How is carbon dating calibrated?
An excerpt from one online encyclopedia states “Dendrochronology … is used to calibrate radiocarbon ages”
It goes onto add “A benefit of dendrochronology is that it makes available specimens of once-living material accurately dated to a specific year to be used as a calibration and check of radiocarbon dating”
Following the Twelfth Nobel Symposium entitled "Radiocarbon Variations and Absolute Chronology" the calibration curve was published in a report of the symposium (also published in Scientific American, October 1971). It shows, for each year back to about 5200 B.C.E., how many years must be added to or subtracted from the radiocarbon date to make it correspond with the tree-ring date.
How is dendrochronology checked?
Professor Damon at the University of Arizona said at the Symposium: "It is reassuring to have some objective comparison, for example, with another method of dating. This is, in fact, provided by carbon-14 dating of historically dated samples."8
Is dendrochronology accurate?
No two trees have exactly the same pattern of thick and thin rings. Missing rings have to be supplied to all the patterns, in order to fit them together. Are we to believe that the analyst’s judgment is always correct in deciding where to put the missing rings? If they were inserted in different places, is it possible that the overlap might fit better in another part of the record?
Thus, an expert in tree-ring studies, A. E. Douglass, observed that for this reason, "10 out of 16 yellow pines from the lower levels of the Santa Rita Mountains south of Tucson have had to be discarded [in tree-ring study], and the junipers of northern Arizona have so many suspicious rings that it is almost impossible to work with them. Cypress trees also give much trouble."
Nevertheless, this method is somewhat helpful in approximating the "days" of certain trees. The General Sherman sequoia, still growing in the High Sierras of California, is an example. Tree expert Douglass said, in the TreeRingBulletin, that evidence in this tree "supplied an estimate of the age of the tree of 3500 years." But he added, "plus or minus 500 years."—July 1946, page 5. This is a margin of error of 15%.
Since this time others have become more reliant of the results insisting that they are conclusive to a much greater accuracy. However, Professor P. E. Damon at the University of Arizona, has said "The accuracy of tree-ring dating may be questioned by some researchers." 8
Professor Charles W. Ferguson, also of the Laboratory of Tree Ring Research at the University of Arizona says on this point: "In some instances, 5 percent or more of the annual rings may be missing along a given radius that spans many centuries. The location of such ‘missing’ rings in a specimen is verified by cross-dating its ring pattern with the ring pattern of other trees in which the ‘missing’ ring is present." 9 Since the investigator adds these "missing rings" to his chronology, it is greater than the actual number of rings counted, by five or more years for each century. So dendrochronologists add a 5% margin of error as the actual tree samples are wrong and/or don’t properly match each other!!!
Even more interesting is Ferguson’s comment about the possibility that a tree may produce two or three rings in a single year: "In certain species of conifers, especially those at lower elevations or in southern latitudes, one season’s growth increment may be composed of two or more flushes of growth, each of which may strongly resemble an annual ring" 9
Ferguson confirms that no two trees match: "The master chronology for all specimens involved is unique in its year-by-year pattern; nowhere, throughout time, is precisely the same long-term sequence of wide and narrow rings repeated, because year-to-year variations in climate are never exactly the same." 9
Wiki states “While archaeologists can use the technique to date the piece of wood and when it was felled, it may be difficult to definitively determine the age of a building or structure that the wood is in. The wood could have been reused from an older structure, may have been felled and left for many years before use, or could have been used to replace a damaged piece of wood.”
“In areas where the climate is reasonably predictable, trees develop annual rings of different properties depending on weather, rain, temperature, soil pH, plant nutrition, CO2 concentration, etc. in different years”. If a global flood occurred nearly 4500 years ago this would be anything other than predictable. If the global flood occurred one would not reach the correct result from the data. This can be likend to a maths exam. The answer for the first question might be used as the basis for all the remaining questions. If you get the first answer wrong it does not matter if your arithmetic for all the remaining questions is perfect – the answers will all be wrong.
