Talk:Radiometric dating/Archive 1
This is an archive of past discussions about Radiometric dating. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 | Archive 2 |
Invitation
Work is currently in progress on a page entitled Views of Creationists and mainstream scientists compared. Also currently being worked upon is Wikipedia: NPOV (Comparison of views in science) giving guidelines for this type of page. It is meant to be a set of guidelines for NPOV in this setting. People knowledgable in many areas of science and the philosophy of science are greatly needed here. And all are needed to ensure the guidelines correctly represent NPOV in this setting. :) Barnaby dawson 21:32, 27 Dec 2004 (UTC)
- Does this mean every geology and archaeology article will have to contain creationist explanations as well? adamsan 23:06, 27 Dec 2004 (UTC)
- No of course not. This page is only meant to refer to pages who's principle aim is a comparison of scientific positions (or in the case above positions where there is dispute over the scientific nature of a position). Barnaby dawson 11:47, 28 Dec 2004 (UTC)
- They should contain creationist explanations. Everone on here uses the excuse "pseudoscience" to keep creationism from "leaking" onto the articles. Scorpionman 14:37, 12 April 2006 (UTC)
- This is because creationism is not science, it is a religious belief. Radiometric dating establishes facts through objective, verifiable methods. Slrubenstein | Talk 17:13, 12 April 2006 (UTC)
- Scorpionman is an avowed creationist, so we'll just ignore his blathering because he's pissed that a bunch of scientist-friendly folk over on Age of the Earth aren't letting him and others turn it into a bullet-point bitchfest comparison of science and creation "science". Rolinator 01:43, 13 April 2006 (UTC)
Needed additions
We seem to be missing information on U238/U234 dating--nixie 01:21, 10 Apr 2005 (UTC)
- The use of those two U isotopes alone for dating is quite rare, perhaps best discussed under 238U-234U-230Th dating in which they play an essential part. Actinide 11:40, 20 Jun 2005 (UTC)
- There is a uranium-uranium dating article now. The glaring omission is uranium-lead dating. Actinide 03:17, 11 July 2005 (UTC)
- Radiocarbon dating is mentioned here, but not cosmogenic nuclide dating. Is this simply accidental omission of a relatively obscure technique, or are cosmogenic techniques seen as somehow less "absolute"? The list of techniques in this article seems to emphasize "hard rock" formation-decay type techniques (exceptions are radiocarbon, o. I'll be the first to admit there are non-absolute dating applications of cosmogenic nuclides (erosion rates, non-unique solutions, etc), but they are certainly not the rule. I'll add something on cosmo techniques if no one objects. Also, can we organize the long list of techniques at the beginning of the article? --BlueCanoe 01:41, 23 February 2006 (UTC)
- Strictly speaking, cosmogenic nuclide dating is a calibrated radiometric technique rather than an absolute radiometric technique (the only constants requied for the latter are half-lives). But this article is about "radiometric dating," not "absolute radiometric dating," so of course cosmogenic dating should be mentioned here. And yes, this article needs a lot of work. Actinide 13:15, 23 February 2006 (UTC)
Merge from POV fork
The POV fork Controversy on Radiometric dating is inappropriate, as there is plenty of room here for anything that could be contained there. I propose merging that article back here and deleting/redirecting it. Peyna 15:55, 17 February 2006 (UTC)
- Just a note I've listed that article for AfD. Peyna 02:29, 23 February 2006 (UTC)
New article: religious controversy
- Controversy on Radiometric dating inappropriately handled religious reaction to radiometric dating with a POV slant. However, the existence of a separate article discussing the religious and sociological impact of radiometric dating results (as opposed to the scientific practice of radiometric dating) should be preferred to the alternative of squeezing both topics into one article. This was recently discussed in the Talk page of the radiocarbon dating article: Talk:Radiocarbon_dating#Controversy. I'm currently drafting a new article (not a recreation of the rightly deleted Controversy on... article) to handle this separate non-science topic. However, before I post the new article, I would like to hear from contributors to this article: are you agreement with the outcome of the debate in the radiocarbon dating article's Talk page? Thanks. jdbartlett 16:24, 23 June 2006 (UTC)
