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Author Topic:   Creationist problems with radiocarbon dating
kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


(1)
Message 11 of 194 (556396)
04-19-2010 3:19 PM
Reply to: Message 1 by Coyote
04-19-2010 10:07 AM


RATE
quote:
Creation.com has the following in their "Age of the earth" page:

Radiometric dating
51. Carbon-14 in coal suggests ages of thousands of years and clearly contradict ages of millions of years.
52. Carbon-14 in oil again suggests ages of thousands, not millions, of years.
53. Carbon-14 in fossil wood also indicates ages of thousands, not millions, of years.
54. Carbon-14 in diamonds suggests ages of thousands, not billions, of years.

All four of these are absolutely wrong and reflect common errors passed from one creationist website to another.

If you want to debate these I'd be happy to oblige--on a different thread. Find one of the radiocarbon threads and post this and I'll show you where each is absolutely wrong.



I haven't looked into oil dates, and I'm not sure what their "fossil wood" refers to. But the coal and diamond claims relate to the ICR RATE project. I looked into these claims a few years ago, figured out how these folks had misinterpreted the data, and wrote up a detailed critique of the RATE radiocarbon claims. The report is available in at least three places on the web:
The American Scientific Affiliation
Reasons to Believe
TalkOrigins

Here is my summary:

Radioisotope evidence presents significant problems for the young earth position. Baumgardner and the RATE team are to be commended for tackling the subject, but their intrinsic radiocarbon explanation does not work. The previously published radiocarbon AMS measurements can generally be explained by contamination, mostly due to sample chemistry. The RATE coal samples were probably contaminated in situ. RATEs processed diamond samples were probably contaminated in the sample chemistry. The unprocessed diamond samples probably reflect instrument background. Coal and diamond samples have been measured by others down to instrument background levels, giving no evidence for intrinsic radiocarbon.

While some materials, e.g., coals and carbonates, often do show radiocarbon contamination that cannot be fully accounted for, resorting to intrinsic radiocarbon raises more questions than it answers. Why do only some materials show evidence of this intrinsic radiocarbon? Why does some anthracite and diamond exist with no measurable intrinsic radiocarbon? Why is its presence in carbonates so much more variable than in other materials, e.g., wood and graphite? Why is it often found in bone carbonates but not in collagen from the same bone? Since intrinsic radiocarbon would be mistakenly interpreted as AMS process background, why do multi-laboratory intercomparisons not show a much larger variation than is observed? Why does unprocessed diamond seem to have less intrinsic radiocarbon than processed diamond?

These and many other considerations are inconsistent with the RATE hypothesis of intrinsic radiocarbon but are consistent with contamination and background. Intrinsic radiocarbon is essentially a radiocarbon-of-the-gaps theory. As contamination becomes better understood, the opportunities to invoke intrinsic radiocarbon will diminish. Most radiocarbon measurements of old materials, including many of shells and coal, can be accounted for by known contamination mechanisms, leaving absolutely no evidence for intrinsic radiocarbon. The evidence falsifies the RATE claim that all carbon in the earth contains a detectable and reproducible ... level of 14C


This message is a reply to:
 Message 1 by Coyote, posted 04-19-2010 10:07 AM Coyote has responded

Replies to this message:
 Message 12 by Coyote, posted 04-19-2010 4:20 PM kbertsche has acknowledged this reply
 Message 13 by Flyer75, posted 04-19-2010 11:49 PM kbertsche has responded

    
kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


(1)
Message 15 of 194 (556467)
04-20-2010 1:07 AM
Reply to: Message 13 by Flyer75
04-19-2010 11:49 PM


Re: RATE
quote:
AIG made a response to your detailed critique found here: http://www.answersingenesis.org/...edback-rate-contamination

Sorry, but this is false. They did NOT respond to the critique that I referred you to. This shows that you have not read my critique. Please look at the dates on my critique and AiG's response. What AiG responded to was an earlier, much shorter critique that I had posted. The detailed critique that I linked to was written after their response, and incorporates critiques of their response as well as the original RATE report.
quote:
Obviously, yours (and Coyote's) knowledge of this subject is way beyond what I could ever even begin to comprehend. Two basic questions though....one, did you ever respond to AIG's response to you?