But how does one know where a timber fragment found discarded on the ground or built into a structure is on the master chronology? Ferguson may give us a clue: "Occasionally, a sample from a specimen not yet dated is submitted for radiocarbon analysis. The date obtained indicates the general age of the sample, this gives a clue as to what portion of the master chronology should be scanned, and thus the tree-ring date may be identified more readily." 10
As I have mentioned previously dendrochronology is not simply counting one tree sample. To have any relevance to dating ancient structures in the middle east hundreds and even thousands of pieces of deadwood are compared. But when they pick up a piece of battered deadwood how do they even know where to start looking. They use radiocarbon dating techniques to give them an approx. date.
Is carbon dating accurate?
Dr. Säve-Söderbergh, of the Institute of Egyptology at the University of Uppsala, recounted this anecdote at the symposium in Uppsala Sweden in 1969:
"Carbon-14 dating was being discussed at a symposium on the prehistory of the Nile Valley. A famous American colleague, Professor Brew, briefly summarized a common attitude among archaeologists toward it, as follows:
"‘If a carbon-14 date supports our theories, we put it in the main text. If it does not entirely contradict them, we put it in a footnote. And if it is completely "out of date", we just drop it.’
“With regards the radiocarbon clock, as far back as 1976 this method of dating artifacts and finds over the past few years has been questioned by radiochemists, archaeologists and geologists. In particular discrepancies appear when dating objects from about 2000 b.c.e as the rate of radioactive carbon formation in the atmosphere has not been consistent in the past” – |Seattle Post-Intelligencer, “Radiocarbon dating wrong”, January 18 1976, p. C8|
The radiocarbon clock looked very simple and straightforward when it was first demonstrated, but it is now known to be prone to many kinds of error. After many years’ use of the method, a conference on radiocarbon chronology and other related methods of dating was held at the afore mentioned symposium. The discussions there between chemists who practice the method and archaeologists and geologists who use the results brought to light a dozen flaws that might invalidate the dates. In the years since then, little has been accomplished to remedy these shortcomings.
One nagging problem has always been to ensure that the sample tested has not been contaminated, either with modern (live) carbon or with ancient (dead) carbon. A bit of wood, for example, from the heart of an old tree might contain live sap. Or if that has been extracted with an organic solvent (made from dead petroleum), a trace of the solvent might be left in the portion analyzed. Old buried charcoal might be penetrated by rootlets from living plants. Or it might be contaminated with much older bitumen, difficult to remove. Live shellfish have been found with carbonate from minerals long buried or from seawater upwelling from the deep ocean where it had been for thousands of years. Such things can make a specimen appear either older or younger than it really is.
The most serious fault in radiocarbon-dating theory is in the assumption that the level of carbon 14 in the atmosphere has always been the same as it is now. That level depends, in the first instance, on the rate at which it is produced by cosmic rays. Cosmic rays vary greatly in intensity at times, being largely affected by changes in the earth’s magnetic field. Magnetic storms on the sun sometimes increase the cosmic rays a thousandfold for a few hours. The earth’s magnetic field has been both stronger and weaker in past millenniums. And since the explosion of nuclear bombs, the worldwide level of carbon 14 has increased substantially.
On the other hand, the proportion is affected by the quantity of stable carbon in the air. Great volcanic eruptions add measurably to the stable carbon-dioxide reservoir, thus diluting the radiocarbon. In the past century, man’s burning of fossil fuels, especially coal and oil, at an unprecedented rate has permanently increased the quantity of atmospheric carbon dioxide.
"Few archaeologists who have concerned themselves with absolute chronology are innocent of having sometimes applied this method, and many are still hesitant to accept carbon-14 dates without reservation." 18
Another said later "Archeologists [are coming] to have second thoughts about the immediate usefulness of radiocarbon age determinations simply because they come out of ‘scientific’ laboratories. The more that confusion mounts in regard to which method, which laboratory, which half-life value, and which calibration is most reliable, the less we archeologists will feel slavishly bound to accept any ‘date’ offered to us without question."
