Message 151 of 221 (436862) 11-27-2007 8:47 PM

I read his reply, and the responses, but John has said little new after that.

http://www.theologyweb.com/campus/showthread.php?t=103916

quote:

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So how does the radiocarbon community deal with this state of affairs? Even to the casual observer, the presence of significant levels of 14C, which has a half-life of only 5730 years, in biological samples which are supposed to be tens or hundreds of millions of year old cries out for explanation.

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No it doesn't, this is hyperbole. There are several existing explanations for this problem.

One must always remember that radiocarbon dating is based on the C12 and C14 coming from atmospheric carbon, where the C14 is due to solar activity converting N14 to C14. There are other sources of carbon and other ways to make C14 (C13 can be converted during nuclear reactions, as can "expired" C14 having again become N14 in the samples). These would necessarily be rare events in buried samples, and thus produce only low levels of new C14, such as those found in coal and diamonds in the RATE paper.

Thus when anything is dated - particularly samples over 50,000 years - by this method it is imperative to eliminate other sources for carbon and for production of new C14. A background level of radiation will produce a background level of C14 with the level depending on the level of radioactivity involved.

This is well known by Baumgardner et al, and thus it is no surprise that they make use of this fact. It is relatively easy to search out radioactive sites and intentionally find samples that appear to throw dating into question.

The problem for these people is that even if such "contamination" of samples is common in the world of archaeological samples that do come from sources that obtained their C12 and C14 from atmospheric carbon, that the level of error produced is still within the margin of error for the dating methods, and radioactivity can be eliminated in most cases relatively easily. Take the Lake Suigetsu clay\diatom varves, with some 35,000 annual layers and samples of organic debris found in the layers: because of the manner of formation of the varves there is no source of radioactivity that could change the age of those samples, and the varve layer age would still correlate with the radiocarbon date properly.

Even if the level of C14 in very old samples is due to cosmic radiation penetrating the earth, the level produced is necessarily small as there is limited material to convert to C14 (C13 and N14 being is very small quantities).

The end result either way is that the system cannot be used to date things much older than 50,000 years with the accuracy that samples younger than 50,000 years have. That is not a hardship.

It does not show that coal or diamonds are young, nor that radiocarbon dating is filled with massive errors.

Enjoy,

Edited by RAZD, : .

Edited by RAZD, : not nothing

Message 153 of 221 (437095) 11-28-2007 8:36 PM

Reply to: Message 152 by Chiroptera 11-27-2007 11:35 PM

http://radiocarbon.library.arizona.edu/radiocarbon/

On-line access to radiocarbon issues from 1959 to 2004.

And three additional articles on Lake Suigetsu, and a couple on the Cariaco Basin that provide another correlation, this one provided by John:

http://geopubs.wr.usgs.gov/prof-paper/pp1670/pp1670.pdf

Yep, but then when you are trying to defend a false position it is hard to use real evidence.

Enjoy.

Message 155 of 221 (442904) 12-22-2007 11:50 PM

Reply to: Message 1 by sailorstide 05-01-2006 12:12 AM

1. the earths atmosphere has reached equilibrium

2. and c14 has always burned at a constant rate

Message 156 of 221 (442909) 12-23-2007 12:07 AM

Reply to: Message 155 by sikosikik5 12-22-2007 11:50 PM

Both of your "concerns" have already been discussed at length.

Message 157 of 221 (442998) 12-23-2007 11:43 AM

Reply to: Message 155 by sikosikik5 12-22-2007 11:50 PM

Nope.

(1) we know that the production of 14C varies from year to year due to the solar sunspot cycle, and thus the amount will always vary about an average, and never reach an "equilibrium. We can, hoverver, assume that we can use average over the 11 year cycle applies with sufficient accuracy for dating purposes. Then we can check radiocarbon dating based on this assumption against items where we know the dates from other methods and see if the assumption holds up. This has been done, resulting in a correlation curve. See IntCal04 (ToC) and related articles through Radiocarbon archives for details. You can also look at IntCal98 for similar calibration work.

(2) Carbon-14, 14C, does not "burn" - it is radioactive and decays along an exponential curve based on its half-life (5730 years). We have found no reason to believe that radioactive rates have changed in the past, no evidence for it, even though this has been considered.

If someone tells you different, the likelihood is either (1) they are ignorant themselves, (2) they are lying to deceive you, (3) they are deluded about reality.

Enjoy.

ps - as you are new: type [qs]quotes are easy[/qs] and it becomes:

or type [quote]quotes are easy[/quote] and it becomes:

quote:

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quotes are easy

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also check out (help) links on any formating questions when in the reply window.