Another merge suggestion
The radiogeology article appears to be repetition of material found here. I suggest merging radiogeology into radiometric dating. --BlueCanoe 01:41, 23 February 2006 (UTC)
- I wrote the "radiogeology" article as a broader and more simplified article than this one. I tried to make it as easy as possible to understand and as somewhat of an introduction to the matter. This article is more for those who already understand the topic and need further reading, in my opinion. Radiogeology is a broader topic than radiometric dating, and thus, the radiogeology page serves to direct readers to other pages--one of which may be the article on radiometric dating. --Primetime 02:42, 23 February 2006 (UTC)
- I'd never heard of "radiogeology" before, and a quick Google search returned a miniscule 236 hits indicating usage of this word is essentially nonexistent (c.f. the phrase "Radiometric Dating" which returns 302,000 hits). Also, it turns out a number of those hits, e.g. [1] are almost word-for-word identical to the radiogeology article - presumably this is not how things are supposed to work here? Lastly, I can't see that there is any content currently in radiogeology that should not also be in this article, and if this article is seen to be deficient then it would be better to fix it than to fork it (this goes for the "controversy" fork above too - I think it should be merged in and edited as part of this article because if any evidence of a controversy can be found then it should obviously be presented here). Actinide 06:00, 23 February 2006 (UTC)
- Well, I can see that consensus is against keeping the articles seperate. I'll just merge them. --Primetime 07:19, 23 February 2006 (UTC)
- All done. --Primetime 07:29, 23 February 2006 (UTC)
- Thank you Wikipedia for such a wonderful article. You always know what is going on and share everything you know
Addition
There should be a section on this page entitled "Problems with radiometric dating". Scorpionman 19:18, 24 April 2006 (UTC)
- If you can find a reliable source in a serious, peer reviewed journal that says there are problems, and it isn't a quote mine, you are welcome to discuss putting it in. Otherwise, please stop trolling all the science pages that make you feel uncomfortable and try to actually make some productive edits in article space. Thanks. JoshuaZ 21:26, 24 April 2006 (UTC)
there arent any problems with radiometric dating! i do it every day!
Coarse dating
Please explain granularity of one half-life staement in the section. Vsmith 03:19, 26 June 2006 (UTC)
- Thanks for asking. It meant granularity used as in physics and statistics, similar to resolution in graphics. Anyhow, it was incorrect to apply it to the method described. The expression was a remnant of a previous attempt to describe an intuitive method. I have eliminated the section. Jclerman 05:47, 26 June 2006 (UTC)
- Course dating simply means unrefined dating as when no calibration is applied. Granularity refers to the degree of coarseness as in significant digits of a measurement. In essense refering to a whole half-life versus any decimal fraction thereof. ...IMHO (Talk) 05:22, 26 June 2006 (UTC)
The date equation
The carbon-14 stuff has been replaced by a more general section valid for all parent-daughter decays. Carbon 14: (a) is only one of many isotopes used, and (b) is treated extensively in several other articles. Jclerman 20:34, 27 June 2006 (UTC)
- Would this equation have problems if the daughter is unstable? Dan Watts 20:57, 27 June 2006 (UTC)
replace constant with variable number of half lives
Please, Pce3, don't introduce variable number of half lives where they don't belong to. Jclerman 11:39, 29 June 2006 (UTC)
Equation as published produces incorrect results
I know this formula came from the USGA website but it was published only as a means of showing the relationship of the variables and not for the purpose of calculations even though the variable definitions are included as the disclaimer above the so called age equation states it is the:
"...mathematical expression that relates radioactive decay to geologic time..."
For age computation you need to replace the constant for a single half-life with a variable to represent the number of half-lives.
Thus
becomes
where is the number of half-lives.
Do a few calculations to see.
