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Author Topic:   Peanut Gallery for Great debate: radiocarbon dating, Mindspawn and Coyote/RAZD
RAZD
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Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 1 of 305 (710796)
11-11-2013 7:59 AM


The debate has begun, and, as we usually have a thread to comment on the posts, I propose these guidelines:

  1. Great Debate participants -- Coyote and Mindspawn -- should not post comments here, they have the GD thread for making their case.
  2. Participants here should limit their comments to the contents of the posts on the GD thread.

Enjoy

Edited by RAZD, : update title


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Replies to this message:
 Message 2 by RAZD, posted 11-11-2013 8:27 AM RAZD has responded

  
RAZD
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Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 2 of 305 (710797)
11-11-2013 8:27 AM
Reply to: Message 1 by RAZD
11-11-2013 7:59 AM


Great Debate Message 3
in Message 3 mindspawn claims:

My main problem with carbon dating is its calibration against tree ring chronology, which I feel is unreliable due to assumptions about the annual nature of rings. Tree growth is normally relative to moisture, and moisture cycles are not always annual:

We see in the above quote that variation in precipitation is often the main cause of variation in tree growth. In areas with only rare rainfall and well drained soils, there is no reason to assume the rings would be annual. The rings in arid areas are precipitation sensitive, and this is compounded by well drained soils. So if a region receives sporadic rainfall, and this water completely drains out the soil until the next rainfall, this would cause rings that are not annual, but are sensitive to every significant rainfall. The growth occurs while the soil is wet, and stops when the soil drains out.

Curiously, the comments by Dr. Henri D. Grissino-Mayer quoted refer to why growth rings have varying widths:

quote:
The Principle of Limiting Factors

As used in dendrochronology, this principle states that rates of plant processes are constrained by the primary environmental variable(s) that is most limiting. ...


The variation in ring width is a separate issue from the occurrence of growth rings in ecologies with very distinct annual changes, such as winter and summer on top of the Sierra Nevada mountains, or where deciduous trees have leaves that die in an annual cycle, such as the Oaks in Ireland and Germany.

This, of course, is also why certain species and growth areas are selected over others when a dendrochronology system is determined for providing age data.

In addition Mindspawn fails to go on and quote Dr. Henri D. Grissino-Mayer on how the problems he points out are dealt with in making a good dendrochronology.

http://web.utk.edu/~grissino/principles.htm#3

quote:
The Principle of Aggregate Tree Growth

This principle states that any individual tree-growth series can be "decomposed" into an aggregate of environmental factors, both human and natural, that affected the patterns of tree growth over time. For example, tree-ring growth (R) in any one year (indicated by a small "t", where t could be "1" for year 1, and "2" for year 2, etc.) is a function of an aggregate of factors:

1. the age related growth trend (A) due to normal physiological aging processes
2. the climate (C) that occurred during that year
3. the occurrence of disturbance factors within the forest stand (for example, a blow down of trees), indicated by D1,
4. the occurrence of disturbance factors from outside the forest stand (for example, an insect outbreak that defoliates the trees, causing growth reduction), indicated by D2, and
5. random (error) processes (E) not accounted for by these other processes

The Principle of Site Selection

... This principle states that sites useful to dendrochronology can be identified and selected based on criteria that will produce tree-ring series sensitive to the environmental variable being examined. ...


There is more on how cross-dating, replication and other methods are used to generate a good dendrochronology.

The conditions cited for poor growth ring data do not apply, for instance, to the Bristle-cone Pine high in the Sierra Nevada mountains, nor to the deciduous Oak trees in Ireland and Germany.

The problem for mindspawn is that he doesn't have to just question the accuracy, but he needs to show that the dendrochronologies are in fact inaccurate.

Given that the Bristle-cone Pine dendrochronology from Sierra Nevada, the Oak dendrochronology from Ireland, and the Oak dendrochronology from Germany agree within 0,5% over 8,000 years of record, what mindspawn needs to demonstrate what specific type of events could affect each dendrochronology in exactly the same way in spite of them being in 3 diverse locations in the world and two different types of trees (one pine -evergreen- and the other oak -deciduous), and two significantly different ecologies.

It is the correlations that show that the chronologies are accurate.

Edited by RAZD, : finishing

Edited by RAZD, : subtitle

Edited by RAZD, : full name


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This message is a reply to:
 Message 1 by RAZD, posted 11-11-2013 7:59 AM RAZD has responded

Replies to this message:
 Message 4 by RAZD, posted 11-11-2013 11:18 AM RAZD has responded

  
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


(1)
Message 4 of 305 (710825)
11-11-2013 11:18 AM
Reply to: Message 2 by RAZD
11-11-2013 8:27 AM


Re: Great Debate Message 3 and Don Batten
Further information on how Creationists tend to misuse information is found here: Dendrochronology Fact and Creationist Fraud, Message 1.

Purposefully selecting a tree species and ecology that are known to have false rings does not prove dendrochronology wrong -- to do that the creationist needs to show that the conditions for false rings actually pertain to the trees used in the specific dendrochronology and document when they occurred.

When Dr Grissino says ...

http://web.utk.edu/~grissino/principles.htm#3

quote:
... Therefore, to maximize the desired environmental signal being studied, the other factors should be minimized. For example, to maximize the climate signal, the age related trend should be removed, and trees and sites selected to minimize the possibility of internal and external ecological processes affecting tree growth.

... he is saying that different trees and ecological sites can be chosen to suit different studies, age in one case, climate in another ...

... and -- in the case of "Dr" Batton -- misusing one for the other will result in known problems, and when those known problems are not corrected, this creates misinformation and fraud rather than honest scientific criticism.