Message 158 of 221 (457877) 02-26-2008 1:21 AM

Reply to: Message 154 by Chiroptera 11-30-2007 7:51 PM

An expanded analysis of the RATE claims, about 5x longer, is also available here:
http://www.asa3.org/ASA/education/origins/carbon-kb.htm

Kirk Bertsche

Message 159 of 221 (503830) 03-22-2009 6:16 PM

Reply to: Message 157 by RAZD 12-23-2007 11:43 AM

This thread is now closed due to length, however this choice piece of typical creationist misrepresentation of carbon-14 dating problems should be addressed.

There never will be an "equilibrium" level of C-14 in the atmosphere.

The reasons are simple, but the failure (ignorance, misunderstanding, intentional misrepresentation, whatever) to come to terms with this simple fact betrays a lack of learning the simple basics of the method and the reasons for the variations.

The Carbon-14 Environment

Carbon-14 is a radioactive isotope of carbon.

http://www.infoplease.com/ce6/sci/A0857174.html (1)

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Carbon has 13 known isotopes, which have from 2 to 14 neutrons in the nucleus and mass numbers from 8 to 20. Carbon-12 was chosen by IUPAC in 1961 as the basis for atomic weights; it is assigned an atomic mass of exactly 12 atomic mass units. Carbon-13 absorbs radio waves and is used in nuclear magnetic resonance spectrometry to study organic compounds. Carbon-14, which has a half-life of 5,730 years, is a naturally occurring isotope that can also be produced in a nuclear reactor.

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http://www.c14dating.com/int.html (8)

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Three principal isotopes of carbon occur naturally - C-12, C-13 (both stable) and C-14 (unstable or radioactive). These isotopes are present in the following amounts C12 - 98.89%, C13 - 1.11% and C14 - 0.00000000010%.

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http://science.howstuffworks.com/carbon-14.htm/printable (5)

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Cosmic rays enter the earth's atmosphere in large numbers every day. For example, every person is hit by about half a million cosmic rays every hour. It is not uncommon for a cosmic ray to collide with an atom in the atmosphere, creating a secondary cosmic ray in the form of an energetic neutron, and for these energetic neutrons to collide with nitrogen atoms. When the neutron collides, a nitrogen-14 (seven protons, seven neutrons) atom turns into a carbon-14 atom (six protons, eight neutrons) and a hydrogen atom (one proton, zero neutrons). Carbon-14 is radioactive, with a half-life of about 5,700 years.

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This takes energy to accomplish, and the decay releases this energy: Carbon-14 decays back to Nitrogen-14 by beta^- decay:

http://education.jlab.org/glossary/betadecay.html (7)

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Click to enlarge

During beta-minus decay, a neutron in an atom's nucleus turns into a proton, an electron and an antineutrino. The electron and antineutrino fly away from the nucleus, which now has one more proton than it started with. Since an atom gains a proton during beta-minus decay, it changes from one element to another. For example, after undergoing beta-minus decay, an atom of carbon (with 6 protons) becomes an atom of nitrogen (with 7 protons).

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Thus cosmic ray activity produces a "Carbon-14 environment" in the atmosphere, where Carbon-14 is being produced or replenished while also being removed by radioactive decay due to a short half-life. This results is a variable but fairly stable proportion of atmospheric Carbon-14 for absorption from the atmosphere by plants during photosynthesis in the proportions of C-12 and C-14 existing in the atmosphere at the time.

The level of Carbon-14 has not been constant in the past, as it is known to vary with the amount of cosmic ray bombardment and climate change.

Because the level of cosmic ray radiation level is always changing, based on several independent cycles (one is 19 years long), there will never be a point where the level of 14C is in equilibrium. Instead the level of 14C will rise and fall, lagging behind but in response to the rise and fall of cosmic ray radiation levels. It will never reach a steady level.

Anyone who tells you it should be in equilibrium is either lying or doesn't understand how 14C is produced and how equilibrium is reached.

Enjoy.

Message 160 of 221 (503875) 03-23-2009 12:01 AM

Reply to: Message 159 by RAZD 03-22-2009 6:16 PM

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This apparent age of oceanic water is caused both by the delay in exchange rates between atmospheric CO2 and ocean bicarbonate, and the dilution effect caused by the mixing of surface waters with upwelled deep waters which are very old (Mangerud 1972). A reservoir correction must therefore be made to any conventional shell dates to account for this difference. Reservoir corrections for the world oceans can be found at the Marine Reservoir Correction Database, a searchable database online at Queen's University, Belfast and the University of Washington.

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reference

Message 161 of 221 (503876) 03-23-2009 12:42 AM

Reply to: Message 160 by shalamabobbi 03-23-2009 12:01 AM

http://www.answersingenesis.org/articles/nab/does-c14-disprove-the-bible

Because their religious belief tells them that radiocarbon dating is in error, they look for any possible facts or quotes to misrepresent or misunderstand in order to confirm that belief. This web article is a very good example.