...IMHO (Talk) 19:58, 29 June 2006 (UTC)
- The burden of proof is on you. Show your calculations. --Jclerman 20:16, 29 June 2006 (UTC)
- Since Wiki math is not functional yet I can't offer equations here that you can plug values into. How about giving me some values for P and D etc. and I will give you comparative examples in return based upon the values you give. Please limit the number of sets to about five. That should be plenty enough proof. ...IMHO (Talk) 21:49, 29 June 2006 (UTC)
- I didn't mean equations. I am expecting you show your calculations, or your work as they called that in high-school. Plug in numbers in the formulas and show your work. Just one or if you want two examples should be enough. No computer needed, not even a calculator. The formula is so simple that can be tested inside our heads. Perhaps the problem is that you chose inappropriate numbers for your tests? Show them, or choose two new sets.--Jclerman 22:46, 29 June 2006 (UTC)
- I'm happy to show you my calculations using my values but in order to eliminate the idea that my values somehow defy the laws of physics and mathematics as an issue right up front I would prefer to use your valuues to start. I'll then do a separate set of calculations with my values if you are not convinced or if I have some issue with your values. ...IMHO (Talk) 02:17, 30 June 2006 (UTC)
OK. Use D = 16, P = 4, 1/λ= 8033 (for C-14 using 5568 yr/HL) plug 'em in and crank out the results. The relationship is a mathematical equation and directly usable as is. What is the solution? And yes, C-14 measurements aren't done that way, but the equation works. Vsmith 03:55, 30 June 2006 (UTC)
- Okay I have done the calculations using these values and have obtained the results. However before showing them to you please allow me to express the following concerns. Since 14C is the parent isotope and 14N is the daughter isotope and their numbers of atoms are represented by P and by D respectively their values would be a bit higher in the real world. Also allow me to point out that their values would be identical since their transformation is based upon Beta decay. 14C is usually shown as having a half-life of 5700 plus of minus 30 years. [Note: In the table below the decay constant λ value of 0.000124 has been obtained as the inverse of the value for half-life you have given above and the alternate value of 5568 yr/HL not used.]
- Even with these values, however, the results of the calculations are the same. I will now proceed to "package" the calculations for display here which may take a little time since the HTML and Wiki markup code has to be manually reconfigured since I do not yet have a macro to do the conversion of the code. Should not be more than an hour. Thanks for your patience and I'll be back with you then. ...IMHO (Talk) 04:28, 30 June 2006 (UTC)
- Okay now just to be sure we are on the same page please verify that I have correctly matched your values with the appropriate designations in the table below:
Number of atoms parent isotope Carbon-14 |
Number of atoms daughter isotope Nitrogen-14 |
Percent parent isotope found in archaeological sample compared with modern sample "p = 1/(2^n)" |
Number of half-lives of parent isotope "half-life = ln(1/p)/ln(2)" |
Half-life value of parent isotope |
Decay constant of parent isotope |
P |
D |
p |
n |
half-life |
λ |
4 |
16 |
1 |
0 |
8033 |
0.000124 |
- A few hints:
- Your physics is incorrect. D and P are not equal. It is the decrease in P that equals the increase in N.
- So then you (or someone else in one of the previous discussions (I'll go back and try and see who it was that rejected this idea) no longer reject the idea of the transition in numbers of atoms from 14C to 14N as the result of Beta decay which I was showing in table provided on the half-life discussion page? If not then their is no need for recalculation. ...IMHO (Talk) 08:21, 30 June 2006 (UTC)
- You do not need n to apply the USGS date equation.
- You do not need p to apply the USGS date equation.
- You might want to use p to verify the results from the USGS date equation with an alternate formula. Then, first check your arithmetic because for the given D and P there is not 1 percent of parent isotope in the sample as you indicate, incorrectly, in your table.
- The table column format is the only problem here. The format is set for decimal rather than percentage display. The 1 actually represents 100% in decimal format. ...IMHO (Talk) 08:21, 30 June 2006 (UTC)
- The about 8000 yrs value is OK, but notice that it is called mean lifetime.
- Now, plug the numbers in the equations and get the answers.
- --Jclerman 07:27, 30 June 2006 (UTC)
- A few hints:
So long as you make it clear for the laymen that the division of D by P is not the same as adding D and P (which total is always equal to the same value) then I think this will solve the problem. ...IMHO (Talk) 08:21, 30 June 2006 (UTC)
Another misunderstanding for laymen which this equation may encourage is that age of a sample as derived by the ratio of 14C is not a ratio of P to D but rather the ratio of archaeological 14C to current 14C. So long as this misunderstanding is cleared up then these writings may be comprehendible for the layman as well. ...IMHO (Talk) 08:50, 30 June 2006 (UTC)
- First:
- Your table, which was eventually called Transition of Carbon-14 to Nitrogen-14, reflected a major contradiction between its numbers and the narrative, precisely concerning the beta decay.
