How Good are those Young-Earth Arguments: Radiocarbon Dating

Radiocarbon dating

what is the age limit of radiocarbon dating

Moritz published details of the twenty ornamented pages. What happens when something is dated as being very old, but shows little or no physical signs of relative aging? In most instances, the material being carbon-dated is much more well-preserved than the fragments of who-knows-what obtained from dinosaur fossils.

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Huxley challenged Kelvin's assumptions. But how can such layers which show little if any evidence of interim erosion have been laid down thousands much less millions of years apart in time? However, as von Bothmer has noted, the radiocarbon dating gives a slightly earlier date. This is significant erosion and there should be evidence of this sort of erosion if the time gap between flow was really 36, years. Porphyritic dacite, which solidified on the surface of the lava dome in , gives a whole rock K-Ar 'age ' of 0. Multiple papers have been published both supporting and opposing the criticism. Consequently, we are no longer able to provide radiocarbon services in support of your anti-scientific agenda.

Also, several different measurements are needed from various locations and materials within the specimen. This is different from the normal single point test used with the other "generic" methods. To make the straight line needed for isochron dating each group of measurements parent - P, daughter - D, daughter isotope - Di is plotted as a data point on a graph.

The X-axis on the graph is the ratio of P to Di. For example, consider the following isochron graph: Obviously, if a line were drawn between these data points on the graph, there would be a very nice straight line with a positive slope.

Such a straight line would seem to indicate a strong correlation between the amount of P in each sample and the extent to which the sample is enriched in D relative to Di. Obviously one would expect an increase in the ratio of D as compared with Di over time because P is constantly decaying into D, but not into Di.

So, Di stays the same while D increases over time. But, what if the original rock was homogenous when it was made? What if all the minerals were evenly distributed throughout, atom for atom? What would an isochron of this rock look like? It would look like a single dot on the graph. Because, any testing of any portion of the object would give the same results.

The funny thing is, as rocks cool, different minerals within the rock attract certain atoms more than others. Because of this, certain mineral crystals within a rock will incorporate different elements into their structure based on their chemical differences. However, since isotopes of the same element have the same chemical properties, there will be no preference in the inclusion of any one isotope over any other in any particular crystalline mineral as it forms.

So, when put on an isochron graph, each mineral will have the same Y-value. Since a perfectly horizontal line is likely obtained from a rock as soon as it solidifies, such a horizontal line is consistent with a "zero age. Time might still be able to be determined based on changes in the slope of this horizontal line. As time passes, P decays into D in each sample. That means that P decreases while D increases.

This results in a movement of the data points. Each data point moves to the left decrease in P and upwards increase in D. Since radioactive decay proceeds in a proportional manner, the data points with the most P will move the most in a given amount of time. Thus, the data points maintain their linear arrangement over time as the slope between them increases. The degree of slope can then be used to calculate the time since the line was horizontal or "newly formed".

The slope created by these points is the age and the intercept is the initial daughter ratio. The scheme is mathematically sound. The nice thing about isochrons is that they would seem to be able to detect any sort of contamination of the specimen over time. If any data point became contaminated by outside material, it would no longer find itself in such a nice linear pattern. Thus, isochrons do indeed seem to contain somewhat of an internal indicator or control for contamination that indicates the general suitability or unsuitability of a specimen for dating.

So, it is starting to look like isochron dating has solved some of the major problems of other dating methods. However, isochron dating is still based on certain assumptions. All areas of a given specimen formed at the same time. The specimen was entirely homogenous when it formed not layered or incompletely mixed. Limited Contamination contamination can form straight lines that are misleading.

Isochrons that are based on intra-specimen crystals can be extrapolated to date the whole specimen. Given these assumptions and the above discussion on isochron dating, some interesting problems arise as one considers certain published isochron dates. So, what exactly is a whole-rock isochron? Whole-rock isochrons are isochrons that are based, not on intra-rock crystals, but on variations in the non-crystalline portions of a given rock.

