Talk:Radiocarbon dating

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Suess's curve[edit]

Taylor, in Radiocarbon Dating page 133, refers to the calibration curves of Seuss from 1967 and 1970. Akin, in Science-based Dating in Archaeology, p. 67, says that the first results were in the 1970 paper. Does anyone have access to the 1967 paper to see if there is a calibration curve in it or just the raw data? The 1967 paper is "Bristlecone pine calibration of the radiocarbon time scale rom 4100 BC to 1500 BC", in Radiocarbon Dating and Methods of Low-Level Counting, Vienna, International Atomic Energy Agency, pp. 143–150. The 1970 paper, for comparison, is "Bristlecone-pine calibration of radiocarbon time 55200 BC to present", in Radiocarbon Variations and absolute chronology, edited by I.U. Olsson, Stockholm, Almqvist & Wiksell, pp. 303–312. Thanks for any info on these. Mike Christie (talk - contribs - library) 18:31, 1 January 2014 (UTC)

The 1967 paper seems to be very rare, see here. The 1970 paper is easy to get, but do you have it already? Zerotalk 05:37, 4 January 2014 (UTC)
I don't have it and would be interested in seeing it, if it's easy to get. For one thing, it might provide an internal reference to the 1967 paper that would make it clear whether the graph appeared there first. Mike Christie (talk - contribs - library) 13:24, 4 January 2014 (UTC)
I'll get it soon. Meanwhile, if you ask for the 1967 paper at WP:REX you might get lucky. Btw, you have mail. Zerotalk 19:43, 4 January 2014 (UTC)
I posted the request at WP:REX. Got the email and have replied; thanks! Mike Christie (talk - contribs - library) 20:06, 4 January 2014 (UTC)
The 1970 paper and its calibration curves are in your mailbox. There is mention of a preliminary curve in the 1967 paper. Zerotalk 13:11, 6 January 2014 (UTC)
Received; thanks! The mention of the curves in the 1967 paper is enough for me to get the story right in the article, I think. Mike Christie (talk - contribs - library) 13:40, 6 January 2014 (UTC)

Speleothem Science?[edit]

Does anyone have access to Speleothem Science by Fairchild and Baker? I can see enough of it on Google Books to guess that it would be a good source for how speleothems have been used to extend calibration curves, and for the accuracy of the most recent work which has helped in extending the INTCAL curves. Mike Christie (talk - contribs - library) 00:52, 2 January 2014 (UTC)

Send me mail (link at my home page). Zerotalk 06:11, 4 January 2014 (UTC)
Done; thanks. Mike Christie (talk - contribs - library) 13:20, 4 January 2014 (UTC)

Keenan, Calibration of a radiocarbon date[edit]

I just removed a mention of a statistical critique of current methods of deriving calibrated dates from radiocarbon dates. I contacted the paper's author, Douglas Keenan, who told me there has been no response to the paper in the peer-reviewed literature. The paper looks like it might be a significant contribution but I don't think we can include it here until there is more discussion of the result in reliable sources. Mike Christie (talk - contribs - library) 16:56, 3 January 2014 (UTC)

While I'm not proposing to put it back at the moment, I question your justification. The paper itself is in the peer-reviewed literature and I don't see why waiting for a published response is required. That is not a standard criterion in wikipedia. Zerotalk 01:01, 4 January 2014 (UTC)
Fair enough. Here's what I was thinking. The paper argues that one of the key modern statistical techniques is flawed. The rest of the community appears to be continuing to use that technique without paying any attention to the criticism. Including mention of a single paper that has drawn no response despite a significant claim seems to me to be undue weight; there are thousands of papers each year that relate to radiocarbon, and I think it's best to include only topics that are covered in secondary sources. Once the decision is made to cover the topic then papers can be cited but this is a claim with no coverage at all as far as I can tell. In addition, it's not yet clear how dramatic the effect is -- the real impact seems likely to be on Bayesian analysis but the paper doesn't give examples of Bayesian analysis giving different results. (I plan to ask Keenan about that, and may be able to get a data set from an archaeologist I know to try running it through his analysis, but of course nothing I get back will count as an RS.) Mike Christie (talk - contribs - library) 04:18, 4 January 2014 (UTC)
Ok. Zerotalk 05:21, 4 January 2014 (UTC)

Next steps for the article[edit]

FYI for other editors, here's what I think are the next steps on the article.

