This is the principle behind long-established techniques such as radiocarbon dating, which has been widely used in archaeology. Diamonds. that increasing atmospheric carbon dioxide causes global warming. The open squares and open diamonds are proxy measurements obtained from .. B. W. Rust. Figure 9: Extrapolations of the temperature models (19). Learn some interesting facts about the element carbon (atomic number 6 or element in pencils, as a lubricant, and to protect against rust; while charcoal is used to remove toxins, tastes, and odors. The isotope Carbon is used in radiocarbon dating. . Everything You Need to Know About Diamonds.
The creationists who quote Kieth and Anderson never tell you this, however. A sample that is more than fifty thousand years old shouldn't have any measurable C Coal, oil, and natural gas are supposed to be millions of years old; yet creationists say that some of them contain measurable amounts of C, enough to give them C ages in the tens of thousands of years.
How do you explain this? Radiocarbon dating doesn't work well on objects much older than twenty thousand years, because such objects have so little C left that their beta radiation is swamped out by the background radiation of cosmic rays and potassium K decay.
Younger objects can easily be dated, because they still emit plenty of beta radiation, enough to be measured after the background radiation has been subtracted out of the total beta radiation. However, in either case, the background beta radiation has to be compensated for, and, in the older objects, the amount of C they have left is less than the margin of error in measuring background radiation. As Hurley points out: Without rather special developmental work, it is not generally practicable to measure ages in excess of about twenty thousand years, because the radioactivity of the carbon becomes so slight that it is difficult to get an accurate measurement above background radiation.
K decay also forms plenty of beta radiation. Stearns, Carroll, and Clark point out that ". This radiation cannot be totally eliminated from the laboratory, so one could probably get a "radiocarbon" date of fifty thousand years from a pure carbon-free piece of tin.
However, you now know why this fact doesn't at all invalidate radiocarbon dates of objects younger than twenty thousand years and is certainly no evidence for the notion that coals and oils might be no older than fifty thousand years.
Creationists such as Cook claim that cosmic radiation is now forming C in the atmosphere about one and one-third times faster than it is decaying. If we extrapolate backwards in time with the proper equations, we find that the earlier the historical period, the less C the atmosphere had. If we extrapolate - page 25 - as far back as ten thousand years ago, we find the atmosphere would not have had any C in it at all. If they are right, this means all C ages greater than two or three thousand years need to be lowered drastically and that the earth can be no older than ten thousand years.
Yes, Cook is right that C is forming today faster than it's decaying. However, the amount of C has not been rising steadily as Cook maintains; instead, it has fluctuated up and down over the past ten thousand years.
How do we know this? From radiocarbon dates taken from bristlecone pines. There are two ways of dating wood from bristlecone pines: Since the tree ring counts have reliably dated some specimens of wood all the way back to BC, one can check out the C dates against the tree-ring-count dates. Admittedly, this old wood comes from trees that have been dead for hundreds of years, but you don't have to have an 8,year-old bristlecone pine tree alive today to validly determine that sort of date.
It is easy to correlate the inner rings of a younger living tree with the outer rings of an older dead tree. The correlation is possible because, in the Southwest region of the United States, the widths of tree rings vary from year to year with the rainfall, and trees all over the Southwest have the same pattern of variations. When experts compare the tree-ring dates with the C dates, they find that radiocarbon ages before BC are really too young—not too old as Cook maintains.
For example, pieces of wood that date at about BC by tree-ring counts date at only BC by regular C dating and BC by Cook's creationist revision of C dating as we see in the article, "Dating, Relative and Absolute," in the Encyclopaedia Britannica. So, despite creationist claims, C before three thousand years ago was decaying faster than it was being formed and C dating errs on the side of making objects from before BC look too young, not too old.
But don't trees sometimes produce more than one growth ring per year? Wouldn't that spoil the tree-ring count?
RATE’s Radiocarbon: Intrinsic or Contamination?
