Talk:Radiocarbon dating/Archive 1

message: Please:
*Propose in this page the examples you want to be considered.
*Include possible rebuttals and/or explanations already.published for each case in scientific publications (i.e., not in Newsweek).
*Do not include moon rocks and other samples not datable using radiocarbon.
Jclerman 06:09, 7 February 2006 (UTC)
replies: text: The stuff about molluscs and moonrocks recently removed from this article has just been given its own article, Controversy on Radiometric dating, again with none of the counter-evidence. It is therefore completely POV. I remember reading that the snail shells were found to come from an ecosystem fed from ancient aquifer-water, but I don't know the source, and I'm not knowledgeable enough to un-POV the new article. Just letting people here know. --Squiddy | (squirt ink?) 14:10, 7 February 2006 (UTC)
replies: text: I've seen the talkorigins answer on that very subject, it actually seems very plausible, but that aquifier water isn't the only thing those snails could of gotten C14 from, unless that water was like diluting most of the water shed and everything around it or something, which I don't think the talkorigins page mentioned. Personally, i'd like to see some of the examples on some of the more famous fossiles of Neanderthals since those are often the most famous things to have controversy over, the talkorigins archive had a very....interesting answer to conflicts on one of those I think, in which it claims that since bones are porous, of course the C14 dates would be all messed up as it would leech into it continually. Which of course begs the question how can any C14 dates of any bones be reliable, I understand how you can use dating methods on the land around it, but then all those other methods have to of been stable for thousands of years which is often very unlikely....but that's just my opinion, in the end, some more things on Neanderthal and other supposed human ancestor dating would be nice. Homestarmy 14:32, 7 February 2006 (UTC)
replies: text:  Risking to be rude, let me ask you whether you have read my response to you in this same page, above, here repeated: All your questions, critiques, and objections have been answered and discussed at length in the references given in the article. The detailed explanations given there are much more complete and thorough than we could do in this column. Also, if there is a radiocarbon dating lab in your locality, you probably could join an organized group visit and get a direct view and understanding of the method. In particular they could "walk you" through all the chemical and physical aspects of sample decontamination. analysis. computation, etc using data from real samples so you could compute yourself their ages and so get an "insider's view". Jclerman 01:22, 29 January 2006 (UTC)
replies: text: Wha? No, I was earnestly suggesting this article contain some more things about it, you asked for ideas, I was giving one, and giving some background information on my opinion, but simply ended by re-iterating that I thought it would be a good thing to put into this article, as those kinds of examples are popular topics. You told me to go get some real reaserch on C14, so I went to talkorigins and looked stuff up, I don't know any carbon 14 labs near my area and I don't see why real information on C14 dating must only be in carbon 14 labs. Homestarmy 16:06, 7 February 2006 (UTC)
replies: text: I do hope useful ideas and text are added. My suggestion to visit a lab is because I don't know what's your background and experience in the sciences and seeing  the procedures and samples is equivalent to hundreds of pages that don't belong here. If you can get hold of a chemistry instructor of a high school or college: ask her/him to show you how to extract the mineral part from bones and shells, until the collagen matrix remains. Then the reply to your questions about bones and shells dating will click. Jclerman 20:17, 7 February 2006 (UTC)

text: Well we have a great chemistry teacher at a great private school but the problem is we don't have a great budget for a great chemistry lab, I think we might of blown most of the funds on silver(II) nitrate anyway :/. But are you saying talkorigins isn't the famed repository of evolutionary knowladge that people sure seem to make it out to be? I mean it seems like a very straightforward site with increadible detail, and the answers seemed very straightforward and earnest and it seems like it was worked on for a very long time, though they did give answers which seemed deceptively simple and short along with deceptively wrong to me at least.... Homestarmy 02:12, 8 February 2006 (UTC)

text: This topic is now being continued in Controversy on Radiometric dating and its corresponding discussion page.Jclerman 15:41, 7 February 2006 (UTC)
replies: text: That page dose not exist now and I see no reason to create it.  The discussion is doing just fine here. Lotu 23:35, 22 March 2006 (UTC)
thread_title:  dating conflicts 

message: The BBC reported that the giant tortoise that recently died in India (Adwaitya) was going to be carbon-dated in order to determine its precise age. (This was reported by BBC-TV; the claim is not repeated in the on-line version of the BBC's report that is linked to from the Adwaitya article above). This sounds strange to me: I thought that what this method dates is the moment of death of a creature, not its moment of birth. The article does not seem to address this question. JanCeuleers 09:56, 25 March 2006 (UTC)
replies: text: The BBC Online says, indeed, that: <<The shell of Adwaita, an Aldabra tortoise, will now be carbon-dated.>> It means the oldest parts of the shell Jclerman 10:20, 25 March 2006 (UTC)
thread_title:  What is being dated? 