  • Finish revising the calibration section -- needs some more details on the process of developing calibration curves, and on how they are used -- simple intercepts, probabilistic methods, and Bayesian analysis for multiple data points.
  • Add a section on archaeological practice -- the secondary sources spend a good deal of time discussing how radiocarbon dating is useless without good field practice to ensure association of the sample with the context to be dated.
  • Add a section giving some examples of how radiocarbon dates have had a dramatic impact on the field, leading to a significant revision in understanding. The Chauvet Cave is one I would like to cover and maybe a couple of others. I would eliminate the list of examples; it's better to have a short list and discuss their impact.
  • Once that's done, do a pass through for consistency and make sure the article is balanced.
  • Review for what can be cut and moved to subarticles -- the article is really too long as it now stands. Create the subarticles and shrink the main article by summarizing them.
  • Copyedit pass.
  • Submit for peer review with a view to GA and FA.

-- Mike Christie (talk - contribs - library) 04:38, 4 January 2014 (UTC)

More notes:
  • This looks like a good source for one of the subarticles; just removed it from the reflist here as it's unused.
  • Would like to expand the short para on Bayesian analysis but haven't yet found a good source.
  • Have moved the calculation details to a subarticle; the section on samples should probably go too.
  • Have removed unused sources; need to go through footnotes next and ensure everything is listed in the refs.
  • Need to go through Currie's article and see what else can be used before taking this to PR.
-- Mike Christie (talk - contribs - library) 11:03, 1 July 2014 (UTC)
  • My thoughts: the article could really use a summary/overview after the lead of what carbon dates in their different forms mean, and the pitfalls of assuming they are all the same. For reasons I entirely understand, at the moment the lead is followed by an exposition from scratch of the physics which will throw most readers. The section headings lower down could also be made more explicit. Johnbod (talk) 14:11, 19 July 2014 (UTC)
    @Johnbod: I think I see your point, but I'm not entirely sure what the contents of an overview section would be. Wouldn't this duplicate the lead to some extent? Or are you saying that the overview section should focus on the method's use in archaeology? If you could give me a couple of bullet points to show what this section would say, that would be helpful. For the section headings, are you suggesting changes such as "Samples" -> "Sample materials and preparation", or "Calibration" to "Converting radiocarbon dates to calendar dates"? Mike Christie (talk - contribs - library) 10:23, 20 July 2014 (UTC)
    No, it would summarize what is below, especially in "Reporting dates", and perhaps add to it. It would explain what the notations around dates encountered in texts actually mean, and the different conventions. The section below should probably explain older conventions, some of which I think are not yet extinct. Also the need for calibration, which I don't think is really clearly explained in that section (that is covered in the lead). Or perhaps just move that section up to below the lead, even though that is well out of logical sequence. A lot more people need to know what datings they encounter actually mean than how to do the lab or calculation work. Overall the article is not very accessible; a lot of the material is very technical and fiddly, but simpler section introductions would help. Johnbod (talk) 13:00, 20 July 2014 (UTC)
    Sorry I'm being slow, but I still don't really understand what you're saying. I took a look at a couple of recent papers; the reporting conventions are quite complicated (see [1] for one I looked at) and I don't think would make much sense without some context given first -- e.g. mentions of CALIB and OxCal, and "calibrated dates". I take your point that a reader is likely to be thrown by the way the article jumps right into the physics, and I'm open to the idea of an explanatory section to start the article, but I'm not sure what it would contain. You suggest that an overview would be a version of the "Reporting dates" section, with some added material, but I think if we talk about what is reported without giving enough context to explain what it means it won't be informative.
    I confess I'm probably too deep in this article to find it easy to think about how a new reader would approach it (though CorinneSD is currently doing a very helpful peer review from a lay point of view). CorinneSD, could you comment here? Given that you didn't have any background knowledge on this topic, do you think an overview section of the sort Johnbod describes would help, and if so, what would go into such a section? Mike Christie (talk - contribs - library) 11:27, 22 July 2014 (UTC)

Parenthesis?[edit]

In several places a left parenthesis appears to have been used in place of the "C" for "carbon". Shouldn't these be changed to "C"? If not, why not? Also, the illustration caption refers to an equation and an inequality, neither of which appear in the illustration.— Preceding unsigned comment added by 74.95.43.249 (talkcontribs)

Can you say where the parentheses appear, and which illustration you're referring to? Mike Christie (talk - contribs - library) 20:58, 8 May 2014 (UTC)
Probably anon is referring to syntax like (14C), but that is correct; the "14" is attached to the "C" not to the "(". Also the first figure does have an equation and an inequality in it. Zerotalk 00:38, 9 May 2014 (UTC)

Recent undo[edit]

I just undid this edit by Buried forest; I think the editor misunderstood that section of CALIB -- they're saying that if the correct half-life value (5,730) is used, it won't give radiocarbon years in a form CALIB can use, because CALIB expects the Libby half-life to be used. Mike Christie (talk - contribs - library) 00:22, 11 July 2014 (UTC)