Enjoy


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This message is a reply to:
 Message 2 by RAZD, posted 11-11-2013 8:27 AM RAZD has responded

Replies to this message:
 Message 5 by RAZD, posted 11-11-2013 9:09 PM RAZD has acknowledged this reply

  
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


(1)
Message 5 of 305 (710860)
11-11-2013 9:09 PM
Reply to: Message 4 by RAZD
11-11-2013 11:18 AM


Re: Great Debate Message 4 and Correlations
In Message 4 of the Great debate: radiocarbon dating, Mindspawn and Coyote Coyote responds with:

quote:
The idea of a calibration using tree rings or these other materials is to correct for atmospheric fluctuations in the levels of C14. So, let's not correct for atmospheric fluctuations (even though creationists are constantly telling us we have to make such corrections). What do we get without these corrections?

During the past 10,000 or so years the uncalibrated ages are off by about 10% at the most extreme. The error gets a little larger up around 30,000 years ago. This shows quite clearly on the calibration curve.

The calibration curve has been posted here many times, ...

What this shows is that even if we totally ignore the tree rings and other methods of establishing atmospheric fluctuations, and do no calibration, we still get old dates ...


What Coyote is saying is that even without calibration there is a correlation between actual age and the age calculated from measured C14 levels based on the exponential decay curve for C14.

The issue is correlations, whether the source data is tree rings, lake varves, coral, etc.

One of the questions that should be asked by anyone skeptical of dendrochronology is whether there are any other correlations than C14 age that talk to the accuracy of the dendrochronology.

The answer, not too surprisingly, is yes. In Message 4 of Age Correlations and An Old Earth, Version 2 No 1 -- after showing that the error found between three separate dendrochronologies was only 37 years in 8,000 years of record (a little under 0.5% error) -- we see the introduction of C14 to the dendrochronology discussion.

Because C14 is radioactive and decays along an exponential curve, it would take some real effort on the part of creationists to explain how low levels of C14/C12 could occur without age, but the kicker is not the decay age calculation itself, but how C14 is produced in the atmosphere:

quote:
Message 4 of Age Correlations and An Old Earth, Version 2 No 1: http://science.howstuffworks.com/carbon-14.htm/printable (5)

quote:
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.

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.


Coyote showed a calibration curve to demonstrate how C14/C12 ratios correlate with age based on a variety of sources including, but not limited to, tree rings. The kicker is in those jagged teeth in the curve. As noted above C14 is produced by cosmic ray bombardment from the sun, and this varies over an 11 year cycle:

quote:
Message 92 of Age Correlations and An Old Earth, Version 2 No 1: ... but there is another cycle that is of even more interest in terms of correlations:

quote:
http://en.wikipedia.org/wiki/Solar_cycle

The solar cycle (or solar magnetic activity cycle) has a period of about 11 years. The cycle is observed by counting the frequency and placement of sunspots visible on the Sun. Solar variation causes changes in space weather and to some degree weather and climate on Earth. It causes a periodic change in the amount of irradiation from the Sun that is experienced on Earth.


This results in a similar cycle pattern in the amount of 14C in the atmosphere, and is one of the reasons that C14 does not reach an equilibrium point in the atmosphere (another creationist pratt down the tubes ... ).

You can see this pattern in the calibration curves, causing the fine saw-tooth pattern:

There are other known period cycles that also have a similar effect, but the point of interest for the correlations, is that this is like a ticking clock with a fixed period of each tick, and they continue throughout the whole curve.


This is a basic mechanism in the sun, an independent correlation that validates the ages.

Enjoy


we are limited in our ability to understand
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Rebel American Zen Deist
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This message is a reply to:
 Message 4 by RAZD, posted 11-11-2013 11:18 AM RAZD has acknowledged this reply

Replies to this message:
 Message 6 by Diomedes, posted 11-11-2013 10:20 PM RAZD has responded

  
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 8 of 305 (710878)
11-12-2013 7:35 AM
Reply to: Message 6 by Diomedes
11-11-2013 10:20 PM


Re: Great Debate Message 5 and Cognitive Dissonance
Coyote pretty much just performed a first round knockout.
I find it absolutely fascinating that people can still dispute this sort of thing. ...

We'll see. It's not easy for people with firmly held beliefs to accept when they are falsified.

Message 5 of the GD: Coyote I haven't got time to read up in the peanut gallery, and I wont be referring there often at all. This is a one on one debate, if you feel there are good points made there, could you kindly make those points here in this forum. At this stage you have given no argument to my point about tree rings.

This is one way to deal with cognitive dissonance: ignore other information that is dangerous to your beliefs. Midspawn has consistently ignored the Age Correlations and An Old Earth, Version 2 No 1 even though he has been invited there on several occasions.

Message 5 of the GD: The calibration curve you have presented is merely circular reasoning. Sure all of them present the same dates, but they use carbon dating to find the dates. You cannot use carbon dates to prove carbon dates, that is circular reasoning.

Another method of dealing with cognitive dissonance is to try to discredit the information that conflicts with your cherished beliefs.

This comment is, of course, a false claim, but one you commonly see on creationist websites.