message: Hello Jclerman. I'm glad to see there is a watchdog on the article. I note your previous participation in that capacity. But, let me open by saying that I think the article needs more than just a watchdog. For the moment I'm interested mainly in calibration. The article doesn't really tell you what is going on in calibration. It has no mention of bristlecone pine or Irish oak, does not actually tell you in plain English what a calibration curve is or mention any international efforts to agree on a curve. It does not tell you what the formats of a calibrated date mean. A few vague generalities about calibration are all you get. Now, you can find SOME tutorials and expansions in the external links. I just thought this section ought to have more explanation and some pointers. I invite you or anyone to clean up the material below or provide a different write-up. If you do that, I will follow up on what YOU say (or anyone says). If not, why don't you begin by stating your philosophy if different? If we are going to clean up what I wrote below, then please state what internal and external inconsistencies you find, so we can fix it. Fair enough?Dave 12:18, 26 March 2006 (UTC)
thread_title: Opening of discussion

message: "Originally a Carbon-14 half-life of 5568±30 years was used, which is now known as the Libby half-life. Later a more accurate figure of 5730±40 years was determined, which is known as the Cambridge half-life."
If these are measurements then we can't say one is more accurate than the other without presuming some value.   You can't presume values for measurements.
Also, if this statement is referring to the error bars then a number with an error bar of ±40 is NOT more accurate than a number with a smaller error bar however it is less precise, that is all.  
According to the above statement the Cambridge half-life is simply less precise.  The above statement should be fixed.
Unsigned, by 68.70.247.219 00:54, April 15, 2006 
:A better instrument or method gives a more accurate result.
:A measurement can be more accurate and less precise.
:The quoted statement is correct. It might be incomplete vis-a-vis the precision of 40yr vs 30yr, which is, however, not relevant vs 5700yr.
:Jclerman 09:34, 15 April 2006 (UTC)
thread_title:  Cambridge half-life 

message: .....
Daphne A 05:57, 13 June 2006 (UTC)
thread_title:  Discourtesy by Jclerman 

message: Thanks for the correction. I expanded the acronym to avoid further confusion between oceanic agencies. Jclerman 11:07, 13 June 2006 (UTC)
thread_title: NOSAM thanks

message: "I will now point out the largest flaw of carbon dating, it assumes the rate of decrease in carbon on earth has ALWAYS been constant, which is absolute bogus. Carbon dating can only be trusted for smaller dates, such as a few thousand years, because it is mroe logical to assume that less "stuff" has hapenned in the last 2 thousand years or so."
Is he an idiot?--Greasysteve13 15:03, 23 June 2006 (UTC)
replies: text: I believe the question you intended to ask is "Is he correct?" Whether or not your friend is an idiot is of no interest to this encyclopedia. First, ask yourself: why would it be logical to assume that "less has happened" in the last 2 000 years and what would this have to do with radiocarbon dating? Then, read the section "calibration" of this article and ask yourself: do scientists assume a constant level of C14 for absolute (non-approximate) dating? Hope that helps. jdbartlett 16:46, 23 June 2006 (UTC)
replies: text: Thankyou--Greasysteve13 04:13, 24 June 2006 (UTC)
thread_title:  Some idiot told me: 

message: * Radiocarbon dating analyses are destructive. This means that the wood of treering samples is combusted to produce carbon compounds (carbon dioxide, benzene, etc) whose [specific raw (uncorrected, unnormalized) radio]activity can be detected by counting its disintegrations per minute.
* To attain the appropriate precision and accuracy, the determination of such raw   activity requires grams of wood and weeks of counting its radioactive disintegrations.
* The computation of the net specific activity of each sample requires extra weeks analyzing background ("dead" radiocarbon) and modern ("AD1950") standard samples, then to be normalized to a standard C13 value.
* The raw radiocarbon ages are evaluated from the standardized specific net activities described above.
* The series of treerings to be dendrochronologically & radiocarbon dated to be used  to calibrate the radiocarbon dating scale were the result of decades of explorations begun in the early 1960s. Remote sites were explored at diverse latitudes and elevations, searching for unique rare, living and dead millennary trees to obtain suitable samples. They were mostly from protected species. 
* All the determinations of the radiocarbon activities described above have been cross-correlated and preserved as calibration curves (or tables). By definition a calibration curve has quantities of the same kind on both axis, namely calibrated dates (given as Calendar Years) on the horizontal axis and raw ages (given as Before Present years) on the vertical axis. See Example 1.
* Should a conversion curve be preferred, rather than a calibration curve, the ages on the vertical axis can be converted to the original radiocarbon activities by a simple mathematical operation.
* Any radiocarbon activity from a sample to be dated might match the radiocarbon activities of more than a single tree ring. In Example 1, the sample whose activity dated as 900BP old matches 5 different calendar dates which were obtained from 5 different dendrochronologically dated treerings.
* In practice, things are complicated by the statistical uncertainties (a) of the curve itself, which is really a band, (b) the uncertainty distribution of the sample's activity, and (c) the non-monotonic character of the calibration band. Graphical examples covering the statistical uncertainties and their propagation are given here  and here .
--Jclerman 01:39, 11 July 2006 (UTC)
thread_title:  About calibration 

