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Author Topic:   Radioactive carbon dating
JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 196 of 221 (541287)
01-02-2010 8:21 AM
Reply to: Message 195 by sailorstide
01-02-2010 7:59 AM


Re: The Missing Link Returns
Radioactive carbon dating and its accuracy is not based on any claim on constancy of solar flare activity.

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Percy
Member
Posts: 22392
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 197 of 221 (541293)
01-02-2010 9:18 AM
Reply to: Message 195 by sailorstide
01-02-2010 7:59 AM


Re: The Missing Link Returns
Hi Sailorstide,
Your concern is that the variability of 14C production makes radiocarbon dating unreliable, and this is a legitimate concern. There are some natural processes that are sufficiently constant and consistent that they can be used for dating, and some that cannot. For example, the rate of deposition of geological layers as well as the possibility of negative deposition (e.g., through erosion) is so variable that their thickness cannot be used as a reliable dating measure.
So the general question you're raising is whether the rate at which 14C is added to our atmosphere is sufficiently consistent to provide a reliable dating measure, and you're specifically singling out solar flares as a potential source of variability.
The huge solar flare of 1956 was mentioned in a similar thread (see Message 59 in thread Request for Carbon-14 Dating explanation), and it is described this way in Solar Modulation of Cosmic Ray Intensity and Solar Flare Events Inferred from 14C Contents in Dated Tree Rings:
According to Lingenfelter and Ramaty (1970), the number of 14C nuclei produced by the 1956 solar flare is equivalent to the one-year production by cosmic ray particles.
The half life of 14C is approximately 5730 years. That means that however much 14C is on the Earth right now, only half it will still be around in 5730 years. Only 1/4 of it will still be around in 11,460 years. It takes more than 50,000 years for so much of it to decay that it's nearly indetectable.
In other words, it takes a long time for 14C to disappear once it's been created. It's as if you have a large swimming pool into which you add a single drop of a special treatment chemical every day, and it takes 50,000 years for a drop of the chemical to degrade. The drop of chemical you add today is added to the drop you added yesterday, and the drop you added the day before, and the day before that, and so forth back 50,000 years. The drop you add today is a minuscule amount compared to what is already in the pool.
So if on one day out of every 11 years or so (the period length of our sun's solar flare cycle) you add 365 drops instead of just one drop, those 365 drops are still just a teensy, teensy portion of the number of drops already in the pool. No one would ever notice. You'd have to add gallons and gallons of special chemical for anyone to notice without doing a detailed chemical analysis.
The same is true of the amount of 14C already resident on earth. There's 50,000 year's worth of 14C already here. If during a solar flare an entire year's worth of 14C is added on a single day it would barely be noticeable. And as that technical paper I referenced above describes, it really is only just barely detectable.
So if there had never been any solar flare activity before 50 years ago (50 years ago is what you mentioned) and the amount of 14C on earth were reduced by the amount of all the solar flares that we assume would normally occur, it would have a barely measurable effect on the dates yielded by radiocarbon dating. Perhaps something measured as 10,000 years old might really be only 9,900 years old.
And if solar flare activity in the past were actually much greater than it is today then it would affect radiocarbon dating in the wrong direction for young earth arguments. If there had been huge amounts of ancient solar flare activity of which we were completely unaware then objects dated to be 10,000 years old would actually be much, much older.
Dates yielded by the radiocarbon dating method strongly agree with dates yielded by other methods, such as tree rings, ice cores, and lake sedimentary layers (usually called varves). This agreement would be impossible if radiocarbon dating was an invalid method.
--Percy
Edited by Percy, : Grammar.