Among the more obvious possibilities of error in radiocarbon dating is the loss in integrity of the sample. (Assumption 3) If a sample is altered by contact with, or contaminated by inclusion of, material that contains older or younger radiocarbon, the analysis cannot give the right answer. But the practical archaeologist has learned what to do about it when a sample comes back from the laboratory with a date different from what he expected. As Dr. Evzen Neustupný, of the Archaeological Institute of the Czech Academy of Sciences, told the symposium: "Contamination of samples by either modern or ancient carbon can often be clearly discerned if the result of a measurement deviates considerably from the expected value." 2
To paraphrase his words, he does not recognize the contamination of the sample before he sends it in, but when he looks at it again, with the unpalatable answer attached, he can see clearly that it was contaminated.
The same expert also pointed out, relative to the importance of selecting contemporaneous samples (Assumption 4): "It should be clear, although many archaeologists seem to ignore it, that radiocarbon measurements date the age of the organic tissue of the sample, i.e., the time when it originated. The tissue of a sample dating some historical (or prehistoric) event might have been biologically dead for several decades or even centuries when it was used by ancient man. This applies to wood for building, charcoal from hearths, and most other kinds of materials." 2
This is a point that the reader would do well to keep in mind when he sees a news item that radiocarbon dating of a piece of charcoal dug up from a cave/pyramid somewhere proves that the men lived there so-and-so many thousand years ago. There are places today where a camper could pick up firewood that had grown hundreds, even thousands, of years ago (if you do not think so tell me again where the dendrochronologists are getting their wood from!!!)
One of the questions concerns the very first assumption. How sure is it that the half-life of carbon 14 is correct? Note the following comment by two experts from the radiocarbon laboratory of the University of Pennsylvania:
"What causes the most worry about the veracity of these half-life determinations is the fact that they all depend upon the same basic methods—namely, the absolute calibration of a gas counter for determination of the specific disintegration rate, and the subsequent mass spectrographic measurement of the exact quantity of C-14 that was counted. In the first phase there is the difficulty of obtaining an absolute calibration of a gas counter, and in the latter there is the problem of precise dilution and introduction of the ‘hot’ C-14 into the mass spectrograph. An error caused by adsorption of C-14 on the walls of the containers may be prevalent and of roughly the same magnitude in all of the half-life determinations. Clearly, there is need for an entirely independent approach and technique before one can say with certainty what is the true value of the half-life of C-14." 3
Libby himself was aware of this limitation in the accuracy of half-life. In 1952, writing of the vital importance of measuring absolute disintegration rates, he said: "It is to be hoped that further measurements of the half-life of radiocarbon will be made, preferably by entirely different techniques." 4 As yet this hope has not been realized.
What about the constancy of cosmic rays? (Assumption 2a) Observations have shown that they are not at all constant. Several factors are now known that cause large fluctuations in the cosmic rays.
One of these is the strength of the earth’s magnetic field. This affects the cosmic rays, which are mostly protons (charged nuclei of hydrogen atoms), by deflecting the less energetic particles away from the atmosphere. When the earth’s magnetic field becomes stronger, fewer cosmic rays reach the earth and less radiocarbon is produced. When the earth’s magnetic field becomes weaker, more cosmic rays reach the earth and more radiocarbon is produced.
Studies indicate that the magnetic field doubled in strength from about 5,500 years ago to about 1,000 years ago, and is now decreasing again. This effect alone can account for the needed correction of almost 1,000 years in the older dates.
Solar phenomena also cause large changes. The sun’s magnetic field extends far out into space, even beyond the earth’s orbit. Its strength changes, although not very regularly, along with the sunspot cycle of about eleven years, and this also affects the number of cosmic rays reaching the earth.
Then there are the solar flares. These great streams of incandescent gas burst out of the sun’s surface sporadically and eject enormous numbers of protons. Those that reach the earth produce carbon 14. This makes for an unpredictable surplus in the supply. A table and a graph in the report show the production of carbon 14 from typical flares. On February 23, 1956, there was a flare that produced as much carbon 14 in a few hours as in a whole year of average cosmic radiation. It is obviously impossible to include this kind of effect in the corrections to the radiocarbon clock, for no one knows whether the flares in past millenniums were more or less active than they are now.