message: This straw poll is being conducted to determine which of the following points of view are favored by users so as to reach a neutral point of view. 
#In a sealed container where Carbon-14 is not replenished "Carbon-14 is never completely gone. It decays exponentially ad infinitum." 
#All Carbon-14 in a sealed container without benifit of replenishment will eventually decay into Nitrogen-14 as the result of Beta decay.
Please sign your name using four tildes (~~~~) under the position you support, preferably adding a brief comment. Since these are opposing points of view please do not sign your name to more than one. 
=== Those who favor the "never gone" point of view (POV number one) ===
=== Those who favor the "eventually gone" point of view (POV number two) ===
#I favor the expression of the second point of view as being neutral for the following reason:
#*Since atoms are indivisible then the number of parent isotopes atoms remaining when the variable P in the age equation  t = \frac{1}{\lambda} {\times} {\ln \left(1+\frac{D}{P}\right)}  is less than one will be zero.  ...IMHO (Talk) 22:47, 5 July 2006 (UTC)
replies: text: *This straw poll has nothing to do with deciding an issue in science. This straw poll is for the purpose of determining how best to synchronize the results of a model of the age equation with scientific reality by those who are apparently old school and learned the age equation prior to the development of personal computers which have allowed students and laymen to do extensive modeling and analysis that has taken them well beyond old school.  ...IMHO (Talk) 14:32, 8 July 2006 (UTC)
replies: text: May I suggest closing and archiving this section?--Jclerman 17:55, 7 July 2006 (UTC)

text: *This straw poll is for the purpose of providing a summary statement for the benefit of readers who may be confused when modeling the age equation and not the place for you to reiterate your inability to comprehend the problem from a lay or student point of view. Hiding information from students will not solve the problem but only make them question why the problem has not been addressed in the past only to learn that it was hidden away as if that would make it forever go away. Please give others who are confronted by this question the right and the opportunity to review previous coverage. Thanks.  ...IMHO (Talk) 01:00, 8 July 2006 (UTC)
thread_title:  Straw poll 

message: #I favor the expression of the second point of view as being neutral for the following reason:
#*Since atoms are indivisible then the number of parent isotopes atoms remaining when the variable P in the age equation  t = \frac{1}{\lambda} {\times} {\ln \left(1+\frac{D}{P}\right)}  is less than one will be zero.  ...IMHO (Talk) 22:47, 5 July 2006 (UTC)
thread_title:  Those who favor the "eventually gone" point of view (POV number two) 

message: #Irrelevant due to being based on a complete misunderstanding and attempted mis-representation of the issue by User:Pce3@ij.net. - Vsmith 00:39, 6 July 2006 (UTC)
replies: text: *This straw poll has nothing to do with deciding an issue in science. This straw poll is for the purpose of determining how best to synchronize the results of a model of the age equation with scientific reality by those who are apparently old school and learned the age equation prior to the development of personal computers which have allowed students and laymen to do extensive modeling and analysis that has taken them well beyond old school.  ...IMHO (Talk) 14:32, 8 July 2006 (UTC)
thread_title:  Those who recognize the irrelevancy of this ''straw poll'' 

message: #Since the development of personal computers and sophisticated software packages such as Excel spreadsheet the ability of the student or laymen to model equations has become commonplace and routine. Therefore it has become necessary to clarify the results of such modeling when applied to the age equations…   ...IMHO (Talk) 10:56, 8 July 2006 (UTC)
replies: text: May I suggest closing and archiving this section?--Jclerman 17:55, 7 July 2006 (UTC)
replies: text: *This straw poll is for the purpose of providing a summary statement for the benefit of readers who may be confused when modeling the age equation and not the place for you to reiterate your inability to comprehend the problem from a lay or student point of view. Hiding information from students will not solve the problem but only make them question why the problem has not been addressed in the past only to learn that it was hidden away as if that would make it forever go away. Please give others who are confronted by this question the right and the opportunity to review previous coverage. Thanks.  ...IMHO (Talk) 01:00, 8 July 2006 (UTC)
thread_title:  Summary statement 

message: Removed the following:
:Not everyone accepts the idea that the half-lives of radioactive isotopes are constant. Many Young Earth Websites claim that the half-life of carbon-14 can be changed by the presence of magnetic fields and may be variable over time. Since the discovery of radioactivity was relatively recent compared to the half-lives of radioactive isotopes it may be too soon to know one way or another. Although most physicists scoff at the idea that magnetism could affect nuclear processes, there are theories that postulate interactions between the elemental forces. One of the most popular theories is called "Heim-Dröscher space" in which a German physicist named Burkhard Heim attempted to reconcile Einstein's General Theory of Relativity with Quantum Physics. Although the theory remains unproven, there is evidence that his theory is correct because it can be used to calculate the exact masses of fundamental particles, which calculations have been substantiated by measurements. Unfortunately the majority of physicists have never heard of Heim's theory, and most of those contacted said that "they couldn't make sense of Dröscher and Häuser's description of the theory behind their proposed experiment."
It was supposedly supported by http://www.newscientist.com/channel/fundamentals/mg18925331.200-take-a-leap-into-hyperspace.html - but I find nothing there to support a controversy here. Vsmith 17:15, 4 January 2007 (UTC)
thread_title:  Controversy - take 2