In other words, sample variations in P are found in different parts of the same rock without being involved with crystalline matrix uptake.

This is a problem because the basis of isochron dating is founded on the assumption of original homogeny. If the rock, when it formed, was originally homogenous, then the P element would be equally distributed throughout.

Over time, this homogeny would not change. Thus, any such whole-rock variations in P at some later time would mean that the original rock was never homogenous when it formed. Because of this problem, whole-rock isochrons are invalid, representing the original incomplete mixing of two or more sources. Interestingly enough, whole rock isochrons can be used as a test to see if the sample shows evidence of mixing. If there is a variation in the P values of a whole rock isochron, then any isochron obtained via crystal based studies will be automatically invalid.

The P values of various whole-rock samples must all be the same, falling on a single point on the graph. If such whole-rock samples are identical as far as their P values, mixing would still not be ruled out completely, but at least all available tests to detect mixing would have been satisfied. And yet, such whole-rock isochrons are commonly published.

For example, many isochrons used to date meteorites are most probably the result of mixing since they are based on whole-rock analysis, not on crystalline analysis. There are also methods used to detect the presence of mixing with crystalline isochron analysis.

If a certain correlation is present, the isochron may be caused by a mixing. However, even if the correlation is present, it does not mean the isochron is caused by a mixing, and even if the correlation is absent, the isochron could still be caused by a more complex mixing Woodmorappe, , pp. Therefore such tests are of questionable value. Interestingly, mainstream scientists are also starting to question the validity of isochron dating.

The determination of accurate and precise isochron ages for igneous rocks requires that the initial isotope ratios of the analyzed minerals are identical at the time of eruption or emplacement. Studies of young volcanic rocks at the mineral scale have shown this assumption to be invalid in many instances.

Variations in initial isotope ratios can result in erroneous or imprecise ages. Nevertheless, it is possible for initial isotope ratio variation to be obscured in a statistically acceptable isochron. Independent age determinations and critical appraisal of petrography are needed to evaluate isotope data. If initial isotope ratio variability can be demonstrated, however, it can be used to constrain petrogenetic pathways.

But then,] The cooling history will depend on the volume of magma involved and its starting temperature, which in turn is a function of its composition. If the initial variation is systematic e. In short, isochron dating is not the independent dating method that it was once thought. As with the other dating methods discussed already, isochron dating is also dependent upon "independent age determinations". Isochrons have been touted by the uniformitarians as a fail-safe method for dating rocks, because the data points are supposed to be self-checking Kenneth Miller used this argument in a debate against Henry Morris years ago.

Now, these geologists, publishing in the premiere geological journal in the world, are telling us that isochrons can look perfect on paper yet give meaningless ages, by orders of magnitude, if the initial conditions are not known, or if the rocks were open systems at some time in the past?! That sounds like what young earth creationists have been complaining about all along.

But then, these geologists put a happy face on the situation. The problem is that it is starting to get really difficult to find a truly independent dating method out of all the various dating methods available.

Furthermore, because most upper crustal rocks cooled below annealing temperatures long after their formation, early formed lead rich in Pb is locked in annealed sites so that the leachable component is enriched in recently formed Pb The isotopic composition of the leachable lead component then depends more on the cooling history and annealing temperatures of each host mineral than on their geological age; and the axiom that Pb isotopes cannot be fractionated in the natural environment, is invalid.

Although these experiments are based on a strong Hf attack on zircons, we believe, given the widespread U anomalies of several hundred percent observed in groundwater Osmond and Cowart , that they apply to the differential mobility of radiogenic Pb isotopes on a local and global scale.

Also, consider the following excerpt concerning ancient zirons from the Gabbro-Peridotite Complex of the Mar: Zircon age calculations on the base of Upb systematics have been complicated by high share of common Pb and uncertainty of its isotope composition.