If anything, the tree-ring sequence suffers far more from missing rings than from double rings. This means that the tree-ring dates would be slightly too young, not too old. Of course, some species of tree tend to produce two or more growth rings per year. But other species produce scarcely any extra rings. Most of the tree-ring sequence is based on the bristlecone pine. This tree rarely produces even a trace of an extra ring; on the contrary, a typical bristlecone pine has up to 5 percent of its rings missing.
Concerning the sequence of rings derived from the bristlecone pine, Ferguson says: In the growth-ring analyses of approximately one thousand trees in the White Mountains, we have, in fact, found no more than three or four occurrences of even incipient multiple growth layers. Hence at least some of the missing rings can be found. Even so, the missing rings are a far more serious problem than any double rings.
Other species of trees corroborate the work that Ferguson did with bristlecone pines. Before his work, the tree-ring sequence of the sequoias had been worked out back to BC. The archaeological ring sequence had been worked out back to 59 BC. The limber pine sequence had been worked out back to 25 BC.
The radiocarbon dates and tree-ring dates of these other trees agree with those Ferguson got from the bristlecone pine. But even if he had had no other trees with which to work except the bristlecone pines, that evidence alone would have allowed him to determine the tree-ring chronology back to BC.
See Renfrew for more details. So, creationists who complain about double rings in their attempts to disprove C dating are actually grasping at straws. If the Flood of Noah occurred around BC, as some creationists claim, then all the bristlecone pines would have to be less than five thousand years old. This would mean that eighty-two hundred years worth of tree rings had to form in five thousand years, which would mean that one-third of all the bristlecone pine rings would have to be extra rings.
Creationists are forced into accepting such outlandish conclusions as these in order to jam the facts of nature into the time frame upon which their "scientific" creation model is based.
Barnes has claimed that the earth's magnetic field is decaying exponentially with a half-life of fourteen hundred years. Not only does he consider this proof that the earth can be no older than ten thousand years but he also points out that a greater magnetic strength in the past would reduce C dates.
Now if the magnetic field several thousand years ago was indeed many times stronger than it is today, there would have been less cosmic radiation entering the atmosphere back then and less C would have been produced.
Therefore, any C dates taken from objects of that time period would be too high. How do you answer him? Like Cook, Barnes looks at only part of the evidence.
Answers to Creationist Attacks on Carbon-14 Dating
What he ignores is the great body of archaeological and geological data showing that the strength of the magnetic field has been fluctuating up and down for thousands of years and that it has reversed polarity many times in the geological past. So, when Barnes extrapolates ten thousand years into the past, he concludes that the magnetic field was nineteen times stronger in BC than it is today, when, actually, it was only half as intense then as now.
The main sources are generally the following: Specifically, this technique underestimates both the ion source memory and mass spectrometer backgrounds. Recent tests suggest, not surprisingly, that this effect also applies to the sample surface itself, causing ion source memory to be sample-surface-dependent due to different sticking coefficients for carbon-containing molecules in the ion source.
Differences in ion sources, beamline components, mass separation techniques, and detectors will cause the instrument background to vary significantly from laboratory to laboratory.
Laboratory contamination and instrument background can also vary with time at a single laboratory. Many unexpected sources can introduce additional contamination.
- RATE’s Radiocarbon: Intrinsic or Contamination?
- Tiny Inclusions Reveal Diamond Age and Earth’s History: Research at the Carnegie Institution
Thus frequent characterizations of the measurement background are necessary. AMS laboratories have been able to identify and reduce many sources of contamination through years of care and attention. The remaining amounts of laboratory contamination and instrument background vary between laboratories but are well characterized by frequent use of process blanks.Joan Baez, Diamonds and Rust - Live, 1975
Frequent intercomparisons between AMS laboratories demonstrate the effectiveness of this approach. For example, the Fourth International Radiocarbon Intercomparison FIRI included identical samples of very old wood with a radiocarbon content of about 0. The mean value measured by over 30 AMS laboratories was 0. These low variations demonstrate very good consistency between laboratories, in spite of the presence of laboratory contamination and instrument background.