- E.g.: According to the table,
- (a) between Cycle 1 and Cycle 2:
- 5E+307 atoms of C14 decay into 1 single atom of N14. Where are the N14 missing atoms which amount to (5E+307)-1 ?
- ...
- Okay I see the problem now. No this is not what the table shows. The table shows that for each atom of 14C that decays via Beta emission a corresponding atom of 14N is created to take is place. If you add a third column which I realise from what you are saying that I should have done to show the total nomber of atoms then you get the identical value throughout the third column. My point here was just to show that atoms are indivisible and all that is happening is that the atom is only undergoing a change in name and characteristics. I think I made this clarification somewhere but I'll look for it again. ...IMHO (Talk) 11:35, 30 June 2006 (UTC)
- (b) between Cycle 1024 and Cycle 1025:
- 1 single atom of C14 decays into 1E+307 atoms of N14. Which process creates 1E+307 atoms of N14 out of a single atom of C14?
- Needles to repeat it again and again, as it has been said already, the number of C14-decayed + N14-created atoms at each cycle should remain equal and constant throughout the whole table if it is to reflect the correct physics. (From: Jclerman 16:18, 25 June 2006 (UTC))
- Second:
- The P and D values suggested to you, i.e. 4 and 16, neither imply nor evaluate to 100% parent isotope.
- These values were suggested by Vsmith not me. I have since used them as an index ranging from 0 to 20 to allow for a high number of atoms to be represented but if you only have 20 total atoms then use of 4 for the parent and 16 for the daughter as just one of twenty sets of values then it works out okay. ...IMHO (Talk) 11:35, 30 June 2006 (UTC)
- Third:
- The layman is expected to know arithmetic, hence that D/P is not equal to D+P.
- That assumes that the layman was not raised on a fishing vessel and was not required to attend any school or that the layman did not attend his grandmother's funeral on the day when this was explained in class. You have to pretend like the laymen knows absolutely nothing and then try to find a way to cover all of the bases for everyone. That is what makes the wiki such an important medium of publication because there is virtually an unlimited number of contributors from all different kinds of expertise and understanding and misunderstanding backgrounds who's interaction results naturally in a publication that covers all needs. This is why you have to tolerate other people editing your stuff. Its not easy I know but it is the way of the wiki. ...IMHO (Talk) 11:35, 30 June 2006 (UTC)
- Fourth:
- Now, can you plug 4, 16, and 8000, in the formulas and obtain the resulting age? --Jclerman 10:53, 30 June 2006 (UTC)
- I'm constructing several different tables based on the various interpretations and differences which we have discussed but before going further let me be sure we have the correct understanding now. You accept a total of 20 atoms starting with 20 14C and 0 14N and going to 0 14C and 20 14N for the values of P and D respectively, correct? ...IMHO (Talk) 11:35, 30 June 2006 (UTC)
- Let me suggest once more that if you do understand the formulas and the meaning of P, D, and lambda, you should be able to plug in 4, 16, and 8000, and obtain an age. No tables are requested or needed. Just one age obtained from each one of the formulas that you wish to evaluate for their correctness. Can you now plug 4, 16, and 8000, in those formulas and show the results you obtain? --Jclerman 12:05, 30 June 2006 (UTC)
- I think you are missing the point here. You have not clarified any of this in the article. You need to first clarify this in the article so that anyone who reads the article can comprehend the full meaning, relationship and purpose of P and D. Unitl you understand this it will serve no constructive purpose for me to follow through. ...IMHO (Talk) 12:22, 30 June 2006 (UTC)
- No, you are missing the point. You claimed an error in the equation, yet you seem incapable of simply plugging in numbers to check. No again, anyone reading the article may not comprehend the full meaning. A reasonable background is assumed. My 7 year old granddaughter no doubt would not comprehend. And you apparently don't comprehend, but the equation and article are accurate and reasonable. Wikipedia is not written for 2nd graders - a reasonable background is assumed for most articles, especially those of a technical nature.
- I assume that you lack the math ability to evaluate the equation with the simple numbers provided - as you have not done so and attempt to confuse the issue with unneeded tables and computer code. This obfustication of yours is getting tiresome. Oh, and 5568 is the value for the Libby half life of C-14 in case you were interested. Vsmith 13:47, 30 June 2006 (UTC)
Disection of age equation
We must complete a few more preliminaries before calculations can proceed.