As is often the case with creationist websites, it makes junk science seem downright respectable.

As is generally the case with creationist "science" this article is inaccurate.

Message 162 of 221 (504283) 03-26-2009 10:36 AM

Reply to: Message 161 by Coyote 03-23-2009 12:42 AM

quote:

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The "equilibrium problem" comes from websites like AnswersinGenesis:
http://www.answersingenesis.org/articles/nab/does-c14-disprove-the-bible

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But with tree ring calibrations, equilibrium does NOT need to be assumed. The only assumptions are that 1) we can count annual tree rings, and 2) the trees used for calibration and the unknowns breathed the same atmospheric radiocarbon. There is NO assumption of equilibrium, original concentrations, etc. (BTW, this also gets around any claims of changes in the decay rate.)

These details are mostly unknown by YECs, who persist in claiming that radiocarbon rests on many unproven assumptions. I was quizzed on this just last week by a fairly knowledgeable YEC, who seemed surprised by these details.

Edited by kbertsche, : No reason given.

Message 163 of 221 (504310) 03-26-2009 7:19 PM

Reply to: Message 162 by kbertsche 03-26-2009 10:36 AM

One also needs to consider the history of carbon-14 dating:

http://home.tiac.net/~cri/1999/c14hist.html

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1941: Thellier proposed that Earth's magnetic field experiences secular variations.

1949: Arnold and Libby publish radiocarbon dates of items of known age.

1952: Libby publishes first book on radiocarbon dating.

1954: Forbush observed that the 11-year cycle of sunspot activity was inversely correlated with cosmic-ray intensity.

1955: Suess proposed dilution due to the burning of fossil fuels for the 2% depletion of 14C activity seen in 20th century wood compared to 19th century wood.

1956: Elasser, et al. predicted variations in the cosmic ray flux due to secular variations in Earth's magnetic field.

1958: de Vries found that 17-th century wood had a 2% higher activity than 19th century wood.

1961: Stuiver used historical records of sunspot activity to calculate cosmic ray intensity, and hence 14C production for the past 1500 years, and suggesting that the observations of de Vries, correlated with a sunspot minimum.

1965: Stuiver used more detailed records to confirm the correlation of a sunspot minimum with de Vries observations.

1967: Bucha and Neustupny provided paleomagnetic intensity measurments that supported the existence of secular variations in the Earth's magnetic field first proposed by Thellier. They were able to model the variations of 14C production, and almost exactly match the deviations between the tree-ring and radiocarbon time scales.

By 1969, enough radiocarbon dates of objects of known age, it became apparent that calibration of the 14C dating method was both possible, and required, to make radiocarbon dates useful for the determination of calendar dates. Indeed, it is often material from prior to 1969 that creationists use as ammunition against the 14C dating method.

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Creationists using old information when science has developed significantly since then? Shocking.

What this shows is that (A) the assumption of a constant level was reasonable at the beginning, and (B) it still works due to the variation in 14C production being cyclical around an average value.

http://www.c14dating.com/int.html

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The radiocarbon method was developed
by a team of scientists led by the late Professor
Willard F. Libby of the University of Chicago in immediate post-WW2 years.
Libby later received the Nobel Prize in Chemistry in 1960:

"for his method to use Carbon-14 for age determinations in archaeology, geology, geophysics, and other branches of science.""

According to one of the scientists who nominated Libby as a candidate for this honour;

"Seldom has a single discovery in chemistry had such an impact on the thinking of so many fields of human endeavour. Seldom has a single discovery generated such wide public interest."

(From Taylor, 1987).

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Message 164 of 221 (507921) 05-08-2009 11:11 PM

quote:

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I have read that radiocarbon dating is based on several faulty assumptions. Even if one of those are contentions are correct then the method of dating is unreliable. I would find it hard to believe that with the universe changing over billions of years that anything would remain constant. You would have to admit Can the universe evolve and remain constant at the same time?

The Big Bang and Licoln's assassination aren't really comparable. There are several documented eye witness accounts of the wound and his death.

How do you refute these questions the ID crowd have around the accuracy of carbon dating?

I really appreciate your tone in this discussion. I just have questions.

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1) When you say "radiocarbon dating" you probably mean "radiometric dating." Radiocarbon dating is one of the most familiar forms of radiometric dating, but it extends back in time only about 50,000 or 60,000 years. And, it works only on those things which contain carbon. But since you asked about radiocarbon dating, and that is something I have worked with a lot over nearly 40 years as an archaeologist, I will address that one method.