Interestingly, none of these laboratories found either of the Kauri wood samples to be at or below measurement background levels. He has selectively divided these into two groups for re-analysis: The remaining samples, including marbles of uncertain origin and a few reprocessed samples, were not re-analyzed.
The Precambrian geological subset Baumgardner analyzed has a mean radiocarbon content of 0. The Phanerozoic biological samples have a mean radiocarbon content of 0. Baumgardner fails to note that nearly all of these geological samples are actually of geological graphite, so did not undergo the sample chemistry required for the biological samples.
Geological graphite typically requires only a mechanical surface cleaning with no chemical processing. This omission is crucial, because Baumgardner asserts evidence for increased intrinsic radiocarbon in the biological samples on the basis of these lower results from the geological samples.
Baumgardner also omits two important geological graphite samples from his analysis, namely entries 21 and 40 in his Table 1 . These samples were identical to two natural graphite samples, entries 62 and 79 respectively, but were combusted and re-graphitized in the laboratory using identical chemistry to biological samples. This procedure provided controlled characterizations of contamination from sample chemistry, which added 0.
The highest value of 0. Jull et al characterize a total process background of 0. Thus the main difference Baumgardner sees between geological and biological samples is contamination introduced by sample chemistry.
While this conclusion explains the higher values for the biological samples in general, it does not account for all the details. Some biological samples do have radiocarbon levels not explainable by sample chemistry. These samples are mostly coals and biological carbonates, both of which are prone to in situ contamination.
Coal is notorious for contamination . Uranium is often found in or near coal, releasing neutrons that generate radiocarbon in the coal from nitrogen. Mobile humicacids are almost always present and can transport more recent carbon to the coal. Microbial growth can incorporate modern carbon from groundwater while in situ and from air after sample collection. Coal can easily adsorb atmospheric CO2 after collection. Carbonates often exhibit anomalous radiocarbon values, potentially becoming contaminated by adsorption of atmospheric CO2 .
Nadeau et al detail anomalies with marine carbonates, i. But these anomalies are specific to carbonates and do not apply to other materials, e.
I agree that these large variations suggest contamination, but the main contributor seems to be sample chemistry contamination, not in situ contamination.
Baumgardner also concludes that the geological samples show evidence of intrinsic radiocarbon with values above instrument background. But their radiocarbon content of 0. More evidence against intrinsic radiocarbon appears in multi-laboratory intercomparisons. These low variations show very good consistency between laboratories.
Each laboratory used separate process blanks to characterize and subtract total background. Measurements of both materials show large variations, suggesting contamination.
Coal Baumgardner claims that his coal results of 0. The measurements also show relatively large variations, suggesting contamination. The expert who prepared and measured the RATE samples suspects that the coal samples had been contaminated before reaching his laboratory, probably in situ. As mentioned earlier, coal is easily contaminated both in situ and after collection.
Though precautions were taken, the coal samples may have also been contaminated while stored in a DOE geology laboratory refrigerator .
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Geology laboratories often have elevated levels of radiocarbon due to tracer studies, neutron activation studies, and dust from uranium-bearing rocks. Carbon is highly mobile and contamination can spread through an entire laboratory and persist for decades .
Thus coal exists that shows no evidence of intrinsic radiocarbon. Diamond Diamond is difficult to combust. The RATE samples apparently required modifications to the normal procedure , presumably higher combustion temperatures and longer combustion times, likely increasing the sample chemistry contamination.
The samples were reportedly pitted and may have been subjected to previous analyses and to unknown contamination. This much lower value for unprocessed diamond provides strong evidence that their processed diamond samples had been contaminated, most likely by the modified sample chemistry.
Taylor and Southon have also measured unprocessed diamond, finding a similar range of 0. They interpret this result as their instrument background, primarily due to ion source memory.