First let me ask what role in your mind the following portion of the age equation plays?
What is the role played by the portion and what is the purpose of taking it's natural logarithm?.
What in your mind is the role plays since age may also be calculated by the following?
where
and inversely
where percent is defined by
Once you have explained each of the parts of the age equation requested above and commented on the merits of selecting or using one age equation over another I have several more questions regarding the relationship P has with D before calculations can be presented. ...IMHO (Talk) 16:21, 30 June 2006 (UTC)
Side bar
- Yor absurd waffle, We must complete a few more preliminaries before calculations can proceed.
- Nonsense. Just plug in the numbers and crunch, what is so difficult about that? To verify the answer, you need to realize that a D/P ratio of 4 (16/4) can be restated as a fraction remaining f of 0.2 for checking with the other equation (n=log 0.2/log 0.5). The equation is valid and referenced to a reliable source, you original charge Equation as published produces incorrect results is without merit. Stop the waffling and obfustication and use the numbers provided per your request. Vsmith 22:43, 30 June 2006 (UTC)
- Your statement that a ratio of D/P or (16/4) or 4 can be restated as p = 0.2 and used to check the other equation is incorrect. When we are talking about the ratio of D/P we are talking about apples whereas when we are talking about the ratio of are talking about oranges.
- Jclerman thought the values you provided for P and D were provided by me. There remain other misunderstandings between Jclerman and myself that need to be cleared up before we can proceed. Please stop injecting your comments so that we can proceed to resolve any misunderstandings we have between us without interruptions, interference or side bars. ...IMHO (Talk) 02:08, 1 July 2006 (UTC)
- The ratio D/P of 16/4 means that we started with 16 + 4 = 20 of P and now we have only 4 remaining. And 4/20 = 1/5 = 0.2 = f the fraction remaining for the equation (n=log 0.2/log 0.5). Both of these relationships apply to radiometric dating and are based on and use the same data (they are not apples and oranges).
- Jclerman knew where the numbers in question came from, read the discussion above again. Thanks for removing the butt out comment. This is a public discussion, if you want a private discussion then move it to your talk page please.
- Now, have you done the simple calculations? Vsmith 20:44, 1 July 2006 (UTC)
- Here is the problem: In a previous discussion
(which I am still searching for)Nice try. But... Jclerman said that 14C continues to decay Ad infinitum. The not-so conclusive radiocarbon dating I know this is a misconception and so do many others so where might someone as obviously knowledgeable as Jclerman get the idea that 14C continues to decay Ad infinitum? To find out requires a little bit of detective work and in this case a little bit of interaction in hope of revealing the source of his misunderstanding. The only purpose of the table I created was to demonstrate that 14C can in fact decay to a zero value. I also explained this in response to the example provided by Melchior: (10 atoms). Then by chance Jclerman replaced the age equation I had submitted with .
- Here is the problem: In a previous discussion
- Ah Ha! The source of the misunderstanding at last! Now if only there was a way to expose it. All of this was very subconscious mind you. I did not plan to replace the constant 1 with the variable n but rather it just happened like a subconscious shot in the dark and up to the point of your interruption Jclerman and I were getting closer to resolving his misunderstanding. Unfortunately your interruption brought this opportunity to an end so that the only choice I have now is to return to using a direct approach which might not give Jclerman the opportunity he needs to realize for himself the basis for his misunderstanding.