Common lead was captured in the process of zircon crystallization, perhaps, by mineral and fluid inclusions. But there is a small share of inherited zircon substance with the age of 3. Thus, the discordia itself obtained by us is interpreted as a result of mixture of newly formed young zircon with some share of Archean zircon presented in each studied crystal.

Also, if errors for individual zircon tests are too large, these values are simply discarded. This enhances the mobility of U and especially Pb. So, how confident can one be in zircon dates who's published Pb levels range from very high to very low? It seems to me that quite often published U-Pb and Pb-Pb dates do in fact involve fairly significant Pb levels.

Of course, if the level of Pb is too high, the data obtained is not calibrated, but is simply discarded. Doesn't this mess up the idea that all lead in zircons must be the result of radioactive decay? It is also of interest in regard to radiometric dating that Robert Gentry claims to have found "squashed" polonium haloes as well as embryonic uranium radiohaloes in coal deposits from many geological layers claimed to be hundreds of millions of years old.

These haloes represent particles of polonium and uranium, which penetrated into the coal at some point and produced a halo by radioactive decay. The fact that they are squashed indicates that part of the decay process began before the material was compressed, so the polonium had to be present before compression.

Since coal is relatively incompressible, Gentry concludes that these particles of uranium and polonium must have entered the deposit before it turned to coal.

However, there is only a very small amount of lead with the uranium; if the uranium had entered hundreds of millions of years ago, then there should be much more lead.

However, it's just hard to believe, according to conventional geological time scales, that this coal was compressed any time within the past several thousand or even hundred million years.

Some have argued that "radon that results from uranium decay is an inert gas and may have escaped, resulting in little lead being deposited. This would make the observed haloes consistent with an old age for the coal. In addition, not all of the radon would be on the surface of the particles of uranium. That which was inside or bordering on coal would likely not be able to escape. Since radon has a half-life of about 4 days, it would not have much time to escape, in any event.

What happens when something is dated as being very old, but shows little or no physical signs of relative aging? This basalt group is rather large covering an area of , square kilometers and fills a volume of , cubic kilometers.

The vast extent and sheer volume of such individual flows are orders of magnitude larger than anything ever recorded in known human history. Within this group are around individual lava flows each of rather uniform thickness over many kilometers with several extending up to kilometers from their origin. Now, the problem with the idea that these flows span a period of over 11 million years of deposition is that there is significant physical evidence that the CRBG flows were deposited relatively rapidly with respect to each other and with themselves.

The average time between each flow works out to around 36, years, but where is the erosion to the individual layers of basalt that one would expect to see after 36, years of exposure?

The very fact that these flows cover such great distances indicate that the individual flows traveled at a high rate of speed in order to avoid solidification before they covered such huge areas as they did.

Also, there are several examples where two or three different flows within the CRBG mix with each other. This suggests that some of the individual flows did not have enough time to solidify before the next flow s occurred. If some 36, years of time are supposed to separate each of the individual flows where is the evidence of erosion in the form of valleys or gullies cutting into the individual lava flows to be filled in by the next lava flow?

There are no beds of basalt boulders that would would expect to be formed over such spans of time between individual flows. However, a recent real time study by Riebe et. Over the course of 36, years this works out to between 6 to 7 meters 19 to 23 feet of vertical erosion. This is significant erosion and there should be evidence of this sort of erosion if the time gap between flow was really 36, years. So, where is this evidence?

For several other such flows in the United States and elsewhere around the world the time intervals between flows are thought to be even longer - and yet still there is little evidence of the erosion that would be expected after such passages of time.

For example, the Lincoln Porphyry of Colorado was originally thought to be a single unit because of the geographic proximity of the outcrops and the mineralogical and chemical similarities throughout the formation. Later, this idea was revised after radiometric dating placed various layers of the Lincoln Porphyry almost 30 million years apart in time. But how can such layers which show little if any evidence of interim erosion have been laid down thousands much less millions of years apart in time?