The curve shown has dates derived from C14/C12 ratio measurements on one axis and dates derived from other methods on the other axis.

quote:
Message 4 of Age Correlations and An Old Earth, Version 2 No 1: These calibration curves have been extended now to the limits of Carbon-14 dating, but it is also of interest to look at just the Carbon-14 calibration curve for dendrochronology - the results of matching tree-rings to Carbon-14 levels and their implied "C-14 age":

http://www.ipp.phys.ethz.ch/...arbon/HajdasPhDthesis1993.pdf (9)

quote:


In this case tree rings on one axis, C14 age calculations on the other axis.

quote:
Message 5 of Age Correlations and An Old Earth, Version 2 No 1: In the case of the Lake Suigetsu Lake Varves they present a calibration curve as well, and we can use this to represent the Carbon-14 environment in the same way we did for the tree-rings - as an indicator of what the levels of Carbon-14 were when the organic samples were alive and growing.

http://www.sciencemag.org/cgi/content/abstract/279/5354/1187 (3)

quote:

Fig. 1. (A) Radiocarbon calibration up to 45,000 yr B.P. reconstructed from annually laminated sediments of Lake Suigetsu, Japan. The small circles with 1s error represent the 14C ages against varve ages. For the oldest eight points (>38,000 years, filled circles), we assumed a constant sedimentation during the Glacial period. The green symbols correspond to the tree-ring calibration (2, 15), and the large red symbols represent calibration by combined 14C and U-Th dating of corals from Papua New Guinea (squares) (8), Mururoa (circles), and Barbados (triangles) (7). The line indicates that radiocarbon age equals calibrated age.

In this case lake varves (blue) on one axis, C14 age calculations on the other axis (and also showing tree rings (green) on the first axis with C14 age calculations on the other as above).

Obviously counting layers and counting tree rings is not using C14 to find the dates of the layers and rings, this is not circular reasoning at all.

Message 5 of the GD: The consensus could easily be rainfall related and out by approximately a factor of twelve ...

Really? Occurring in exactly the same pattern in three different locations on earth: Sierra Nevada mountains, Ireland and Germany ... ? Remember there are three dendrochronologies that agree ring by ring over a period of 8,000 years with an error of only 37 rings\years -- an error rate of less than 0.5%.

Message 5 of the GD: ... Lake Suigetsu is doubtful as discussed in the other thread, as follows:

1) Lake Suigetsu is so low lying and so near the coast that very high tides could cause mass Diatom die-offs creating diatom layers that are more frequent than annual. This is not fairytale what-ifs but a highly probable scenario given the lake's proximity to the sea. Diatoms form layers on the surface of the lake, as the salt water table rises this would kill off the lower freshwater diatoms. Someone speculated that the salt water would not rise high enough to kill off the lowest diatoms however this was mere speculation. No figures were actually presented (depth of lake/depth of diatom layer/depth of saltwater).

2) Lake Suigetsu is fed by the Hasu river. This is a small river with a small catchment area. Sediment flows into Lake Suigetsu would be affected by every large rainfall and not necessarily be perfectly seasonal.

Again, it does not matter how many diatom mass deaths occur in a year or how much the river flow changes, as this does not affect the layer formation. There could be 50 mass deaths in one summer and there would be one diatom layer for the year. There could be 50 storms and it wouldn't affect the winter layer formed by clay sediment.

This is because the diatoms settle fast -- within a day of death -- while the clay settles slowly taking months to form a layer only when there are no further diatom deaths: only the winter months provide the time necessary to form a clay layer.

We also see from this graph:

quote:
Message 21 of Age Correlations and An Old Earth, Version 2 No 1: Here is some more information from the Lake -- the correlation of both the varve ages and the 14C ages with the actual depth in the sediment.

A 40,000-YEAR VARVE CHRONOLOGY FROM LAKE SUIGETSU, JAPAN: EXTENSION OF THE 14C CALIBRATION CURVE

quote:
RESULTS

Figure 1 shows the varve and 14C chronologies as a function of depth of the SG core. Until now, the varve numbers have been counted in the 10.42-30.45 m deep section. The Lake Suigetsu floating varve chronology consists of 29,100 varves. As shown in Figure 1 the sedimentation or annual varve thickness is relatively uniform (typically 1.2 mm yr-1 during the Holocene and 0.62 mm yr-1 during the Glacial). The age below 30.45 m depth is obtained by assuming a constant sedimentation in the Glacial (0.62 mm yr-1). The 14C ages at 10.42, 30.45 and 35 m depth are ca. 7800, 35,000 and 42,000 BP, respectively.


Note the correlation between C-14 and depth with C-14 and varve count. See how at about 11,000 years ago ("BP" means "before present" with "present" defined as 1950 CE), both show a matching change in slope of the curves with depth.


At about 11,000 years ago there was a change in the deposition rate in the lake, and this did not affect the counting of the layers.

Enjoy

Edited by RAZD, : added comments


we are limited in our ability to understand
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Rebel American Zen Deist
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This message is a reply to:
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Replies to this message:
 Message 29 by RAZD, posted 11-13-2013 6:39 PM RAZD has responded

  
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 10 of 305 (710880)
11-12-2013 8:26 AM
Reply to: Message 9 by Percy
11-12-2013 7:50 AM


what?
The graph *does* indicate about 1.2 varve layers per year on average.

What? Source please.


This message is a reply to:
 Message 9 by Percy, posted 11-12-2013 7:50 AM Percy has acknowledged this reply

  
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 29 of 305 (710993)
11-13-2013 6:39 PM
Reply to: Message 8 by RAZD
11-12-2013 7:35 AM


Re: Great Debate Message 6 and evidence correlations
In Message 6 of the GD Coyote lets an important issue slide, imho:

Your main objection to radiocarbon dating, that is, tree-rings, is out the window, gone, and radiocarbon dating still produces ages far in excess of what it would take to falsify your beliefs.

This is virtually accepting mindspawns objection as reason to stop using\considering this information as valid objective evidence of age. Certainly it allows mindspawn to think he can just throw out some objection to any form of evidence and Coyote will roll over on it.

The issue is correlation -- why do the tree rings correlate with the C14 ages if either are wrong. You have 3 separate tree ring chronologies that correlate with each other, including one chronology with living trees over 5,000 years old, and these correlations show the validity of the dating method with an error of less than 0.5% between them.