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dennis780
Member (Idle past 4776 days)
Posts: 288
From: Alberta
Joined: 05-11-2010


Message 198 of 221 (559885)
05-12-2010 12:55 AM
Reply to: Message 8 by Chiroptera
05-07-2006 4:41 PM


dating game
"Carbon dating is not used to date fossils." ANYMORE.
This is very key.
Carbon dating was the first and only method of dating for 10 years.
The "new" parent-daughter dating methods run into the same problems as carbon dating though they fix the radioactive halflife issue.
You cannot date any fossil properly without knowing how much of the parent substance there was to begin with. Any fossil rich in the parent substance (be it argon, or potassium, etc.) would give inaccurate data. You can't know how much time has passed if you don't know how much sand was in the hourglass to begin with. This is pretty basic.
Levels of all radioactive parent substances differ worldwide, and even in specific areas at different times change. We do our best to measure changes, then extrapolate this data backwards, but any catastrophic change in conditions will influence levels greatly, and again, give us a false date.
Taking a closer look at the fossils themselves, instead of relying on radioactive dating itself can give some insight into the actual dates. Scientists have found fossilized lobster shells from lobsters that are STILL ALIVE. Carbon dating claimed them to be over a thousand years old. But the lobster was still ALIVE.
This shows two things. Firstly, that carbon dating is not an exact science, and since the other methods of radiocarbon dating use the same process, it is possible to question their dates as well. The second, that fossilization can occur rapidly. This is also evident with fossils of mammoth graveyards, Mammoths in the middle of giving birth and in the middle of battle. Lizards with their tongue sticking out, etc. These are all examples of fast fossilization.
Lets finish with this question. How long does it take to make a fossil? Does a long time seem reasonable? Would the structure of the animal remain intact for millions of years? Just askin.
Dennis.

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Replies to this message:
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Taq
Member
Posts: 9973
Joined: 03-06-2009
Member Rating: 5.6


Message 199 of 221 (559978)
05-12-2010 11:00 AM
Reply to: Message 198 by dennis780
05-12-2010 12:55 AM


Re: dating game
You cannot date any fossil properly without knowing how much of the parent substance there was to begin with.
First of all, the actual fossil is not dated. It is the surrounding rock that is dated.
Secondly, it is the ratio of parent to daughter isotope that is used. For example, if you start with 1 g of uranium after 1 halflife you will have 0.5 g of uranium and 0.5 g of lead. If you start with 5 g of uranium then after one half life you will have 2.5 g of uranium and 2.5 g of lead. It is the RATIO that is important.
You can't know how much time has passed if you don't know how much sand was in the hourglass to begin with.
Last I checked an hourglass is a closed system so the amount of sand in the hourglass is how much you started with.
Scientists have found fossilized lobster shells from lobsters that are STILL ALIVE. Carbon dating claimed them to be over a thousand years old. But the lobster was still ALIVE.
Lobsters get their carbon from marine sources which are richer in old carbon. This is what causes the older date. Scientists know all about this effect. This in no way negates the accuracy of carbon dating for terrestrial samples that derived their carbon from atmospheric sources.
The second, that fossilization can occur rapidly.
You are confusing perminerlization with burial. The process of replacing organic material with minerals from the surrounding rock is a slow process. However, no one is claiming that animals and plants can not be buried quickly.

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 200 of 221 (560010)
05-12-2010 2:19 PM
Reply to: Message 198 by dennis780
05-12-2010 12:55 AM


Re: dating game
Carbon dating was the first and only method of dating for 10 years.
Way off. Rutherford dated the first rock in 1905, and the field was developed continuously from then. Libby invented carbon dating in 1949.
You cannot date any fossil properly without knowing how much of the parent substance there was to begin with. Any fossil rich in the parent substance (be it argon, or potassium, etc.) would give inaccurate data. You can't know how much time has passed if you don't know how much sand was in the hourglass to begin with. This is pretty basic.
Sorry, wrong. In fact, many methods produce the amount of the parent substance that was initially present as a side effect of the method. E.g. isochron methods and the Ar-Ar method.
By far the most widely used method, U-Pb, takes advantage of the fact that significant amounts of lead physically and electrically can't get into minerals such as zircons at solidification; the atoms just don't fit. The only significant source of lead in zircons is radioactive decay. This is acknowledged by the few YECs who have some knowledge of the facts:
Humphreys, Baumgardner, Snelling and Austin writes:
Samples 1 through 3 had helium retentions of 58, 27, and 17 percent. The fact that these percentages are high confirms that a large amount of nuclear decay did indeed occur in the zircons. Other evidence strongly supports much nuclear decay having occurred in the past [14, pp. 335-337]. We emphasize this point because many creationists have assumed that "old" radioisotopic ages are merely an artifact of analysis, not really indicating the occurrence of large amounts of nuclear decay. But according to the measured amount of lead physically present in the zircons, approximately 1.5 billion years worth at today’s rates of nuclear decay occurred. Supporting that, sample 1 still retains 58% of all the alpha particles (the helium) that would have been emitted during this decay of uranium and thorium to lead.
{emphasis in original}
We all would appreciate it if you would learn something about the subject before making claims about it. HTH. TIA.