Yes, that's the link that I gave you! If you read it beside their response, you will see that I have addressed all of their technical points. They have yet to respond to my critique.
quote:
And two, how is the average joe blow out here who never works in this field supposed to know the truth? How do I know that you are right and AIG is wrong, or vice versa for that matter?

For the case at hand, they have not responded to my critique. And their earlier response is largely ad-hominem attacks and bald claims that they are correct. Note that they do not show where I'm wrong; they just claim that I'm wrong. In contrast, I tried to show how and where their analysis was wrong. And you can look at the spirit in which each report was done. I tried to avoid any personal attacks on Baumgardner or ICR, and to stick to a technical critique.

But in general, this is very difficult for a non-scientist to discern. The best way is to learn enough science to judge for yourself, but this takes time. The second best is to find a good scientist who you trust and ask his advice (a real working scientist, not someone on staff with ICR or AiG). The third best is to assume that mainstream scientists aren't stupid or naive, but have good reasons for their claims, so they are likely correct. If you are not comfortable with the mainstream scientific position but do not feel qualified to judge it, it is best to take a neutral position on the matter. It is dangerous and foolish to oppose the scientific mainstream if you are not a scientist.

quote:
Also, real quick and I hope this is the right spot to ask this, Henry Morris did a study a few years back that collected all the uniformitarian ways to rate the age of the earth, outside of radiocarbon dating (is that the right word?), and I think he came up with 66 or 67 other means, such as earth's magnetic field decay rate being one of them. He supposedly used chrisitian and secular sources for this study and of the 66, one could come up with an age older then just a few million years old, nothing close to the 4.5 billion that radiocarbon dating comes up with....is he dead wrong, am I wrong, or is there some truth to this? Thanks in advance for your answers.

I'm not familiar with this study. However, I suspect that he assumed too much "uniformity", assuming things are constant which we know are not. The earth's magnetic field is a classic example. It is now decaying slowly, and if extrapolated backwards at a uniform rate, would yield ridiculous values 4.65 billion years ago. But the geologic record shows us that the earth's magnetic field has actually flipped back and forth many times in a random, chaotic pattern. The assumption of a uniform magnetic field decay rate is wrong.

Edited by kbertsche, : No reason given.

Edited by kbertsche, : No reason given.


This message is a reply to:
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Replies to this message:
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kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


Message 17 of 194 (556486)
04-20-2010 2:08 AM
Reply to: Message 16 by Flyer75
04-20-2010 1:52 AM


Re: RATE
FYI, regarding Morris' uniformitarian estimates for the age of the earth, here's a simple "uniformitarian" estimate for the age of the earth that gets a bit closer to the topic of radiocarbon, though this is uranium rather than carbon. This will just give us an approximation, and is the type of simple "back-of-the-envelope" estimates that we do in physics. Let's start with the assumption that all heavy elements in the solar system came from supernova explosions. Let's further assume that the isotopes 235-U and 238-U were made in equal abundance. Now let's look at the current abundance of each and calculate an age. 235-U has a half-life of 703.8 MY, and accounts for 0.72% of natural uranium. 238-U has a half-life of 4.5 BY and accounts for 99.3% of natural uranium. From these abundances and half-lives, how long ago would they have been at equal abundance? The answer comes out to about 5.9 BY. We would expect the supernovas to be older than the earth, so this is not bad for an overly simplified back-of-the-envelope estimate.
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kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


(1)
Message 41 of 194 (556660)
04-20-2010 4:55 PM
Reply to: Message 31 by Dman
04-20-2010 3:19 PM


quote:
While discussing "young age" evidences with a creationist he presented this link to me: http://www.answersingenesis.org/...n-ages-for-ammonites-wood
Which he claimed as support of a young earth.

Here is the abstract:
...
I lack the knowledge to critique this with any merit. I was hoping to maybe get some feed back from those here at EvC with the proper knowledge to do so. This seemed like the appropriate thread.

Thanks.