They correlate on climate data contained in the width of the rings for over 8,000 years of record. Extra rings would not have this correlation.

These chronologies also correlate with the C14 ages with a difference of ~10%, with a lack of scatter in the C14 data: this is not a "best fit" mathematical correlation but a raw data correlation that shows a strong consistency of C14 data along a curve. The lack of scatter in the data shows how strong the correlation is.

In addition to the strong correlation of the tree ring data and the C14 data, there is an additional correlation of the C14 data along that curve with the 11 year solar cycle that causes distinct patterns of peak and valley cosmic ray production that is the cause of C14 in the atmosphere.

These correlations are not explained by handwaving comments about extra tree rings and the false claim of circular reasoning.

Enjoy.


we are limited in our ability to understand
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Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
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This message is a reply to:
 Message 8 by RAZD, posted 11-12-2013 7:35 AM RAZD has responded

Replies to this message:
 Message 30 by RAZD, posted 11-13-2013 6:48 PM RAZD has responded

  
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 30 of 305 (710994)
11-13-2013 6:48 PM
Reply to: Message 29 by RAZD
11-13-2013 6:39 PM


Re: Great Debate Message 7 and Gish Gallop, accuracy v precision
In Message 7 mindspawn -- perhaps thinking he has succeeded in discrediting tree rings moves on:

All you used to make your point is one graph with a few labels on it.
I challenged the Suigetsu dates on that graph, if you give me more information, I will challenge all the other dates on that graph.

for example the Bahamas Speleothem data...

In other words, he will continue to challenge every bit of evidence on it's own standing, something creationists are fairly adept at (it is easy to make up challenges), amounting to a Gish Gallop of challenges if Coyote is not careful.

The failure here is ignoring the issue of correlations, something creationists have to date been unable to challenge.

Its entirely possible that the consensus in radiocarbon dating is obtained merely through misunderstanding rainfall sensitive data as representing annual/seasonal data.

The tree ring annual and climate data correlate with known history for over 2,000 years without any such misrepresentation due to rainfall. For over 4,000 years you have 3 Bristlecone Pines on different mountains in the Sierra Nevada that correlate on climate, and two Oak chronologies, one in Ireland, one in Germany, that correlate with each other on climate and also with the three Bristlecone Pines. In addition the "year with no summer" is correctly identified in the tree ring data -- it shows up as a winter portion of the ring that is twice as wide as the normal winter portions. This alone is sufficient to show his claim of "misunderstanding rainfall sensitive data" is superfluous hand waving.

Another issue here is confusing accuracy, precision and calibration:

Accuracy means your ability to hit the target. If we take a bow and arrow and shoot 50 times at a target, and all the arrows average out to a bull's eye, then the average result is accurate, even though there may be significant error in any one shot and there may not be a single bull's eye in the whole group. There could be a fairly large degree of scatter in the data and still have an accurate average result.

Precision means the ability to replicate exactly the same results. With our bow and arrow example we now have 50 arrow all clustered very close together, but they may or may not be located near the bull's eye. There is very little scatter in this case

Calibration means taking a precise system and determining what needs to be done to correct the precise result to be an accurate result.

Notice that the age of the tree ring chronologies extends back to 12,460 years before the present day (2010), thus we can certainly compare the tree rings to the 14C data for precision and accuracy

To do this we do not need to actually calculate the 14C age but just measure the ratio of 14C to 12C in the tree rings.

Precision:

The measurement of the 14C to 12C ratio is highly precise, with different labs repeatedly getting the same results from samples from the same tree ring.

The error of less than 0.5% between the three chronologies shows a high degree of precision (99.5%), as each one produces the same results. There is also a high degree of precision in the 14C to 12C ratio data compared to the three dendrochonologies, as is demonstrated in the curves showing very little scatter in the data along the correlation curve.

  • each ring formed captures the 14C/12C ratio of the atmosphere for the year the ring was formed.
  • trees anywhere on earth, in Germany, in Ireland and or high in the Sierra Nevadas, all have the same atmospheric 14C/12C ratio to absorb into the growth rings in the same year.

    :. tree rings for the same age from each of the chronologies should have the same proportion of 14C/12C: not surprisingly, they do.

Accuracy (1)

When we look at the correlation graph we see that the C14 data is consistently off the actual age by ~10% ... ie it is 90% accurate.

How can we check the accuracy of the tree rings by other data?

Because 14C is produced in the atmosphere by cosmic rays, and the incidence of cosmic rays from the sun varies on an 11 year (sunspot) cycle, we can look for this pattern in the 14C/12C data in the tree rings. This pattern consistently shows up in the data from each of the three dendrochronologies.

Now when we compare those estimated ages with the known ages for the tree ring samples we can see that the 14C/12C data, while being highly precise, is not quite accurate, being off the bull's eye by about 10% for actual age ... but that it accurately picks up the 11 year cycle:

Thus we see that the correlation between the tree ring count, the climate\season pattern and the 14C/12C proportions within the tree rings for the three different chronologies, even without using 14C to measure the age, shows the system is 90% accurate with a high degree of precision.

It is because of the high precision of the system that the accuracy of the system can be improved by calibration.

Enjoy.

Edited by RAZD, : ...

Edited by RAZD, : accuracy and precision

Edited by RAZD, : subT

Edited by RAZD, : wording

Edited by RAZD, : egls


we are limited in our ability to understand
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This message is a reply to:
 Message 29 by RAZD, posted 11-13-2013 6:39 PM RAZD has responded

Replies to this message:
 Message 31 by RAZD, posted 11-13-2013 8:13 PM RAZD has responded

  
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 31 of 305 (710997)
11-13-2013 8:13 PM
Reply to: Message 30 by RAZD
11-13-2013 6:48 PM


Re: Great Debate Message 8 ... perhaps time to educate
In Message 8 of the GD coyote says

You just don't understand radiocarbon dating enough to get the point I'm making. This is becoming frustrating!
So we are no longer talking about tree-rings, varves, corals, or any of those other methods of establishing a calibration curve.