Other examples, such as the Garrawilla Lavas of New South Wales, Australia, are found between the Upper Triassic and Jurassic layers and yet these lavas, over a very large area, grade imperceptibly into lavas which overlie Lower Tertiary sedimentary rock supposedly laid down over million years later.

The Napperby depositional sequence represents the upper limit of the Gunnedah Basin sequence, with a regional unconformity existing between the Triassic and overlying Jurassic sediments of the Surat Basin north of the Liverpool Ranges.

The Gunnedah Basin sequence includes a number of basic intrusions of Mesozoic and Tertiary rocks. These are associated with massive extrusions of the Garrawilla Volcanic complex and the Liverpool, Warrumbungle and Nandewar Ranges. Also, throughout the CRBG and elsewhere are found "pillow lava" and palagonite formations - especially near the periphery of the lava flows.

There are a few outcrops where tens of meters of vertical outcrop and hundreds of meters of horizontal outcrop consist entirely of pillow structures. Also, palagonite, with a greenish-yellow appearance produced via the reaction of hot lava coming in contact with water, is found throughout. These features are suggestive of lava flow formation in a very wet or even underwater environment. Certainly pillow lavas indicate underwater deposition, but note that lavas can be extruded subaqeously without the production of pillow structures.

The potential to form pillow lava decreases as the volume of extruded lava increases. Thus, the effective contact area between lava and water where pillow formations can potentially form becomes proportionately smaller as the volume of lava extruded becomes larger. Other evidences of underwater formation include the finding of fresh water fossils such as sponge spicules, diatoms, and dinoflagellates between individual lava flows.

Consider some interesting conclusions about these findings by Barnett and Fisk in a paper published in the journal, Northwest Science: The Palouse Falls palynoflora reflects reasonably well the regional climatic conditions as evidence by the related floras of the Columbia Plateau.

The presence of planktonic forms, aquatic macrophytes, and marsh plants indicates that deposition of the sediments took place in a body of water, probably a pond or lake. This interpretation is supported by the presence of abundant diatoms. The general decrease in aquatic plants and increase in forest elements upward in the section suggest a shallowing or infilling of the pond or lake, perhaps due to increased volcanic activity and erosion of ash from the surrounding region.

Supporting this view is the presence of thin bands of lignite near the top of the section, with a cm coal layer just underlying the capping basalt. Now, what is interesting here is that these "forest elements" to include large lenses of fossilized wood are widely divergent in the type of preserved wood found. It is interesting that hundreds of species are found all mixed up together ranging from temperate birch and spruce to subtropical Eucalyptus and bald cypress.

The petrified logs have been stripped of limbs and bark and are generally found in the pillow complexes of the basaltic flows, implying that water preserved the wood from being completely destroyed by the intense heat of the lava as it buried them.

For Barnett and Fisk to suggest that the finding of such fossil remains suggest the presence of a small pond or lake being filled in by successive flows just doesn't seem to add up.

How are such ecologically divergent trees going to get concentrated around an infilling pond or lake? Also, how is a 10cm layer of coal going to be able to form under the "capping basalt"? It is supposed to take very long periods of time, great pressure, heat, and moisture to produce coal.

How did this very thin layer of coal form and then be preserved without evidence of any sort of uneven erosion by a relatively thin layer of capping basalt? Also, numerous well-rounded quartzite gravel, cobbles, and boulders locally interbedded within and above the basalt flows.

Does this make any sense? It seems more likely that huge shortly spaced watery catastrophes were involved in formation of many of these features - concentrating and transporting mats of widely divergent vegetation and inorganic rocks over long distances before they were buried by shortly spaced lava flows traveling rapidly over huge areas.

Lava traveling rapidly under water would experience rapid surface cooling and fracturing of this surface "skin". As it turns out, entablatures and colonnades are a common structural feature of basalts. These features are named by analogy to the respective horizontal and vertical architectural structures. Some have hypothesized that as water cools the outer "skin" of the molten lava a thin crust is rapidly formed.

