carbon dating and its accuracy is not based on any claim on constancy of solar flare activity.

Way off. Rutherford dated the first rock in 1905, and the field was developed continuously from then. Libby invented carbon dating in 1949. Sorry, wrong. In fact, many methods produce the amount of the parent substance that was initially present as a side effect of the method. E.g. isochron methods and the Ar-Ar method.By far the most widely used method, U-Pb, takes advantage of the fact that significant amounts of lead physically and electrically can't get into minerals such as zircons at solidification; the atoms just don't fit. The only significant source of lead in zircons is radioactive decay. This is acknowledged by the few YECs who have some knowledge of the facts: {emphasis in original}We all would appreciate it if you would learn something about the subject before making claims about it. HTH. TIA.

And the initial level of uranium is not part of the equation. I.e., it's irrelevant.Pb-Pb and U-Pb isochrons aren't used all that often. The majority of all dates performed in the last decade or so, and probably before that, are concordia-discordia dates.Address the consilience between different dating methods, proving their reliability, at Age Correlations and An Old Earth (ver 2 no 1).