We are talking about "conventional" radiocarbon ages. These are the measured age as corrected for isotopic fractionation. No calibration is done at all.

This is an opportunity to show how radiocarbon dating works, rather than vent frustration.

To use the measured 14C/12C ratio in a sample to estimate the age of the sample we use the measured half-life of 14C and the exponential curve of decay for that half-life:


Graph of actual 14C content versus actual time intervals from time "X"

This gives us an estimated age of the sample based on the proportion of 14C/12C as compared to the proportion of 14C/12C in the atmosphere in 1950 (chosen as an arbitrary date for consistency in reporting results, hence all 14C ages are reported in "years BP" where BP means 1950).

This is a purely mathematical conversion from the 14C/12C ratio in a sample. This calculation is not affected by "misunderstanding rainfall sensitive data" because it is entirely independent of climate and rainfall -- it depends solely on the 14C/12C ratio in a sample.

Thus any one specific 14C/12C ratio in a sample will produce precisely the same estimated age of the sample.

It is when we compare those estimated ages with the known ages for the tree ring samples (or other known sources) that we can see that the 14C/12C data, while being highly precise, is only ~90% accurate (with the radiocarbon age estimate being younger than the tree ring age).

What mindspawn throws out as objections to the system should be visible as increased scatter in the data -- less precision rather than less accuracy -- and that scatter and loss of precision just is not there, regardless of the accuracy.

Enjoy.

Edited by RAZD, : clarity


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This message is a reply to:
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RAZD
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Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
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Message 32 of 305 (710998)
11-13-2013 8:50 PM
Reply to: Message 26 by NoNukes
11-13-2013 3:02 PM


back to correlations again
... varves are expected by spring tides, and tree rings counts are affected by rain. So, I wonder how he explains the extremely tight correspondence between the two. The correspondence is actually much better than uncalibrated C-14 data and either of the aforementioned non-radiometric indications. That's the kind of info he should be slammed with, because the conformance pretty much proves that his objection is absolutely wrong.

Exactly -- it is the correlations between the rings and the varves and the respective 14C/12C ratios over their period of overlap that show a consistent pattern.

Enjoy


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RAZD
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(1)
Message 34 of 305 (711015)
11-14-2013 8:51 AM
Reply to: Message 31 by RAZD
11-13-2013 8:13 PM


Re: Great Debate Message 9 and correlations again
Mindspawn admits to misunderstanding ... a beginning?

In Message 9 of the GD mindspawn says

You are correct, I don't understand what you are talking about. I am not focusing on the calibration curve, my arguments have been clearly focused on the dates at those 7 locations. 4 locations are precipitation sensitive more than seasonally sensitive, 3 of those locations use uranium-thorium dating.

mindspawn should be asked how the data would correlate into such a precise curve with very little scatter in the data if it were "precipitation sensitive" -- starting with the tree rings from three separate locations and ecosystems.

Why are the combined results precisely the same with 99.5% accuracy for the Irish Oak chronology, the German Oak chronology and the Bristlecone Pine cronology -- can mindspawn show that each area had precisely the same pattern of precipitation?

On the surface of it your argument appears sound, but as you delve into each location, the assumption of annual layers appears doubtful because the layers at 4 of those 7 locations would more likely reflect strong precipitation than actual seasonal layers. ie the layers are formed from each and every significant rainfall, and are not formed annually.

Then why do they correlate at all? Why is there a precise correlation if there is such a sensitivity?

Rather obviously, to me, mindspawn does not really understand how dendrochronology works and so he is clutching to a straw argument.

http://web.utk.edu/~grissino/principles.htm

quote:
tree ring

A layer of wood cells produced by a tree or shrub in one year, usually consisting of thin-walled cells formed early in the growing season (called earlywood) and thicker-walled cells produced later in the growing season (called latewood). The beginning of earlywood formation and the end of the latewood formation form one annual ring, which usually extends around the entire circumference of the tree.

tree-ring chronology

A series of measured tree-ring properties, such as tree-ring width or maximum latewood density, that has been converted to dimensionless indices through the process of standardization. A tree-ring chronology therefore represents departures of growth for any one year compared to average growth. For example, an index of 0.75 (or 75) for a given year indicates growth below normal (indicated by 1.00, or 100).

The Principle of Crossdating

This principle states that matching patterns in ring widths or other ring characteristics (such as ring density patterns) among several tree-ring series allow the identification of the exact year in which each tree ring was formed. For example, one can date the construction of a building, such as a barn or Indian pueblo, by matching the tree-ring patterns of wood taken from the buildings with tree-ring patterns from living trees. Crossdating is considered the fundamental principle of dendrochronology - without the precision given by crossdating, the dating of tree rings would be nothing more than simple ring counting!

The Principle of Replication

This principle states that the environmental signal being investigated can be maximized, and the amount of "noise" minimized, by sampling more than one stem radius per tree, and more than one tree per site. Obtaining more than one increment core per tree reduces the amount of "intra-tree variability", in other words, the amount of non-desirable environmental signal peculiar to only tree. Obtaining numerous trees from one site, and perhaps several sites in a region, ensures that the amount of "noise" (environmental factors not being studied, such as air pollution) is minimized.


Cross-dating and replication are used to eliminate the effects mindspawn is fixated on.