The intensity of cosmic rays entering the solar system from the galaxy is another little-known factor. Geochemical scientists have tried, by measuring the very faint radioactivities of various elements produced in meteorites by cosmic rays, to get some idea of average intensities in the past. However, the results do not help much in giving the desired assurance of constancy over the past 10,000 years.
The radiocarbon theory would be in a stronger position (though still not invulnerable) with respect to the above objections if it could be shown that the radiocarbon is today decaying as fast as it is being formed. (Assumption 2c) If this is found not to be true, then the assumption of a constant inventory of carbon 14 is also proved untrue, and the assumed constant activity of radiocarbon is put on a precarious tightrope between two mooring posts that may be rising independently of each other.
The production rate is very difficult to calculate. Libby attempted to do this with the best data available up to 1952. He found a production corresponding to about nineteen atoms of radiocarbon per second for every gram of carbon in the reservoir. This was somewhat higher than his measurement of sixteen disintegrations per second. But in view of the complexity of the problem and the rough estimate that had to be made of so many factors, he regarded this as agreeing well enough with his assumptions.
Seventeen years later, with better data and better understanding of the process, can this be calculated more precisely? The experts at the symposium could say nothing more definite than that the radiocarbon is being produced at a rate probably between 75 percent and 161 percent of the rate at which it is decaying. The lower figure would mean that the amount of radiocarbon is presently decreasing; the higher figure, that it is increasing. The measurement gives no assurance that it is constant, as the radiocarbon theory demands. Again, recourse is taken to the view that "the relative constancy of the C-14 activity in the past suggests that [this ratio] must be confined to a much narrower range of values." 5 So one assumption is used to justify another.
Not only the inventory of carbon 14, but also the stable carbon 12 in the exchange reservoir, must be constant to keep the radiocarbon clock synchronized. (Assumption 2b) Have we good reason to believe that this assumption is valid?
Since there is about sixty times as much carbon in the ocean as in the atmosphere, we are concerned chiefly about that oceanic reservoir. This point came up for discussion at the Uppsala meeting, where the consensus was that what they call an "Ice Age" could cause major perturbations. Libby had pointed out this possibility in 1952:
"The possibility that the amount of carbon in the exchange reservoir has altered appreciably in the last 10,000 or 20,000 years turns almost entirely on the question as to whether the glacial epoch, which, as we will see later, appears to reach into this period, could have affected the volume and mean temperatures of the oceans appreciably." 6
Mention of the volume of the oceans immediately raises in the mind of the Bible student the possibility of major dislocations in the radiocarbon clock at the time of the global deluge of Noah’s day, nearly 4,500 years ago.
Don’t forget even the father of evolution Darwin himself talks about clear evidence, clearer than a the fact that a burnt down house once burned, that water once covered the highlands in Britain and the wide open spaces of America on page 269. He continues this line of thought and on pages 274 and 275 explains that this recent mini ice age resulted in water covering much of the globe and was actually “simultaneous throughout the world”. He speaks of “huge boulders transported far from their parent source”. From memory he suggested this must have occurred in the past 10,000 years.
The oceans must certainly have been much greater in extent and depth after the Flood. This in itself would not increase the amount of carbonate in the ocean; it would merely dilute it. The amounts of carbon 14 and carbon 12, as well as their ratio, which determines the specific activity, would not have been changed merely by the fall of the water. However, the increased volume would give the ocean the capacity ultimately to carry a much larger load of dissolved carbonate.
And adjustments in the crust of the earth would be expected because of the greatly increased weight of water on the ocean basins. This pressure would be greater than that over the continents. It would push the underlying plastic mantle away from the ocean beds toward the continents, thus lifting them to new heights. This would expose rock surfaces to increased erosion, including the limestones in the beds of shallow seas that geologists show in low-lying continental areas in their maps of Pliocene times.
