Uranium Dating

"The process of radiological dating has several intrensic flaws, the most glaring of which is that it assumes set levels of the isotopes measured between samples origionally. For example, in U238 dating, the U238 decays into lead. The only problem with dating samples based on the ratio of the two is that lead occurs natrually, and often in the company of uranium and other heavy metals. The ratio of natural lead to uranium is not constant ether, as lead can occur with little or no radiological involvement.
Basically, there is no way of predicting the actual decay time on the remaining U238, as extra natural lead is everywhere and probably with the uranium wherever it may manifest. This same inaccuracy is inherant in all other methods of radiological dating. Nothing says that the levels of carbon 14 are or were constant at any point in history, or that the levels of solar radiation that cause the isotope in the atmosphere were ever constant."

Thread moved here from the Proposed New Topics forum.

It is good that you acknowledge that this is a quote. But you should always supply your sources as well.

That is just good form. Thanks.

Generally you should contribute in your own words to show that you understand it. Perhaps you can add something to this in your own words.

And yet the different methods of radiometric dating produce dates that are consistent with each other. Since each different radiometric method uses materials that have different chemical and physical properties, we would expect that issues of contamination, leakage, wrong initial amounts, and so forth would cause the different methods to produce different age estimates when applied to the same geologic units. Yet, these different methods will produce the same ages for the same geologic units.

So it seems that the potential problems of extra decay products or contamination or leakage of parent isotope aren't serious issues after all.

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Speaking personally, I find few things more awesome than contemplating this vast and majestic process of evolution, the ebb and flow of successive biotas through geological time. Creationists and others who cannot for ideological or religious reasons accept the fact of evolution miss out a great deal, and are left with a claustrophobic little universe in which nothing happens and nothing changes.
-- M. Alan Kazlev

The process of radiological dating has several intrensic flaws, the most glaring of which is that it assumes set levels of the isotopes measured between samples origionally. For example, in U238 dating, the U238 decays into lead. The only problem with dating samples based on the ratio of the two is that lead occurs natrually, and often in the company of uranium and other heavy metals. The ratio of natural lead to uranium is not constant ether, as lead can occur with little or no radiological involvement. Basically, there is no way of predicting the actual decay time on the remaining U238, as extra natural lead is everywhere and probably with the uranium wherever it may manifest. This same inaccuracy is inherant in all other methods of radiological dating. Nothing says that the levels of carbon 14 are or were constant at any point in history, or that the levels of solar radiation that cause the isotope in the atmosphere were ever constant.

Radiometric dating using uranium/lead involves the analysis of zircon crystals. Zircon crystals readily incorporate uranium into their structure but do not do so with naturally present lead. The lead that is present in the structure of the zircon structure can thereby be assured to be radiogenic (decayed from uranium). Thus this is not as much a major issue that you present here.

Also, several radiological dating method have various different factors than can adversely influence the results. However scientists take this into account and place a error factor into these results. Their are also many work arounds with these as well as comparison analysis made with other dating methods. For example, if dozens of dating methods pointing to the old age of earth i.e. 4.5 billion years and a couple of dating methods have slightly different results (say 4 billion instead of 4.5 billion years for the age of a rock), this does not mean that we should throw out this estimated age and say that the Earth is really 6000 years old because people interpret an ancient manuscript to say so.

Edited by DevilsAdvocate, : No reason given.

Apparently this is a 'claim' from his room mate.

http://www.thenakedscientists.com/forum/index.php?topic=18360.msg206262

Major faux paus on my part, this should never have been promoted.

Participants in this thread should take care to not invest much time until Contingent's familiarity with the topic becomes more clear.

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--	Percy
	EvC Forum Director

Nothing says that the levels of carbon 14 are or were constant at any point in history, or that the levels of solar radiation that cause the isotope in the atmosphere were ever constant."

This is a standard creationist argument which shows a lack of understanding of the radiocarbon method rather than a flaw in the way radiocarbon dates are obtained.

It was understood early (de Vries, 1958) that the levels of C14 in the atmosphere fluctuated. Accordingly, a calibration curve has been developed and refined to account for those variations, which are not very large anyway.

That calibration curve is based on tree rings and other annual data. The method is simple -- count tree rings back to, say, 10,000 years and radiocarbon date that ring. That gives you a date on a sample of a known age. By comparing the date returned against the known date, you can see what correction may be needed.

If I remember correctly, this has been done in one year increments back into the 1600s, and ten year increments back to about 12,600 years ago using the standing dead bristlecone pines from the White Mountains of Southern California. This has resulted in a fine calibration curve.

I believe the curve has been extended past 20,000 using other annular materials from other areas.

But in spite of this, creationists keep spreading the misinformation that the C14 method is erroneous when in fact it is the creationist's information that is erroneous.

And I might add, this is so often the case. Wishful thinking, a distaste for science and scientific research, and an overriding belief in creationism somehow don't lead to the most accurate scientific pronouncements. Coupled with the need to evangelize, this misinformation has been spread all over the web. You seem to have posted this exact misinformation over on the James Randi Educational Foundation website.

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Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

Apparently this is a 'claim' from his room mate. http://www.thenakedscientists.com/forum/index.php?topic=18360.msg206262

Here too:

http://forums.randi.org/showthread.php?t=129136

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Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

Typical scatter shot, hit and run bullshit.

I believe the curve has been extended past 20,000 using other annular materials from other areas.

And to about 45,000 years ago from lake varves in Japan. About ten methods all correlate with each other, too.

The lead that is present in the structure of the zircon structure can thereby be assured to be radiogenic (decayed from uranium).

And the isotope of lead involved also correlates with the uranium (238U produces ONLY 206Pb) while naturally occurring lead does not discriminate between isotopes.

isotope  % naturally occurring
206Pb    24.1% 	206Pb is stable with 124 neutrons
207Pb    22.1% 	207Pb is stable with 125 neutrons
208Pb    52.4% 	208Pb is stable with 126 neutrons

Then there is the issue of Uranium halos ...

Enjoy.

Being a bit pedantic ...

The lead that is present in the structure of the zircon structure can thereby be assured to be radiogenic (decayed from uranium).

True ... to a first approximation. But that's not good enough for today's scientists, for whom sub-1%-accuracy is where it's at. A very small amount of lead does get incorporated in zircons at formation. Correcting the results for that small amount of initial lead is routinely done, usually based on the amount of Pb, which is not radiogenic and therefore is initial (addition of lead after formation is unusual enough to be ignored). There are also methods that don't depend on sup}204Pb.

Of course, the correction is always many orders of magnitude smaller than that needed by creationists to validate their fantasies.

http://www.es.mq.edu.au/GEMOC/comPbcorrect/Intro.htm

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Uranium is not formed in stars through ordinary thermonuclear fusion processes. Instead, it is formed in supernovae - the only places with enough pressure and heat to generate these unstable nuclei.

This is very true, which leads me to ask... are all the girls featured in your website astrophysicists? If so, I would be very interested in asking them to join my own research group.