Then, the large temperature gradient between the crust above and the molten lava below creates tensional stresses that crack the crust which allow water to percolate through these cracks to come in contact with more molten lava and form another crust, which then cracks. In the end, this rapid cyclical cooling process produces a thick slab of rock with columnar jointing.

One other evidence of fairly rapid cooling is the finding that these basalts contain relatively small crystals. When magma cools, crystals form because the solution is super-saturated with respect to some minerals.

If the magma cools quickly, the crystals do not have much time to form, so they are very small. If the magma cools slowly, then the crystals have enough time to grow and become large. For comparison, consider that some granites contain minerals which are up to one meter in diameter! The size of crystals in an igneous rock is thought to be an important indicator of the conditions where the rock formed. A rock with small crystals probably formed at or near the surface and cooled quickly.

Many other examples of paraconformities and other types of gaps in time, like these, have been described and no one seems to have a very good explanation for them.

Even as far back as , Newell, a well-known geologist noted, "The origin of paraconformities is uncertain, and I certainly do not have a simple solution to this problem. Contrary to the popular notion that geological processes are extremely slow and gradual, the geology of the Earth shows clear evidence of being dominated by relatively shortly spaced massive watery catastrophes. The idea that millions of years can be accommodated in the gaps between sedimentary layers does not stand up to critical scientific examination.

These facts are consistent with the view that our planet has had a short but dynamic history. Originally published in St.

Louis MetroVoice , Vol. Yale University, Department of Geophysics, Summer, Northwest Science, p Jonckheere and Gunther A. A problem for fission-track annealing corrections," Geophysical Research Letters , Volume 2, Issue 2, p. Krause, and Joshua J. First, that we are dealing with a closed system. And second, that no atoms of the daughter were present in the system when it formed. These assumptions furnish the most serious limitations on the accumulation clock.

Rigorously closed systems probably do not exist in nature, but surprisingly, many minerals and rocks satisfy the requirement well enough to be useful for nuclear age determination. The problem is one of judicious geologic selection. The mobility of the uranium is such that as one part of a rock formation is being improvised another part can become abnormally enriched.

Such changes can also take place at relatively low temperatures. The problem of how much lead was around to begin with still remains If all of the age-dating methods rubidium-strontium, uranium-lead and potassium-argon had yielded the same ages, the picture would be neat. The lead ages, for example, have been consistently older Isotopic ages have been obtained for material from five landing sites on the moon--those of Apollo's 11, 12, 14, 15 and Luna 16; each site has a different age.

But in a given site, the ages also vary Ideally, however, any one basaltic rock from a given site should yield the same isotopic age, regardless of the method used. And this could mean that the atomic clocks are reset during some global disaster, and events which brought the Mesozoic to a close may not be 65 million years ago but, rather, within the age and memory of man.

It therefore follows that the whole of the classical interpretation of the meteorite, lead isotope data is in doubt and that the radiometric estimates of the age of the earth are placed in jeopardy. Ages calculated from these measurements increase with sample depth up to 22 million years for lavas deduced to be recent The samples, in fact, may be very recent The discrepancies between the rejected and the accepted are arbitrarily attributed to excess or loss of argon.

Each assumption is a potential variable, the magnitude of which can seldom be ascertained. In cases where the daughter product is a gas, as in the decay of potassium K40 to the gas argon Ar 40 it is essential that none of the gas escapes from the rock over long periods of time It is obvious that radiometric technique may not be the absolute dating methods that they are claimed to be.

Age estimates on a given geological stratum by different radiometric methods are often quite different sometimes by hundreds of millions of years.

There is no absolutely reliable long-term radiological clock. The uncertainties inherent in radiometric dating are disturbing to geologists and evolutionists Porphyritic dacite, which solidified on the surface of the lava dome in , gives a whole rock K-Ar 'age ' of 0.

Mineral concentrates from the dacite, which formed in , give K-Ar 'ages 'from 0. These 'ages 'are, of course, preposterous. On the basis of the Islamic embroidered pattern and Christian ink inscription, this linen could be dated to the eleventh to twelfth centuries AD.