The tree ring chronologies also match with historical data for the "year without a summer" -- something that could not have occurred if the dendrochronologists had not been able to correctly identify annual rings ...

google site:http:http://web.utk.edu/~grissino/ "year without a summer" and you will get several results, of which this is one:

web.utk.edu/~grissino/downloads/van-west-grissino-mayer-2005.pdf

quote:
... A minor dry spell between A.D. 1809 and 1829 was broken by an exceptional three-year period between A.D. 1815 and 1817, during which each year expressed either an extreme wet or cool value. The year A.D. 1815, of course, is the year of the extraordinarily large eruption of Mount Tambora in Indonesia, and there were also several documented eruptions of lesser force from the western Pacific during the A.D. 1812B1817 period, including eruptions in Indonesia, the Philippines, and the Ryuku Islands (Salzer 2000a:115). It was so markedly cold in Europe and eastern North America in A.D. 1816 that it has been dubbed as the Ayear without summer@ (Harrington 1992). In addition to being wetter than normal, most of the first half of the nineteenth century (ca. A.D. 1809B1856) was considerably cooler than normal. Although the wetness continued through A.D. 1891, annual temperatures were moderate throughout much of the second half of the century. Of the four frost rings recorded in the SFPB chronology ( A.D. 1810, 1828, 1882, and 1884), only the first two correlate with volcanically active periods known to have lowered temperatures (Salzer 2000a:95, 115). The century ended with a 13-year dry-warm drought of modest proportions (Interval 192, spanning A.D. 1892B1904).

In spite of that wide variation in climate, from drought to extreme wet, the dendrochronology was both precise and accurate in identifying the "year with no summer" ... perhaps the dendrochronolgists DO know what they are doing?

His comments re Lake Suigetsu are also falsified by how the layers form, and they are not sensitive in the way he suggests. The clay layer only forms when there are months of no diatom deaths -- winter months -- as the clay settles so slowly that it cannot form a layer between summer blooms/busts as mindspawn conjectures.

The real problem for him, though, is to show that the correlations occur due to weather rather than annual formations in four locations around the globe: his weather patterns would have to be precisely the same in those locations to produce the same precise annual data.

This means that on the graph the carbon dates should be re-calibrated according to number of significant precipitations per year, and the actual dates should also be adjusted to reflect these multiple layers per year (of varves/tree rings/ice layers).

Curiously, dendrochronologists already check for multiple layers and have methods to identify them. As noted above they are accurately able to sort a wide variety of climate differences into their appropriate age chronologies. This is why the three dendrochronologies agree within 99.5% at over 8,000 years.

Enjoy


we are limited in our ability to understand
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Rebel American Zen Deist
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This message is a reply to:
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RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 35 of 305 (711016)
11-14-2013 8:53 AM
Reply to: Message 34 by RAZD
11-14-2013 8:51 AM


Re: Great Debate Message 10 and basics on radiometric systems
In Message 10 midspawn states

Regarding the last 3 of the 7 locations referred to on your graph, it appears the Carico Basin and Papua New Guinea dates are established through comparing Uranium-Thorium dating with Radiocarbon dating. I am still looking into how they originally calibrated Uranium-Thorium dating , if they calibrated this according to carbon dating, this ruins the claimed consilience, ...

They don't. All radiometric methods are "originally calibrated" by their specific decay rates. The shorter the half-life involved the more sensitive the system is to recent times.

http://www.asa3.org/ASA/resources/Wiens.html
Radiometric Dating
A Christian Perspective
Dr. Roger C. Wiens

quote:
There are other ways to date some geologically young samples. Besides the cosmogenic radionuclides discussed above, there is one other class of short-lived radionuclides on Earth. These are ones produced by decay of the long-lived radionuclides given in the upper part of Table 1. ...

Like carbon-14, the shorter-lived uranium-series isotopes are constantly being replenished, in this case, by decaying uranium-238 supplied to the Earth during its original creation. Following the example of carbon-14, you may guess that one way to use these isotopes for dating is to remove them from their source of replenishment. This starts the dating clock. In carbon-14 this happens when a living thing (like a tree) dies and no longer takes in carbon-14-laden CO2. For the shorter-lived uranium-series radionuclides, there needs to be a physical removal from uranium. The chemistry of uranium and thorium are such that they are in fact easily removed from each other. Uranium tends to stay dissolved in water, but thorium is insoluble in water. So a number of applications of the thorium-230 method are based on this chemical partition between uranium and thorium.

On the other hand, calcium carbonates produced biologically (such as in corals, shells, teeth, and bones) take in small amounts of uranium, but essentially no thorium (because of its much lower concentrations in the water). This allows the dating of these materials by their lack of thorium. A brand-new coral reef will have essentially no thorium-230. As it ages, some of its uranium decays to thorium-230. While the thorium-230 itself is radioactive, this can be corrected for. The equations are more complex than for the simple systems described earlier, but the uranium-234 / thorium-230 method has been used to date corals now for several decades. Comparison of uranium-234 ages with ages obtained by counting annual growth bands of corals proves that the technique is highly accurate when properly used (Edwards et al., Earth Planet. Sci. Lett. 90, 371, 1988).


Dr Wiens is a good source of information regarding radiometric dating methods.

... In this way they can establish a calibration curve for uranium-thorium dating which they can use for periods earlier than carbon dating can function. ...

This comment shows he does not appear to understand the paper: 14C dating works on samples that formed last year ...

Enjoy.