So, beginning shortly after the Flood, the oceanic reservoir of carbonate would steadily increase until it reached the concentration we have today. Then, rather than assume that the carbonate reservoir has been constant, we should consider the possibility that it has been gradually increasing over the past 4,350 years.
How would the Flood affect the carbon 14? Since the Bible indicates that the water that fell in the Deluge was previously suspended in some way above the earth’s atmosphere, it must have impeded the entrance of cosmic rays and hence the production of radiocarbon. If uniformly distributed in a spherical shell, it could have prevented completely the formation of radiocarbon. However, it is not necessary to assume this; the water canopy might have been thicker over the equatorial parts than over the poles, thus admitting cosmic rays at low intensities. In any case, the removal of this shield by its falling to the surface would increase the rate of producing carbon 14.
Thus, we should expect that, after the Flood, both the radioactive carbon 14 and the stable carbon 12 in the oceanic reservoir would begin to increase rapidly. Remember that it is the ratio of carbon 14 to carbon 12 that fixes the specific activity. So, depending on just how quickly the erosion of the land added carbonate to the seas, the activity might either increase or decrease. Indeed, it would be possible, though not probable, that the growth of one would just balance the growth of the other; in that case, the radiocarbon clock would have continued to run uniformly right through the Flood. Libby pointed out the possibility that such a fortuitous balancing could bring about the "agreement between the predicted and observed radiocarbon contents of organic materials of historically known age." 7 But he did not prefer this explanation.
Since the inventories of carbon 14 and carbon 12 are independent of each other, it is possible to postulate values that would account for the excessive ages reported on old samples. For example, if we assume that the specific activity before the Flood was about half its present value, all pre-Flood specimens would appear to be about 6,000 years older than they really are. This would also be true for a while afterward, but with a rapid erosion of carbonate in the centuries after the Flood, the error would be reduced. It appears that by about 1500 B.C.E. the activity had approached its present value, since radiocarbon ages seem to be nearly right since then.
These are some of the recognized problems that beset the radiocarbon chronology. There are others that have hardly been considered, and possibly some yet unthought of. These are the reasons why the theory set forth many years ago is no longer tenable. It is just not possible, merely by measuring the radiocarbon in a sample and comparing it with the present-day activity, to tell with any assurance the age of the sample. As we have seen some have tried to support their conclusions with dendrochronology.
However, bearing in mind our review of dendrochronology above, it may well be that neither of these scientific chronologies are as independent as their supporters would like to believe. Perhaps they are depending on circular reasoning. Do the radiocarbon workers believe their dating is correct because the tree-ring laboratories verify it? And are the tree-ring researchers satisfied that their master chronology is correct because the radiocarbon dates fit on it? As long as they are within the channel marked by historical buoys, they both steer a reasonable course, but in the misty depths beyond, they sail away with no constraint but to keep one another in sight.
Lest you think this is an unfair judgment, just took at some of the crosswinds and countercurrents that the radiocarbon pilot has to face:
(1) The half-life of radiocarbon is not as certainly known as the scientists would like.
(2) The cosmic rays, never steady, may have been much stronger or weaker in the past 10,000 years than is generally believed.
(3) Solar flares change the level of radiocarbon—how much in the past nobody knows.
(4) The earth’s magnetic field changes fitfully on a short time scale, and so radically over thousands of years that even the north and south poles are reversed. Scientists do not know why.
(5) Radiocarbon scientists admit that an "Ice Age" could have affected the radiocarbon content of the air, by changing the volume and temperature of the ocean water, but they are not sure how great these changes were.
(6) They ignore all the evidence, both scientific and Biblical, for a worldwide deluge nearly forty-five centuries ago, so they do not recognize the drastic effects that such a cataclysmic event must have had on the samples they measure from that period.
(7) Mixing of radiocarbon between the atmosphere and ocean can be affected by changes in climate or weather, but no one knows how much.
(8) Mixing of radiocarbon between the surface layers and the deep ocean has an effect, very imperfectly understood.
(9) The count of tree rings, used to calibrate the radiocarbon clock, is cast into doubt by the possibility of greatly different climatic conditions in past ages.