This corresponds to a calendar age, rounded to the nearest 5 years, of cal BC - AD 75 cal at the 68 per cent confidence level 5 where cal denotes calibrated radiocarbon dates.

Measurement procedures Because it was not known to what degree dirt, smoke or other contaminants might affect the linen samples, all three laboratories subdivided the samples, and subjected the pieces to several different mechanical and chemical cleaning procedures. All laboratories examined the textile samples microscopically to identify and remove any foreign material. Zurich precleaned the sample in an ultrasonic bath. After these initial cleaning procedures, each laboratory split the samples for further treatment.

The Arizona group split each sample into four subsamples. One pair of subsamples from each textile was treated with dilute HCL, dilute NaOH and again in acid, with rinsing in between method a. The second pair of subsamples was treated with a commercial detergent 1. The Oxford group divided the precleaned sample into three. Two of the three samples were then bleached in NaOCL 2.

The Zurich group first split each ultrasonically cleaned sample in half, with the treatment of the second set of samples being deferred until the radiocarbon measurements on the first set had been completed.

The first set of samples was further subdivided into three portions. One-third received no further treatment, one-third was submitted to a weak treatment with 0. After the first set of measurements revealed no evidence of contamination, the second set was split into two portions, to which the weak and strong chemical treatments were applied. All of the groups combusted the cleaned textile subsample with copper oxide in sealed tubes, then converted the resulting CO 2 to graphite targets.

Arizona and Oxford converted CO 2 to CO in the presence of zinc, followed by iron-catalysed reduction to graphite, as described in Slota et al. Zurich used cobalt-catalysed reduction in the presence hydrogen, as described by Vogel et al.

Each laboratory measured the graphite targets made from the textile samples, together with appropriate standards and blanks, as a group a run. Each laboratory performed between three and five independent measurements for each textile sample which were carried out over a time period of about one month.

The results of these independent measurements Table 1 in each case represent the average of several replicate measurements made during each run samples are measured sequentially, the sequence being repeated several times. The specific measurement procedures for each laboratory are given by Linick et al. Results On completion of their measurements, the laboratories forwarded their results to the British Museum Research Laboratory for statistical analysis.

The individual results as supplied by the laboratories are given in Table 1. Each date represents a unique combination of pretreatment and measurement run and applies to a separate subsample, except where indicated by the identification code.

From these data it can be seen that, for each laboratory, there are no significant differences between the results obtained with the different cleaning procedures that each used. The dipole moment of the earth's magnetic field, sunspot activity, the Suess effect, possible nearby supernova explosions, and even ocean absorption can have some effect on the carbon concentration.

However, these factors don't affect the radiocarbon dates by more than about percent, judging from the above studies. Of course, when we reach the upper limit of the method, around 40, years for the standard techniques, we should allow for much greater uncertainty as the small amounts of C remaining are much harder to measure.

Tree-ring data gives us a precise correction table for carbon dates as far back as 8,, years. The above study by Stuiver shows that the C fluctuations in the atmosphere were quite reasonable as far back as 22, years ago. The earth's magnetic field seems to have the greatest effect on C production, and there is no reason to believe that its strength was greatly different even 40, years ago.

For a refutation of Barnes' argument see Topic Therefore, atmospheric variation in C production is not a serious problem for the carbon method.

The evidence refutes Dr. Hovind's claim that the C content of our atmosphere is in the middle of a 30,year buildup. Thus, we can dismiss this young-earth argument.

It is painfully obvious that Dr. Hovind knows next to nothing about carbon dating! Changes in the sunspot cycle do have a noticeable, short-term effect on the rate of C production inasmuch as sunspots are associated with solar flares, which produce magnetic storms on Earth, and the condition of the earth's magnetic field does affect the number of cosmic rays reaching the earth's upper atmosphere. Carbon is produced by energetic collisions between cosmic rays and molecules of nitrogen in the upper atmosphere.