This message is a reply to:
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Replies to this message:
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sailorstide
Junior Member (Idle past 5026 days)
Posts: 18
From: Los Angeles,California,USA
Joined: 04-30-2006


Message 201 of 221 (560017)
05-12-2010 3:08 PM
Reply to: Message 200 by JonF
05-12-2010 2:19 PM


Re: dating game
Hub bubery and felestifization !!! Are you all realy serious !!!
My first claim was although unscientific still a legitimate one.
I am not a professor or a scholar but as I first stated way back at the beggining of this arguement was that I think that carbon dating may not be accurate as claimed to be because world conditions from year to year, century to century and millenia to millenia have there effect on solar flaring, isotopic accumulations and all around earth shifting processes.

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Taq
Member
Posts: 9973
Joined: 03-06-2009
Member Rating: 5.6


Message 202 of 221 (560018)
05-12-2010 3:12 PM
Reply to: Message 201 by sailorstide
05-12-2010 3:08 PM


Re: dating game
I am not a professor or a scholar but as I first stated way back at the beggining of this arguement was that I think that carbon dating may not be accurate as claimed to be because world conditions from year to year, century to century and millenia to millenia have there effect on solar flaring, isotopic accumulations and all around earth shifting processes.
All of these potential problems have been controlled for by comparing the carbon age with the actual age for samples of known age. These records include insects and leaf debris found in annual lake varves, tree rings, and captured CO2 in annual ice layers. These records are used to calibrate samples of unknown age.
ABE: A member here, RAZD, has a really great website explaining these correlations. You can find it here
Edited by Taq, : No reason given.

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Coragyps
Member (Idle past 734 days)
Posts: 5553
From: Snyder, Texas, USA
Joined: 11-12-2002


Message 203 of 221 (560025)
05-12-2010 4:21 PM
Reply to: Message 198 by dennis780
05-12-2010 12:55 AM


Re: dating game
Scientists have found fossilized lobster shells from lobsters that are STILL ALIVE. Carbon dating claimed them to be over a thousand years old. But the lobster was still ALIVE.
Really? Where was that published? I'll trade you some actual citations to scientific publications on fictitious 14C dates on snails and other mollusks if you'll give me one on petrified live lobsters.....

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RAZD
Member (Idle past 1405 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 204 of 221 (560043)
05-12-2010 8:07 PM
Reply to: Message 202 by Taq
05-12-2010 3:12 PM


Re: dating game -- correlations and correlations and correlations
Hi Taq,
ABE: A member here, RAZD, has a really great website explaining these correlations. You can find it here
Thanks for making the link to the article on that website, however I've also posted the same information here at
Age Correlations and An Old Earth, Version 2 No 1
This is formatted in a manner that let's doubters discuss various different points if they want to.
The problem they usually run into is that all the usual ad hoc (denial) explanations fail to explain the correlations.
In over a thousand posts on the four versions of this thread, not one creationist has been able to explain one correlation, meanwhile several additional correlations have been added.
Enjoy.