(10) The radiocarbon content of old trees may be changed by diffusion of sap and resin into the heartwood.
(11) Buried samples can either gain or lose radiocarbon through leaching by groundwater or by contamination.
(12) It is never certain that the sample selected to date an event truly corresponds with it. It is only more or less probable, in the light of the archaeological evidence at the site.
This is by no means a complete listing of the pitfalls that beset radiocarbon dating, but it should be enough to give a person pause before he simply believes what wiki or some scientist somewhere tells him.
If the evolutionists’ ideas about man’s having been around for a million years were correct, surely we would expect to find a much larger number of artifacts dated back 10,000 or 20,000 years, within the range of carbon 14. Why do nearly all the specimens fall within just the past 6,000 years? We do not expect a scientific measurement to speak with the authority of a trusted eyewitness. It can only offer circumstantial evidence. But statistically speaking, the radiocarbon clock throws the weight of its testimony overwhelmingly on the side of the creation account, and against the evolution hypothesis, of man’s origin.
A recent development in radiocarbon dating is a method for counting not just the beta rays from the atoms that decay but all the carbon-14 atoms in a small sample. This is particularly useful in dating very old specimens in which only a tiny fraction of the carbon 14 is left. Out of a million carbon-14 atoms, only one, on the average, will decay every three days. This makes it quite tedious, when measuring old samples, to accumulate enough counts to distinguish the radioactivity from the cosmic-ray background.
But if we can count all the carbon-14 atoms now, without waiting for them to decay, we can gain a millionfold in sensitivity. This is accomplished by bending a beam of positively charged carbon atoms in a magnetic field to separate the carbon 14 from the carbon 12. The lighter carbon 12 is forced into a tighter circle, and the heavier carbon 14 is admitted through a slit into a counter.
This method, although more complicated and more expensive than the beta-ray-counting method, has the advantage that the amount of material needed for a test is a thousand times less. It opens up the possibility of dating rare ancient manuscripts and other artifacts from which a sample of several grams that would be destroyed in testing just cannot be had. Now such articles can be dated with just milligrams of sample.
One suggested application of this would be to date the Shroud of Turin, which some believe Jesus’ body was wrapped in for burial. If radiocarbon dating was to show that the cloth is not that old, it would confirm the suspicions of doubters that the shroud is a hoax. Until now, the archbishop of Turin has refused to donate a sample for dating because it would take too large a piece. But with the new method, one square centimeter would be enough to determine whether the material dates from the time of Christ or only from the Middle Ages.
In any event, attempts to extend the time range have little significance as long as the greater problems remain unsolved. The older the sample is, the more difficult it is to ensure the complete absence of slight traces of younger carbon. And the farther we try to go beyond the few thousand years for which we have a reliable calibration, the less we know about the atmospheric level of carbon 14 in those ancient times.
Several other methods have been studied for dating events in the past. Some of these are related indirectly to radioactivity, such as the measurement of fission tracks and radioactive halos. Some involve other processes, such as the deposition of varves (layers of sediment) by streams flowing from a glacier and the hydration of obsidian artifacts.
The efforts to strengthen the mutual support of the two chronologies are plagued by another problem that occasioned considerable discussion among the experts. Even in radiocarbon analysis of those samples of bristlecone pine that now serve as the basis for all other radiocarbon dates, the possibility of sample alteration must be considered. It is known that inorganic substances, such as the limestone of shellfish and the carbonate in bones, are very susceptible to exchange with dissolved carbonates, either older or younger. For this reason they are almost useless for dating. Organic substances, such as cellulose, are regarded as unlikely to exchange. The live sap in a tree can be washed out of the dead wood, but if it has been circulating through the wood for centuries or millenniums, can we be sure that it has not partly replaced the decaying carbon 14?