To their credit, they explicitly spoke to the major errors that I identified in the RATE study:
Snelling writes:

However, the 14C measured in these fossils is well above the detection limit of the AMS instrument. Therefore the usual response to such a glaring and enigmatic discrepancy in absolute ages is to claim that the ammonite shells and wood were contaminated with modern carbon, either in the ground, or during sampling and in the laboratory. Four such sources of potential contamination were examined. In the laboratory the severe pre-treatment of the samples guarantees that any contamination from sampling and handling is totally eliminated. Then even if there were some contamination, as claimed by some, during the combustion and due to instrument background, the estimated 14C level involved would only be in the range 0.0050.069 pMC. This is a trivial amount of 14C that if conceded would make no difference whatsoever to the very much higher radiocarbon levels measured in these ammonite shells and wood fossils, particularly as the results reported by the IsoTrace Laboratory already have a laboratory background of 0.077 pMC subtracted from them.

Furthermore, potential contamination of the fossils by ground or surface waters while they were still entombed in the mudstones can be ruled out. Any such environmental contamination of the fossil wood would be removed by the severe sample pre-treatment in the laboratory. On the other hand, environmental contamination of the ammonite shells by replacement with modern carbonate 14C can be discounted, because the ammonite shells yielded almost identical 14C levels and apparent ages as the wood buried and fossilized with them.


I don't have time to do a detailed critique at the moment, but I'll just point out some concerns and questions regarding their claims:
1) They are measuring values very close to background levels, about 1% of modern levels. A 1% contamination from modern carbon would account for this.
2) Have they considered all of the possibilities for in-situ contamination? I doubt it. E.g., what is the geology of the mudstone; does it contain any radioactive isotopes that could create 14-C in situ? Did any of the samples absorb or adsorb CO2 after collection?
3) Shells can be easily contaminated in situ, because the inorganic carbonate molecules can slowly exchange carbon with their environment. They allude to this, and it is explained more fully in my RATE critique.
4) What does it mean that this wood was "fossilized"? Presumably it was hardened by mineral deposits. Do these minerals contain any carbon or carbonates? Could this undergo subsequent carbon exchange with their environment, similar to shells or bone? How confident are they that ALL carbon-containing minerals were removed by chemical pretreatment?
5) Their persistent claim that "extreme" sample pretreatment will "guarantee the elimination of any contamination" is not correct. More extreme pretreatments will generally ADD a small amount of modern contamination and will RAISE the effective background. This is partly because the additional chemicals and glassware have more chance of absorbing CO2 from the air.
6) "The laboratory (Beukens 2007 a, b) reported that the dried residues of the petrified wood sub-samples (RNCW-1, 2, 3, 4A) at this point in the procedure did not have any wood structure and resembled detrital material. ... their carbon contents were low (typically 10%)" This is a red flag; it means that none of the wood cellulose remained after pretreatment! (And I suspect that IsoTrace suggested at this point that the sample was not worth dating.) What was the "wood" material that they actually dated?
7) The IsoTrace "standard background" of 0.077 pMC was subtracted from all of these results. Is this really the correct value for BOTH the wood and the shells, which undergo very different sample chemistry? Is the correction only 0.077 pMC with all of the additional chemistry that was applied to the wood? I am very skeptical that all of these extra steps did not contribute to a significantly higher background.
This message is a reply to:
 Message 31 by Dman, posted 04-20-2010 3:19 PM Dman has responded

Replies to this message:
 Message 42 by Taq, posted 04-20-2010 5:09 PM kbertsche has responded
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kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


Message 48 of 194 (556781)
04-21-2010 3:18 AM
Reply to: Message 42 by Taq
04-20-2010 5:09 PM


quote:
If you are looking for a signal that is just barely above background you have to be extra careful with sample selection and prep.

Yes, and the best way to do this is to find a "radiocarbon-dead" sample of the same type of material and to prepare it in parallel with the unknown samples, using the same chemical reagents, the same batch of glassware, the same combustion and graphitization procedures, the same analysis run in the AMS system, etc. Then treat this "radiocarbon-dead" sample as a total process background to be subtracted. This way any surprises due to contaminated chemicals, dirty ion source, etc. are captured and subtracted out.