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This message is a reply to:
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Replies to this message:
 Message 38 by RAZD, posted 11-14-2013 9:38 AM RAZD has responded

  
RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


(3)
Message 38 of 305 (711021)
11-14-2013 9:38 AM
Reply to: Message 35 by RAZD
11-14-2013 8:53 AM


Re: Great Debate Message 11 and misunderstanding
In Message 11 midspawn states

I've been thinking about what you have been saying, and realize where the misunderstanding could have come in. I think your graph distracted me because that is the only supporting evidence that you have posted and your graph was referring to various forms of corroboration, and comparing these to calibrated radiocarbon dates (dates that had been adjusted for variation of the magnetic field and calibrated according to other forms of dating).

No. The dates calculated from the 14C/12C ratio are based on the exponential decay curve for 14C, there is no adjustment "for variation of the magnetic field" -- another red herring.

Annual counts on one axis, raw 14C/12C ratio dates on the other. Simple.

quote:
Age Correlations and An Old Earth, Version 2 No 1, Message 4

... The "carbon-14 age" of a sample is really a measurement of the quantity of carbon-14 in the sample compared to the total carbon in the sample. This quantity measurement is then transformed by a mathematical formula based on radioactive decay into a theoretical "age," but this "age" is really just a mathematical scale for displaying the actual amount of carbon-14 in the sample. ... two samples of the same age - that lived in the same atmospheric environment and absorbed the then existing levels of atmospheric carbon-12, carbon-13 and carbon-14 (the three common isotopes) - will have the same levels of carbon-14 in the samples today. ... Thus, when sample {A} is dated to {X} years by dendrochronology and it has level {Y} carbon-14 content, and when sample {B} is also dated to {X} years by dendrochronology and it has level {Y} carbon-14 content, the carbon-14 content validates the age - because, growing in the same environment, they could not be the same age and NOT have the same carbon-14 content.

Carbon-14 is a radioactive isotope of carbon.

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

quote:
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.

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

quote:
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%.

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

quote:
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.

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)

quote:

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).

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.

Age Correlations and An Old Earth, Version 2 No 1, Message 5

... The age calculation is based on the exponential decay curve for a radioactive element with a half-life of 5730 years:

http://science.howstuffworks.com/carbon-14.htm/printable (2)

t = {ln (Nf/No)/ln (1/2)} x t1/2

where t is the "C-14 age", ln is the natural logarithm, Nf/No is the percent of carbon-14 in the sample compared to the amount in living tissue, and t1/2 is the half-life of carbon-14.
t = {ln (Nf/No)/-0.69315} x 5730 = -8267 x ln (Nf/No)

Where No is the original level of the C-14 isotope in the sample (when it was alive and growing and absorbing atmospheric C-14), and Nf is the amount remaining. The value for No today is ~0.00000000010% of total organic carbon and Nf is smaller depending on how much time has passed.

Exponential curves look like this:

We can calculate (Nf/No) ratios for a number of decay ages and use those with the horizontal time frames to show what the approximate ratios would have been (we could refine those by multiplying by the ratio between the data point elevations and the 1:1 correlation line if we want to get more accurate numbers):

(Nf/No) = e^(t/-8267)

Age (yrs BP) Ratio (Nf/No)
5,730 0.5000 (= 1 half life)
8,000 0.3799
8,500 0.3576
8,830 0.3436
9,000 0.3366
9,500 0.3169
10,000 0.2983
10,500 0.2808
11,000 0.2643
11,460 0.2500 (= 2 half lives)
11,500 0.2488
12,000 0.2342
12,326 0.2251
12,500 0.2204
13,000 0.2075
13,500 0.1953
14,000 0.1839
14,500 0.1731
15,000 0.1629
15,500 0.1534
16,000 0.1444
16,500 0.1359
17,000 0.1279
17,190 0.1250 (= 3 half lives)

So you can take the raw data 14C/12C ratio and compare it to the exponential decay curve for 14C (half-life 5730 years) to determine the mathematical 14C age of the sample.

No correction or calibration.

Then, when you compare that to annual layer data (tree rings or lake varves) you see the difference between this mathematical age and the actual age, where the difference is caused by the variation in the levels of 14C in the environment at the time the sample formed (tree ring or leaf, whatever):

quote:
Age Correlations and An Old Earth, Version 2 No 1, Message 5

In the case of the Lake Suigetsu Lake Varves they present a calibration curve as well, and we can use this to represent the Carbon-14 environment in the same way we did for the tree-rings - as an indicator of what the levels of Carbon-14 were when the organic samples were alive and growing.

http://www.sciencemag.org/cgi/content/abstract/279/5354/1187 (3)

quote:

Fig. 1. (A) Radiocarbon calibration up to 45,000 yr B.P. reconstructed from annually laminated sediments of Lake Suigetsu, Japan. The small circles with 1s error represent the 14C ages against varve ages. For the oldest eight points (>38,000 years, filled circles), we assumed a constant sedimentation during the Glacial period. The green symbols correspond to the tree-ring calibration (2, 15), and the large red symbols represent calibration by combined 14C and U-Th dating of corals from Papua New Guinea (squares) (8), Mururoa (circles), and Barbados (triangles) (7). The line indicates that radiocarbon age equals calibrated age.

We are only concerned here with the open blue circles and their match to the green tree-ring data. We can note in passing, however, that the other data (red open squares and triangles) span from the dendrochronology to the lake chronology, and operate as a validating correlation link between them.


Note the lack of scatter in the graph, showing that the data is highly precise.

Enjoy.


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
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This message is a reply to:
 Message 35 by RAZD, posted 11-14-2013 8:53 AM RAZD has responded

Replies to this message:
 Message 39 by Diomedes, posted 11-14-2013 10:41 AM RAZD has acknowledged this reply
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RAZD
Member
Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


Message 41 of 305 (711053)
11-14-2013 12:37 PM
Reply to: Message 40 by JonF
11-14-2013 10:52 AM


Re: Spring tides
Has any ever told this buffoon that there are two spring tides per month rather than just one?