Unlike the sap, resin is difficult to remove. Ferguson has referred to "the highly resinous nature" of bristlecone pine wood. 12 The experts agreed that resin from younger wood moves into the older wood, where it can cause errors. "The diffusion inward of the resin certainly is a reasonable result." 13 Also, "This resin problem is important, particularly as the correction increases as one goes further into the tree." 13 In one experiment, the extracted resin was apparently 400 years younger than the wood.
However, the experts disagreed as to how effective their chemical treatments are. One said that boiling the wood successively in acid and alkali "removes all of the resin." 14 Another said: "In my opinion, the resins in bristlecone pines cannot be removed completely by treatment with inorganic chemicals." 14 But when they use organic chemical solvents, they have to worry about whether the solvent has been completely removed afterward, because just a little modern carbon from it could apparently rejuvenate a sample of ancient wood. Of course, they work conscientiously to exclude all these errors, but are they completely successful? How sure can we be?
Examples of changes in dating:
In an article in the Daily Telegraph entitled “Earliest known European died in Torquay” dated Thursday 03 November 2011 regarding a fragment of a jawbone said to be from an ancestor of homo sapiens the article reported how the previous date for the sample given was 35000 years old. It concluded with the reports from re testing of the fragment which indicated the previous dating techniques were in error by about 15%.
In an article in the New York Times entitled “Errors are feared in carbon dating” dated 31 May 1990 reported how Dr. Alan Zindler, a professor of geology and his colleagues “at the Lamont-Doherty Geological Laboratory of Columbia University at Palisades, N.Y., reported today in the British journal Nature that some estimates of age based on carbon analyses were wrong by as much as 3,500 years. They arrived at this conclusion by comparing age estimates obtained using two different methods - analysis of radioactive carbon in a sample and determination of the ratio of uranium to thorium in the sample'' . Thus the dating error of the carbon dating was around 15%. It continued “scientists have long recognized that carbon dating is subject to error because of a variety of factors, including contamination by outside sources of carbon… The group theorizes that large errors in carbon dating result from fluctuations in the amount of carbon 14 in the air”.
When scientists first carried out radiocarbon dating of egyptian sites in 1984 their radiocarbon dates suggested the history (using Cambridge Ancient History dates) was out by some 374 years! In 1995 when the same team revisited and took further samples the new radio carbon dates were 200 years younger than their initial carbon tests i.e. only 100 to 200 years than the Cambridge Ancient History dates.
The Egyptologist Kate Spence published her thoughts on the Egyptian rulers ascension dates in December 2000 and recommended due to her astronomical observations the pyramids must have been built around 74 years later than the commonly accepted dates for the construction of the pyramids.
Before radiocarbon, astronomical observations, and other modern dating techniques were introduced the various secular historians over the past few centuries have dated the Egyptian dynasties at various dates ranging from between 1000 years younger than current to 2000 years older than current.
After chopping “Prometheus” (also known as WPN-114) down and carrying out laboratory tests on a cross section a ring count was conducted by Currey giving an estimated age of 4844. Donald Graybill, also of the University of Arizona, increased the count a few years later to 4862. Other sources have sought to add years to the scientists count in case they missed some and it is not uncommon to see such reports suggesting that the tree had in fact lived for 5000 years. This is an error of nearly 4% between different dendrochronologists opinions.
Numbered References:
1. RadiocarbonDating, by W. F. Libby, 1952, p. 72.
2. NobelSymposium12:RadiocarbonVariationsandAbsoluteChronology, 1970, p. 25.
3. E. K. Ralph and H. N. Michael, Archaeometry, Vol. 10, 1967, p. 7.
4. RadiocarbonDating, p. 41.
5. NobelSymposium12, p. 522.
6. RadiocarbonDating, p. 29.
7. Ibid., p. 32.
8. NobelSymposium12, p. 576.
9. C. W. Ferguson, Science, Vol. 159, Feb. 23, 1968, p. 840.
10. Ibid., p. 845.
11. Ibid., p. 842.
12. Ibid., p. 839.
13. NobelSymposium12, p. 272.
14. Ibid., p. 273.
15. Ibid., p. 167.
16. Ibid., p. 216.
17. Ibid., p. 219.
18. Ibid., p. 35.