Sunspots have absolutely nothing to do with the rate of C decay , which defines the half-life of that radioactive element. Hovind has confused two completely different concepts. Quantum mechanics, that stout pillar of modern physics, which has been verified in so many different ways that I couldn't begin to list them all even if I had them at hand, gives us no theoretical reason for believing that the C rate of decay has changed or can be significantly affected by any reasonable process.

We also have direct observation:. That radiocarbon ages agree so closely with tree-ring counts over at least years, when the observed magnetic effect upon the production rate of C is taken into account, suggests that the decay constant itself can be assumed to be reliable. Since years is almost two half-lives for carbon, it's half-life being years plus or minus 40 years , we have excellent observational evidence that the decay rate is constant.

We also have laboratory studies which support the constancy of all the decay rates used in radiometric dating. A great many experiments have been done in attempts to change radioactive decay rates, but these experiments have invariably failed to produce any significant changes. It has been found, for example, that decay constants are the same at a temperature of degrees C or at a temperature of degrees C and are the same in a vacuum or under a pressure of several thousand atmospheres.

Measurements of decay rates under differing gravitational and magnetic fields also have yielded negative results. Although changes in alpha and beta decay rates are theoretically possible, theory also predicts that such changes would be very small [ Emery, ] and thus would not affect dating methods.

There is a fourth type of decay that can be affected by physical and chemical conditions, though only very slightly. This type of decay is electron capture e.

Because this type of decay involves a particle outside the nucleus, the decay rate may be affected by variations in the electron density near the nucleus of the atom.

For example, the decay constant of Be-7 in different beryllium chemical compounds varies by as much as 0. The only isotope of geologic interest that undergoes e. Measurements of the decay rate of K in different substances under various conditions indicate that variations in the chemical and physical environment have no detectable effect on its e.

Believe it or not, a number of creationist attacks against radiometric decay rates are aimed at a kind of "decay" called internal conversion IC , which has absolutely nothing to do with the radiometric dating methods Dalrymple, , p. Harold Slusher, a prominent member of the Institute for Creation Research, claimed that "Experiments have shown that the decay rates of cesium and iron 57 vary, hence there may be similar variations in other radioactive decay rates.

These are both stable isotopes so there is no decay rate to be changed. This statement merely reveals Slusher's ignorance of nuclear physics. Gamma decay of an excited state of iron 57 has been studied, but this has nothing to do with the kinds of decays used in radiometric dating. DeYoung [ ] lists 20 isotopes whose decay rates have been changed by environmental conditions, alluding to the possible significance of these changes to geochronology, but the only significant changes are for isotopes that "decay" by internal conversion.

These changes are irrelevant to radiometric dating methods. Keep an eye on those creationists! They will switch tracks faster than you can say "tiddlywinks. Morris claimed that free neutrons might change the decay rates. However, Henry Morris, that icon of creationism, only demonstrated that he knew no more about radiometric dating than does Dr.

Free neutrons might change one element into another, but the decay rates all remain true to their elements. Morris [ ] also suggests that neutrinos might change decay rates, citing a column by Jueneman 72 in Industrial Research.

The subtitle of Jueneman's columns, which appear regularly, is, appropriately, "Scientific Speculation. Jueneman describes a highly speculative hypothesis that would account for radioactive decay by interaction with neutrinos rather than by spontaneous decay, and he notes that an event that temporarily increased the neutrino flux might "reset" the clocks. Jueneman, however, does not propose that decay rates would be changed, nor does he state how the clocks would be reset; in addition, there is no evidence to support his speculation.

There was also an attempt by Slusher and Rybka to invoke neutrinos. Those mysterious neutrinos seem to be a hot topic! Slusher and Rybka also propose that neutrinos can change decay rates, citing an hypothesis by Dudley 40 that decay is triggered by neutrinos in a "neutrino sea" and that changes in the neutrino flux might affect decay rates.