Unfortunately, the YECs cannot do this because they are stuck in a different paradigm. They don't believe the earth is old enough to have truly "radiocarbon-dead" material. So they don't do proper background subtractions and they fool themselves even further.


This message is a reply to:
 Message 42 by Taq, posted 04-20-2010 5:09 PM Taq has responded

Replies to this message:
 Message 49 by Taq, posted 04-21-2010 9:34 AM kbertsche has responded
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kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


Message 64 of 194 (557066)
04-22-2010 1:10 PM
Reply to: Message 58 by cavediver
04-21-2010 9:56 PM


Re: RATE
I also recommend the collection of critiques on various aspects of RATE on the ASA website:
http://www.asa3.org/ASA/education/origins/rate.htm

The conclusion of ASA Executive Director, Randy Isaac is strongly worded, but accurate:

Randy Isaac writes:

The ASA does not take a position on issues when there is honest disagreement among Christians provided there is adherence to our statement of faith and to integrity in science. Accordingly, the ASA neither endorses nor opposes young-earth creationism which recognizes the possibility of a recent creation with appearance of age or which acknowledges the unresolved discrepancy between scientific data and a young-earth position. However, claims that scientific data affirm a young earth do not meet the criterion of integrity in science. Any portrayal of the RATE project as confirming scientific support for a young earth, contradicts the RATE projects own admission of unresolved problems. The ASA can and does oppose such deception.


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kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


Message 65 of 194 (557140)
04-22-2010 11:44 PM
Reply to: Message 49 by Taq
04-21-2010 9:34 AM


quote:
Also, it would seem to me that even with a bouncy background you could at least use known concentrations of 14C to create a linear regression and extrapolate the background and measure the std. error. Anything within the std. error compared to background could be considered zero. Perhaps the problem here is that radiocarbon age is not represented by the amount of carbon 14 but by the calculated age which does not relate the data to the actual background in the experiment.

It's done pretty much the way you are thinking. Radiocarbon measurements are generally done by measuring radiocarbon ratios or concentrations (or a proxy for them), and this is where the backgrounds and normalizations are done. We would typically have at least one background radiocarbon-dead sample and at least one modern calibration standard for a set of unknowns. We would tune up the machine on a calibration standard and come back to it periodically during the run, and would also measure the dead samples a few times during the run. Then, as you imply, we could see how the backgrounds and calibrations varied throughout the run and could do linear fits between these known points. Only after all corrections are done is the result turned into a date BP, then this is converted to a calibrated BC/AD date.
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kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


Message 74 of 194 (557200)
04-23-2010 4:56 PM
Reply to: Message 69 by IchiBan
04-23-2010 1:27 PM


Re: Guess???
quote:
The truth is there are so many assumptions and variables these dating methods are based on the only scientifically honest answer is that they are an estimate/guess.

It is true that a number of approximations and corrections are used when doing radiocarbon dating. However, exactly the same approximations and corrections were used to derive the calibration curves. These approximations and corrections cancel out when dating an old piece of wood. In effect, what we are doing when we date an old piece of wood is to measure its radiocarbon concentration and to match this to a tree ring which has the same concentration.

The only remaining assumption is that we can count tree rings.

(Note: I can think of only one minor correction which does not exactly cancel for wood dating: the time difference between when the unknown sample is dated and when the tree rings were dated. The radiocarbon decay during this time difference must be corrected for. In practice, this is done by converting all radiocarbon concentrations to what they would have been in 1950.)


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kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


Message 80 of 194 (557223)
04-23-2010 11:05 PM
Reply to: Message 75 by Flyer75
04-23-2010 6:57 PM


quote:
Are or are there not some assumptions that come with this process? For example, nobody was around billions or millions of years ago to observe what the earth was going through at the time or what these samples went through as far as how they were affected by any sort of catastrophic event, and in discussing millions or billions of years, there's a good chance they went through quite a few catastrophic events, not just one.

As I said in Re: Guess??? (Message 74), the main assumption is that we can count tree rings. Any catastrophic events that affected the radiocarbon levels in the atmosphere would have been reflected in the tree rings used for calibration.