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dennis780
Member (Idle past 4776 days)
Posts: 288
From: Alberta
Joined: 05-11-2010


Message 205 of 221 (565902)
06-22-2010 12:17 AM
Reply to: Message 199 by Taq
05-12-2010 11:00 AM


Re: dating game
"Secondly, it is the ratio of parent to daughter isotope that is used. For example, if you start with 1 g of uranium after 1 halflife you will have 0.5 g of uranium and 0.5 g of lead. If you start with 5 g of uranium then after one half life you will have 2.5 g of uranium and 2.5 g of lead. It is the RATIO that is important."
Right, but you know what the initial levels of the parent substance are present. You are assuming that niether the parent or daughter substance can seep into surrounding ground, even though fossils occur in sedimentary rock. This is amusing at best. As well, any catastrophic event (ice age, flooding, etc.) would almost certainly effect levels of many substances in the area, or worldwide, depending on the severity of the occurance.
"Last I checked an hourglass is a closed system so the amount of sand in the hourglass is how much you started with."
Correct. And if an hourglass is half passed, then we can measure the rate at which the sand falls, and find out how long the hourglass has been tipped. But if you left the room, and I took sand out of the top, then you came back, you would guess incorrectly, based on the amount of sand present.
"This is what causes the older date. Scientists know all about this effect."
And yet do not account for it.
Since Carbon-14, as well as many other radioactive parent substances do not decay at a constant rate (decay rates vary depending on temperature, pressure, electron screening, as well as the fluctuation of the Van Allen belt), and the varying levels of carbon worldwide (8.5% margins), it seems almost impossible for an accurate timescale to be drawn based on any form of radioactive decay. As well, any daughter substance buried with the animal, but not occuring through radioactive decay would give false readings, making the fossil appear older.

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Coyote
Member (Idle past 2106 days)
Posts: 6117
Joined: 01-12-2008


Message 206 of 221 (565903)
06-22-2010 12:29 AM
Reply to: Message 205 by dennis780
06-22-2010 12:17 AM


Re: dating game
Since Carbon-14, as well as many other radioactive parent substances do not decay at a constant rate (decay rates vary depending on temperature, pressure, electron screening, as well as the fluctuation of the Van Allen belt), and the varying levels of carbon worldwide (8.5% margins), it seems almost impossible for an accurate timescale to be drawn based on any form of radioactive decay.
False. The decay rates do not vary wildly as you seem to be suggesting. The RATE Project set out to show that they do, using over a million dollars of creationist money, and they had to conclude that the decay rates have been constant for millions of years.
Carbon 14 dates are calibrated for atmospheric fluctuations. Tree rings, corals, glacial varves and other annular items are used to provide these calibration rates. The 8.5% figure you cite is before the calibrations, so even at its greatest error you have only 8.5% variation.
As well, any daughter substance buried with the animal, but not occuring through radioactive decay would give false readings, making the fossil appear older.
This does not apply to Carbon 14 dating. You are mixing different radiometric dating techniques. Carbon 14 is not typically used on fossils, but on wood, bone, shell, charcoal, etc.
Face it: you don't really know anything about Carbon 14 dating do you? You have to google up a few creationist websites and see what they say, and unfortunately they are lying to you. Because you haven't studied the techniques you don't know where the lies are. Those of us who have studied these techniques can spot the lies you are passing on in an instant.

Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

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Coyote
Member (Idle past 2106 days)
Posts: 6117
Joined: 01-12-2008


Message 207 of 221 (565904)
06-22-2010 12:49 AM
Reply to: Message 206 by Coyote
06-22-2010 12:29 AM


Re: dating game
I've posted these before, but here are some good links. (They will only help if you actually read them.)

ReligiousTolerance.org Carbon-14 Dating (C-14): Beliefs of New-Earth Creationists
Radiometric Dating: A Christian Perspective by Dr. Roger C. Wiens.
This site, BiblicalChronologist.org has a series of good articles on radiocarbon dating.
Are tree-ring chronologies reliable? (The Biblical Chronologist, Vol. 5, No. 1)
How does the radiocarbon dating method work? (The Biblical Chronologist, Vol. 5, No. 1)
How precise is radiocarbon dating?
Is radiocarbon dating based on assumptions?
Has radiocarbon dating been invalidated by unreasonable results?
Tree Ring and C14 Dating
Radiocarbon WEB-info Radiocarbon Laboratory, University of Waikato, New Zealand.
Radiocarbon -- full text of issues, 1959-2003.

Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

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dennis780
Member (Idle past 4776 days)
Posts: 288
From: Alberta
Joined: 05-11-2010


Message 208 of 221 (565905)
06-22-2010 12:50 AM
Reply to: Message 200 by JonF
05-12-2010 2:19 PM


Re: dating game
"By far the most widely used method, U-Pb, takes advantage of the fact that significant amounts of lead physically and electrically can't get into minerals such as zircons at solidification"
When Zircons (or other gems, such as monazite) form, they exclude lead, but can have considerable levels of Uranium. As the Uranium decays, lead is produced. Sounds logical. Except you still do not know the levels of Uranium to begin with.
quote:
As with other isochron methods, the U-Pb isochron method has been questioned in the open literature, because often an excellent line of best fit between ratios obtained from a set of good cogenetic samples gives a resultant �isochron� and yields a derived age that has no distinct geological meaning. At Koongarra, Australia, U-Th-Pb isotopic studies of uranium ore, host rocks and soils have produced an array of false isochrons that yield ages that are geologically meaningless.
Andrew A. Snelling, Ph.D.
quote:
It is not uncommon to find that �ages� derived from standard 207Pb/206Pb plots are erroneous, even though the data fit well-defined linear arrays ('isochrons').14
K.R. Ludwig, Economic Geology, 76 (1981) 89-110

This message is a reply to:
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Replies to this message:
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Coyote
Member (Idle past 2106 days)
Posts: 6117
Joined: 01-12-2008


Message 209 of 221 (565907)
06-22-2010 1:00 AM
Reply to: Message 208 by dennis780
06-22-2010 12:50 AM


Re: dating game
Sorry, that has nothing to do with Carbon 14. Try one of RAZD's correlation threads.
There really are vast differences between the various methods of radiometric dating. Please stop mixing them.

Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

This message is a reply to:
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dennis780
Member (Idle past 4776 days)
Posts: 288
From: Alberta
Joined: 05-11-2010


Message 210 of 221 (565920)
06-22-2010 2:01 AM
Reply to: Message 209 by Coyote
06-22-2010 1:00 AM


Re: dating game
", that has nothing to do with Carbon 14. Try one of RAZD's correlation threads."
I posted this to respond to what I thought I read about U-Pb dating...I can't find it now, but whoever thats for, it's there.
quote:
Beck and colleagues tested slices of a half-metre long stalagmite that grew between 45 000 and 11 000 years ago in a cave in the Bahamas. Stalagmites are calcium carbonate deposits left behind when carbon dioxide evaporates out of cave seepage water. They found that carbon-14 concentrations were twice their modern level during that period. Current records of the levels of carbon-14 in the atmosphere only cover the last 16 thousand years, and this discovery extends those records a further 30 thousand years.
Galactic cosmic rays create most of the carbon-14 in our atmosphere, while solar cosmic rays generate a smaller fraction. The Earth is partially shielded from galactic cosmic rays by its own magnetic field and the solar magnetic field, which fluctuates as the solar cycle proceeds. But these effects are predictable and are thought to have changed little in the last million years - which means they cannot explain the glut of carbon-14. Evidence from North Atlantic sediments suggests that the Earth's magnetic field may have dipped around 40 thousand years ago, but this would still only account for - at best - half of the observed peak in carbon-14 concentrations.
Beck's team concludes that either a jump in the cosmic ray flux or a fundamental change in the carbon cycle must have produced the sudden increase of carbon-14. The team speculates that a supernova shock wave could have produced a flurry of cosmic rays. "Weaker circulation of the oceans - which are the biggest reservoirs of carbon on Earth - would explain the excess of carbon-14", David Richards, joint team leader, told PhysicsWeb. If carbon-14 is carried more slowly from the surface to the depths of the ocean, he explains, the carbon-14 content of the atmosphere will rise.
Page not found – Physics World
As I said before, carbon levels are NOT constant.

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