- I have prepared such a direct explanation but I was hoping that Jclerman might pickup and continue the discussion at the point prior to your injection but I have run out of time. If Jclerman still believes that 14C continues to decay Ad infinitum then I won't argue with him further. I'll just simply post what I feel is the reason for his misunderstanding here although I would have preferred that Jclerman be given and would have taken the opportunity to come to this understanding for himself. ...IMHO (Talk) 21:47, 1 July 2006 (UTC)
Please note at the bottom of the table that while can not be mathematically determined as the result of a divide by zero error when the value of P is zero (but is presumed to equal infinity) that P is in fact equal to zero when D is equal to 20. (BTW I no longer advocate replacement of the constant 1 with the variable n making calculations for it a mute point.) ...IMHO (Talk) 16:56, 2 July 2006 (UTC)
stop nonsense, please
Attn Pce3@ij.net aka IMHO:
You have been discussing the big bang and the biblical experiments on radioactive natural reactors and have been rebuked by everybody in many help desks and discussion pages. You have been dscussing also the scientists who hide intermediate results and those in the elitist towers of ivory, with about the same negative comments. Did you ever think that "others" might be correct in their assessments of your admittedly very creative approaches? BTW, we used to teach the hourglass model for radiocarbon dating already in the 1970s. See also comments below. --Jclerman 16:50, 5 July 2006 (UTC)
Attn unaware readers:
Follow the trail through the wikipedia help desks, policy boards, and the dicussion/talk pages of many related articles. They can be located by surfing the contribs list of User:Pce3@ij.net (who also signs as IMHO) during several weeks. Extensive discussions about dating formulas have ignored concepts such as asymptotes and exponentials, and the logical fact that nature's behavior can not be dictated by approximate and/or faulty formulas with, at best, restricted domain of validity. Physical phenomena can be approximated by mathematical expressions; however, mathematical expressions can not tell to the physical world how it is to behave. A layman's presentation of the hourglass model can be found in a web site of the USGS. Just search for "hourglass radiocarbon". See also comments above. --Jclerman 16:50, 5 July 2006 (UTC)
- You have tried to make connections which do not exist and you have failed to recognize the deliberate and extensive effort I have made to give you (and anyone else with your misconceptions) the benefit of understanding the basis for your miscomprehensions. Not only have you failed to appreciate this extraordinary effort but to deny that any miscomprehension exists. I suggest that you STOP STALKING, GROW UP and GO BACK TO SCHOOL! ...IMHO (Talk) 18:09, 5 July 2006 (UTC)
- Pce... please stop the nonsense. And please be be civil, your shouting of childish taunts do not belong in a civil discussion. The rather absurd calculations that you are trying to insert into the article fall under Wikipedia:Original research and for you to continue to attempt to push your OR POV by edit warring amounts to little more than vandalism. If you can find published concerns regarding the equation you are attempting to discredit, post the sources (note: as the equations and theory of radiometric dating have been well established in the scientific literature, only peer reviewed sources will carry much if any weight). --Vsmith 23:15, 5 July 2006 (UTC)
Straw poll
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 an unstable radioactive isotope is not replenished the isotope is never completely gone. It decays exponentially ad infinitum.
- All atoms of an unstable radiocative isotope in a sealed container without benifit of replenishment which undergo the process of Beta decay will eventually be gone.
- When the exponential decay calculation gives a result of less than one atom, the value calculated can be used to give a statistical probability that the last atom will have finally decayed (since random events do not follow a strict timeline.)
- This last point was added by Wdanwatts, but even it's not really correct. The point at which the average number of atoms remaining drops below 1 is not the same as the point at which the probability of zero atoms remaining surpasses 50%. The two are, unfortunately, not easily tied together (as far as I know). This problem emerges because the standard half-life model weights probabilities with the number of atoms. A sample calculation of this can be found in an earlier iteration of this discussion at [3]; note that while this case shows a >50% chance of no atoms, the expected number of atoms is not particularly close to a "good-looking guess" of 1 atom remaining or 0.5 atoms remaining. — Lomn | Talk 02:55, 7 July 2006 (UTC)
...IMHO (Talk) 00:24, 6 July 2006 (UTC
I would now like to thank everyone for their participation in this straw poll and ask that each of you post a statement beneath the "Summary statement" subsection above that will in their opinon best summarize and integrate the results of this straw poll into the article text proper for the benefit of readers by July 10, 2006 at 21:00 EST or July 11, 2006 at 00:00 UTC. Thanks again to everyone for your participation. The experience has been great! ...IMHO (Talk) 15:30, 7 July 2006 (UTC)
- This year the class was granted a choice between donating the money they earned along with the sponsorships they received to the Wikimedia Foundation or to pay for a field trip to a nuclear facility where they could talk with nuclear scientist and engineers. Rather than waiting until the last day of the straw poll the class unanimously voted to spend 100% of its funds on the field trip. Thank you for helping our students reach their decision and good luck next year. ...IMHO (Talk) 18:33, 9 July 2006 (UTC)