This argument has been refuted by Brush 20 , who points out that Dudley's hypothesis not only requires rejection of both relativity and quantum mechanics, two of the most spectacularly successful theories in modern science, but is disproved by recent experiments.

Dudley himself rejects the conclusions drawn from his hypothesis by Slusher and Rybka , noting that the observed changes in decay rates are insufficient to change the age of the Earth by more than a few percent Dudley, personal communication, , quoted in 20, p.

Thus, even if Slusher and Rybka were correct--which they are not--the measured age of the Earth would still exceed 4 billion years. Dalrymple goes on to debunk several other creationists attacks on the reliability of the radiometric decay rates used in geochronology. Judging from the above, it is easy to see that creationists are indulging in wild fishing expeditions.

Compare their flighty arguments to the solid support provided by theoretical work, laboratory testing, and, for the shorter half-lives, actual observation, and add to that the statistical consistency of the dates obtained, including numerous cross-checks between different "clocks," and only one conclusion is left.

The radiometric decay rates used in dating are totally reliable. They are one of the safest bets in all of science. With at least one notable exception on the books, plants and animals get their carbon from the atmosphere. Plants take it in directly, and animals eat the plants. Thus, it gets passed up the food chain. It is not surprising, therefore, to find that the carbon in living plants and animals is in reasonable equilibrium with the atmospheric carbon Some creationists, however, have claimed that certain plants can reject carbon in favor of carbon Because of the chemical similarity of carbon and carbon, it is unlikely that such plants could deviate much from the ratio of C to C found in the atmosphere.

Neither freak cases nor small deviations pose much of a problem for radiocarbon dating, which, after all, works well with a wide variety of plant and animal species. Hence, we only have to worry about the initial concentration of C in the atmosphere. Topic R1 shows that the level of C in the atmosphere has not varied appreciably over tens of thousands of years.

Therefore, the initial C content is known for any reasonable sample! The notable exception involves certain mollusks, which get much of their carbon from dissolved limestone. Since limestone is very old it contains very little carbon Thus, in getting some of their carbon from limestone, these mollusks "inherit" some of the limestone's old age!

That is, the limestone carbon skews the normal ratio between C and C found in living things. If one dates such mollusks, one must be extra careful in interpreting the data. Not every mollusk shell presents such problems, and the dating of other material might yield a cross-check.

Further study might even allow correction tables. The discovery has strengthened the carbon method, not weakened it! By the way, shouldn't the creationist be worried over the old, carbon age of the limestone? Why is it that limestone has so little C in it? Partial contamination, say of a block of wood, may affect its different parts to different degrees. Insect burrows, cracks, and partial decay may allow contamination later on to affect those portions of the sample unequally.

However, there are laboratory techniques, often ingenious, for dealing with such problems. If the sample shows evidence of being hopelessly contaminated it is pitched.

Imsges: what is the age limit of radiocarbon dating

what is the age limit of radiocarbon dating

Puin pointed out radiocarbon dating had results scattered over a large time period, sometimes spanning a few hundred years. The water leaking out the sides of the barrel represents the loss mainly by radioactive decay of the atmosphere's supply of carbon Heavenly Art And Earthly Beauty , , op.

what is the age limit of radiocarbon dating

The ions are accelerated and passed through a stripper, which removes several electrons so that the ions emerge with a positive charge. Between those trees, which are buried in Valders red till, and an earlier, deeper layer of till, the Woodfordian gray till, lay the remains of a forest bed!

what is the age limit of radiocarbon dating

There is no absolutely reliable long-term radiological clock. Others that this technique doesn't work for the Qur'an. I decide to bury it in the back yard. Download pdf of data and commentary. Dahing aim was to make scientific sense of the Aegean and Radiocsrbon Eastern chronology from the Neolithic Age to the present. For example, a wooden object that remains in use for a lengthy period will have an apparent age greater than the actual age of the algerian dating site in which it is deposited.