Some YECs have theorized that a global flood would have made a large change in the carbon balance and could affect our radiocarbon dates. But if this is true, we should see an abrupt slope change in the calibration curve. We do not see this over the last 45,000 years or so.

quote:
One example, how do we know for certain what the initial amounts were to begin with? Isn't that an assumption?

For Libby's original method, this was a necessary assumption. But with tree ring calibrations it is not--any changes in initial amounts are accounted for in the tree rings used for calibration.
quote:
Has the rate of decay changed at all during time? How can anyone know that for certain?

We understand nuclear physics well enough to believe that radioactive decay rates are fixed, constants that depend only on the nuclear structure. But if they are not, this would also be reflected in the tree rings used for calibration.

The bottom line: for samples of wood that are no more than about 12,000 years old (the length of the tree ring portion of the calibration curve), the tree ring calibrations remove most of the assumptions.


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kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


Message 81 of 194 (557226)
04-23-2010 11:35 PM
Reply to: Message 79 by Coyote
04-23-2010 9:11 PM


Re: Carbon 14 dating information
quote:
We do use assumptions in C14 dating, but fewer than you might expect. The primary one is that the decay constant has been constant. The other assumptions are generally things we can check on (see below):

Yes, this is true for uncalibrated dates. But since the same assumption is used in deriving the calibration curves, any changes in decay rate should be reflected in the calibration curves as well, and the changes should cancel out for calibrated dates.

I suppose we make an assumption that the atmospheric concentration was uniform around the globe, but this is a fairly good assumption for each hemisphere of the earth. There is a slight latitude dependence, and possibly a slight regional dependence. But we also have multiple calibration curves (N America, Europe, and Near East), so we can make these slight corrections if necessary.

quote:
This site, BiblicalChronologist.org has a series of good articles on radiocarbon dating.

And the YECs should note that Gerald Aardsma, who runs this site, is a fellow YEC who was formerly on staff at ICR. But he was trained at a leading radioisotope laboratory (IsoTrace--the same lab that ICR uses for their samples), he understands radiocarbon, and he believes it is accurate.
This message is a reply to:
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kbertsche
Member
Posts: 1062
From: San Jose, CA, USA
Joined: 05-10-2007


(1)
Message 93 of 194 (642249)
11-27-2011 12:15 AM
Reply to: Message 88 by Pollux
11-26-2011 7:12 AM


Re: Snelling's experiments
quote:
I have been having an on-line discussion with a YLC who brought up Snelling's test on fossilised wood in old deposits. A google check for radiocarbon in fossil wood only turned up Snelling's reports for the relevant age formations. I see the possible sources of error mentioned. Is it known whether anyone has done tests to refute Snelling? I understand that no significant C14 is expected in deposits millions of years old, so it is not likely anyone would bother.
I was helped to an understanding of the age of the Earth by EvC Forum, especially Razd's excellent Correlations thread, and Daniel Wonderly's "Neglect of Geologic Data by Creationists" which I heard of here. So thanks to all!

I met Dan Wonderly many years ago, and was very impressed by him. He was a godly, approachable, humble person.

You might also take a look at the paper on radiometric dating by Roger Wiens, if you aren't already familiar with it.

FYI, I suspect the fossil wood has been deteriorated and contaminated by its environment. The best way to date old potentially contaminated wood is to chemically separate the cellulose and date only the cellulose. But if the wood is too deteriorated this is not always possible.


"Science without religion is lame, religion without science is blind." Albert Einstein

I am very astonished that the scientific picture of the real world around me is very deficient. It gives us a lot of factual information, puts all of our experience in a magnificently consistent order, but it is ghastly silent about all and sundry that is really near to our heart, that really matters to us. It cannot tell us a word about red and blue, bitter and sweet, physical pain and physical delight; it knows nothing of beautiful and ugly, good or bad, God and eternity. Science sometimes pretends to answer questions in these domains, but the answers are very often so silly that we are not inclined to take them seriously. Erwin Schroedinger


This message is a reply to:
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