2) You probably read that radiocarbon dating was based on several assumptions, and the creationist source you read implied that those assumptions were faulty. Actually, none have been shown to be faulty by creation "science" or even real science.

Radiocarbon dating relies on the assumptions that a) the decay constant has remained constant over the 50,000 or 60,000 years that the method addresses, and that b) the initial amounts of radiocarbon are known.

a) There is currently no evidence that the decay constant varies by any significant amount. This is established by physicists and other scientists, not by "evolutionists" who are out to "prop up" Darwin's theory.

But a few years ago creation "scientists" gathered over a million dollars of creationist money and set out to "prove" the decay constant wasn't. The R.A.T.E. Project, as it was known, failed. They found that scientists were right all along, but they refused to believe their own data. Creationists can't accept scientific data because they have chosen to accept scripture as the highest form of knowledge, so they had to reject the data they themselves generated! Creation "science" as usual, eh? Source: Assessing the RATE Project: Essay Review by Randy Isaac

b) Creationists make a big deal out of the fact that atmospheric levels of carbon 14 vary because of variations in cosmic rays and other factors. They use this to cast doubt on the accuracy of the method. But don't you think scientists have noticed this variation and dealt with it? De Vries, in 1958, published on this problem and proposed solutions. Since then, a calibration curve has been established for North America using dated tree rings from the standing dead bristlecone pines of the White Mountains of southern California. That curve differs by only a bit over 10% at its greatest from the measured radiocarbon ages. But just in case that calibration curve is not representative, other curves have been worked out. They have used oaks in Europe and even coral growth and glacial varves in lakes, and the answers all come out pretty much the same.

So in answer to your question, radiocarbon dating is not based on several faulty assumptions. The assumptions are as accurate as science can make them.

What is faulty is creationists' efforts to discredit particular sciences because their religious belief requires it. For the most part they know little about science, but think they can overturn entire fields based on their faulty understanding and a few "gotcha" points that are repeated over and over. Those points have also been refuted over and over, and are thus called PRATTs (points refuted a thousand times). This is what you have most likely read.

And check earlier posts on this thread. If I remember correctly there will be a lot of good information for you. If you have any specific questions, let us know. There are several folks here who are quite knowledgeable in this field.

Edited by Coyote, : Boo-boo

Message 165 of 221 (508080) 05-10-2009 12:23 PM

This is one thread where you can discuss what you think are problems with dating methods, specifically what you think is wrong with 14C dating.

In Message 1 you say:

You can believe what you like, unfortunately (for your) it has no effect on reality.

The earliest agricultural evidence is circa 10K years ago:

http://en.wikipedia.org/wiki/Neolithic_Revolution

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The Neolithic Revolution was the first agricultural revolution—the transition from hunting and gathering communities and bands, to agriculture and settlement (settlement is currently being questioned). Archaeological data indicate that various forms of domestication of plants and animals arose independently in at least 7-8 separate locales worldwide, with the earliest known developments taking place in the Middle East around 10,000 BC (BCE) or earlier.[1]

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That makes the evidence of agriculture older than your YEC world. It is not the only thing older than your YEC world (see Age Correlations and An Old Earth, Version 2 No 1 for a number of things that make your YEC concept invalid).

Seeing as 14C (not Co14 -- there is no 14Cobalt isotope, Cobalt - Co - has 27 protons) is vastly validated as a method of determining dates, including correlations with annual layer systems that extend to 35K+ years, and 45k to 50k years is the practical limit for using 14C dating.

Modern humans are closer to 200,000 years old on this planet.

http://www.berkeley.edu/news/media/releases/2003/06/11_idaltu.shtml

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BERKELEY - The fossilized skulls of two adults and one child discovered in the Afar region of eastern Ethiopia have been dated at 160,000 years, making them the oldest known fossils of modern humans, or Homo sapiens.
...
The sediments and volcanic rock in which the fossils were found were dated at between 160,000 and 154,000 years by a combination of two methods. The argon/argon method was used by colleagues in the Berkeley Geochronology Center, led by Paul R. Renne, a UC Berkeley adjunct professor of geology. WoldeGabriel of Los Alamos National Laboratory and Bill Hart of Miami University in Ohio used the chemistry of the volcanic layers to correlate the dated layers.

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And that doesn't even begin to touch the age of ancestor species of hominids.

Note that 14C was not used, but two independent methods, one radiometric and one chemical, and the dates of the two methods agreed.

This is the common approach to any find - using different methods and comparing results. What this means is that you need to explain how both methods can be exactly wrong by precisely the same amount.

Now, perhaps, you would like to present us with the information that you think makes 14C dating invalid.

Provide sources and quotes, not just assertions, as this is a science thread and you have been challenged to provide scientific evidence.

Good luck.

Enjoy.