Percy did once.

Actually there are ~25 per year ...

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

quote:
... The time between two full moons (a Lunar month) is about 29.53 days[1] (29 days, 12 hours, 44 minutes) on average ...

That's 2x365.24/29.53 = 24.74 per year ...

... and the calibration curve would be nearly vertical ...

... because the horizontal axis would be compressed while the mathematical calculation of age from the 14C/12C ratios in the samples would be unaffected.

As this is not the case it is patently obvious that tides are not a factor, which we knew anyway.

Enjoy


This message is a reply to:
 Message 40 by JonF, posted 11-14-2013 10:52 AM JonF has not yet responded

  
RAZD
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Posts: 19981
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 4.0


(1)
Message 44 of 305 (711075)
11-14-2013 10:02 PM
Reply to: Message 38 by RAZD
11-14-2013 9:38 AM


Re: Great Debate Message 13 and Message 14
In Message 13 midspawn states

http://en.wikipedia.org/wiki/Carbon-14
"Production rates vary because of changes to the cosmic ray flux incident, such as supernovae, and due to variations in the Earth's magnetic field. The latter can create significant variations in carbon-14 production rates, although the changes of the carbon cycle can make these effects difficult to tease out"

"The natural atmospheric yield of carbon-14 has been estimated to be about 22 000 atoms 14C per meter square of the surface of the earth per second, resulting in the global production rate of about 1 PBq/a.[11] Another estimate of the average production rate[12] gives a value of 20 500 atoms m−2s−1. Occasional spikes are possible; for example, there is evidence for an unusual 10-fold increase of the production rate in AD 774–775.[13]"

We have known for decades that the amount of 14C in the atmosphere varies, and we've also known that one of the causes of this variation is the 11 year sunspot cycle in the production of cosmic rays.

We have also known that the predominant area where 14C is produced is in the upper layers of the troposphere and the stratosphere by thermal neutrons absorbed by nitrogen atoms.

http://en.wikipedia.org/wiki/Carbon-14

quote:
The highest rate of carbon-14 production takes place at altitudes of 9 to 15 km (30,000 to 50,000 ft) and at high geomagnetic latitudes.

ie -- over the poles, due to the interaction of the cosmic rays with the magnetic field that shields most of the earth from them.

mindspawn quotes wiki (see above) and then claims

A ten-fold increase was recorded in AD 774-775. Spikes are possible. The strength of the magnetic field causes significant variation. It appears that the conventional carbon dates require significant calibration to be an accurate reflection of true dates. The accuracy of carbon dating is entirely dependent on calibration with known dates.

What we are seeing is a confusion of the production rate with the total reservoir of 14C in the atmosphere. Let's look at wiki a little further:

quote:
Dispersion in the environment

After production in the upper atmosphere, the carbon-14 atoms react rapidly to form mostly (about 93%) 14CO (carbon monoxide), which subsequently oxidizes at a slower rate to form 14CO2, radioactive carbon dioxide. The gas mixes rapidly and becomes evenly distributed throughout the atmosphere (the mixing timescale in the order of weeks). Carbon dioxide also dissolves in water and thus permeates the oceans, but at a slower rate.[10] The atmospheric half-life for removal of 14CO2 has been estimated to be roughly 12 to 16 years in the northern hemisphere. The transfer between the ocean shallow layer and the large reservoir of bicarbonates in the ocean depths occurs at a limited rate.[15]


Newly produced 14C gets transformed into 14CO2 and is dispersed world-wide in a matter or weeks, but it takes 12 to 16 years for half of that newly produced 14CO2 to be removed from the atmosphere -- ie taken up by plants or the ocean.

As an analogy consider a large canister of water, new water is introduced from a variable source, with spikes up to 10 times average rates of flow, out flow is at the bottom and is fairly steady, but varies with the depth of the water. When inflow exceeds outflow the level in the canister rises and outflow increases slightly, and when the outflow exceeds the inflow the level lowers and outflow decreases slightly. The larger the reservoir in the canister the smaller the effect of inflow spikes on the overall volume.

When we see that "atmospheric half-life for removal of 14CO2 has been estimated to be roughly 12 to 16 years in the northern hemisphere" we can see that this essentially means that the total reservoir is large in comparison to the production as the change to the total volume of 14C would be more related to a 14 year running average of production.

Thus the overall effects of variation in the production of 14C in the atmosphere are smoothed out by the total reservoir of 14C in the atmosphere.

Not surprisingly this is reflected in the actual graphs of 14C against known age samples.

A ten-fold increase was recorded in AD 774-775. Spikes are possible. The strength of the magnetic field causes significant variation. It appears that the conventional carbon dates require significant calibration to be an accurate reflection of true dates. The accuracy of carbon dating is entirely dependent on calibration with known dates.

Nope. Input variation does not equal total reservoir variation, just a fraction of it. Curiously 14C measurements are dependent on total reservoir levels, not on production.

In Message 14 coyote replies

And your objection that cosmic rays/magnetic field can cause radiocarbon dates to vary wildly is unfounded. That is what the calibration curve does--it permits correction of the conventional radiocarbon ages for the effects of cosmic rays and the changing magnetic field. In other words, the variations in C14 levels in the atmosphere are accounted for! There goes your objection.

Raw 14C results on the "y" axis, actual age on the "x" axis. This IS the calibration that shows the total reservoir variation over time.

Raw 14C dates have a series of spikes and jags, yes, due to variations in the total reservoir levels of 14C, yes, but the overall pattern is precise (there is a precise, repeatable, relation between 14C date and actual date) and a 90% overall accuracy.

Enjoy

Edited by RAZD, : added

Edited by RAZD, : clarity


we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.


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