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Radiocarbon Dating and the Bible Is carbon dating or radiocarbon dating always reliable and beyond question? Are all radioactive dating methods unreliable? Have carbon C 14 dates millions of years old been proven wrong? Is carbon dating useless before 2, B. Or are the above statements all false, and the truth is something else? Since there are many misconceptions about carbon dating, this paper will explain the principle, the method, some early problems with it, and its current trustworthiness. While many probably have not thought about it before, carbon dating relates to Christianity and Judaism in interesting ways.

More recently, accelerator mass spectrometry has become the method of choice; it counts all the 14 C atoms in the sample and not just the few that happen to decay during the measurements; it can therefore be used with much smaller samples as small as individual plant seedsand gives results much more quickly.

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The development of radiocarbon dating has had a profound impact on archaeology. In addition to permitting more accurate dating within archaeological sites than previous methods, it allows comparison of dates of events across great distances.

Histories of archaeology often refer to its impact as the "radiocarbon revolution". Radiocarbon dating has allowed key transitions in prehistory to be dated, such as the end of the last ice ageand the beginning of the Neolithic and Bronze Age in different regions. InMartin Kamen and Samuel Ruben of the Radiation Laboratory at Berkeley began experiments to determine if any of the elements common in organic matter had isotopes with half-lives long enough to be of value in biomedical research.

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They synthesized 14 C using the laboratory's cyclotron accelerator and soon discovered that the atom's half-life was far longer than had been previously thought.

Korffthen employed at the Franklin Institute in Philadelphiathat the interaction of thermal neutrons with 14 N in the upper atmosphere would create 14 C.

InLibby moved to the University of Chicago where he began his work on radiocarbon dating. He published a paper in in which he proposed that the carbon in living matter might include 14 C as well as non-radioactive carbon. By contrast, methane created from petroleum showed no radiocarbon activity because of its age. The results were summarized in a paper in Science inin which the authors commented that their results implied it would be possible to date materials containing carbon of organic origin.

Libby and James Arnold proceeded to test the radiocarbon dating theory by analyzing samples with known ages. For example, two samples taken from the tombs of two Egyptian kings, Zoser and Sneferuindependently dated to BC plus or minus 75 years, were dated by radiocarbon measurement to an average of BC plus or minus years.

These results were published in Science in In nature, carbon exists as two stable, nonradioactive isotopes : carbon 12 Cand carbon 13 Cand a radioactive isotope, carbon 14 Calso known as "radiocarbon". The half-life of 14 C the time it takes for half of a given amount of 14 C to decay is about 5, years, so its concentration in the atmosphere might be expected to decrease over thousands of years, but 14 C is constantly being produced in the lower stratosphere and upper troposphereprimarily by galactic cosmic raysand to a lesser degree by solar cosmic rays.

Once produced, the 14 C quickly combines with the oxygen in the atmosphere to form first carbon monoxide CO[14] and ultimately carbon dioxide CO 2.

Carbon dioxide produced in this way diffuses in the atmosphere, is dissolved in the ocean, and is taken up by plants via photosynthesis. Animals eat the plants, and ultimately the radiocarbon is distributed throughout the biosphere.

The ratio of 14 C to 12 C is approximately 1. The equation for the radioactive decay of 14 C is: [17]. During its life, a plant or animal is in equilibrium with its surroundings by exchanging carbon either with the atmosphere or through its diet.

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It will, therefore, have the same proportion of 14 C as the atmosphere, or in the case of marine animals or plants, with the ocean. Once it dies, it ceases to acquire 14 Cbut the 14 C within its biological material at that time will continue to decay, and so the ratio of 14 C to 12 C in its remains will gradually decrease.

The equation governing the decay of a radioactive isotope is: [5]. Measurement of Nthe number of 14 C atoms currently in the sample, allows the calculation of tthe age of the sample, using the equation above.

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The above calculations make several assumptions, such as that the level of 14 C in the atmosphere has remained constant over time. Calculating radiocarbon ages also requires the value of the half-life for 14 C. Radiocarbon ages are still calculated using this half-life, and are known as "Conventional Radiocarbon Age".

Since the calibration curve IntCal also reports past atmospheric 14 C concentration using this conventional age, any conventional ages calibrated against the IntCal curve will produce a correct calibrated age. When a date is quoted, the reader should be aware that if it is an uncalibrated date a term used for dates given in radiocarbon years it may differ substantially from the best estimate of the actual calendar date, both because it uses the wrong value for the half-life of 14 Cand because no correction calibration has been applied for the historical variation of 14 C in the atmosphere over time.

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Carbon is distributed throughout the atmosphere, the biosphere, and the oceans; these are referred to collectively as the carbon exchange reservoir, [32] and each component is also referred to individually as a carbon exchange reservoir. The different elements of the carbon exchange reservoir vary in how much carbon they store, and in how long it takes for the 14 C generated by cosmic rays to fully mix with them.

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This affects the ratio of 14 C to 12 C in the different reservoirs, and hence the radiocarbon ages of samples that originated in each reservoir. There are several other possible sources of error that need to be considered. The errors are of four general types:. To verify the accuracy of the method, several artefacts that were datable by other techniques were tested; the results of the testing were in reasonable agreement with the true ages of the objects.

Over time, however, discrepancies began to appear between the known chronology for the oldest Egyptian dynasties and the radiocarbon dates of Egyptian artefacts.

The question was resolved by the study of tree rings : [38] [39] [40] comparison of overlapping series of tree rings allowed the construction of a continuous sequence of tree-ring data that spanned 8, years.

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Coal and oil began to be burned in large quantities during the 19th century. Dating an object from the early 20th century hence gives an apparent date older than the true date.

For the same reason, 14 C concentrations in the neighbourhood of large cities are lower than the atmospheric average. This fossil fuel effect also known as the Suess effect, after Hans Suess, who first reported it in would only amount to a reduction of 0. A much larger effect comes from above-ground nuclear testing, which released large numbers of neutrons and created 14 C.

From about untilwhen atmospheric nuclear testing was banned, it is estimated that several tonnes of 14 C were created.

The level has since dropped, as this bomb pulse or "bomb carbon" as it is sometimes called percolates into the rest of the reservoir. Photosynthesis is the primary process by which carbon moves from the atmosphere into living things.

Oct 10,   Radiocarbon dating would be most successful if two important factors were true: that the concentration of carbon in the atmosphere had been constant for thousands of years, and that carbon moved readily through the atmosphere, biosphere, oceans and other reservoirs-in a process known as the carbon cycle. The field of radiocarbon dating has become a technical one far removed from the naive simplicity which characterized its initial introduction by Libby in the late 's. It is, therefore, not surprising that many misconceptions about what radiocarbon can or cannot do and what it has or has not shown are prevalent among creationists and evolutionists - lay people as well as scientists not. More information on Dead Sea scroll dating can be found in the journal Radiocarbon vol.3 Carbon dating has verified hundreds of archaeological sites mentioned in the Bible. Over 57, readable clay tablets in Mesopotamia and many Egyptian Papyrii have shown that even many slaves could write in Abraham's time.

In photosynthetic pathways 12 C is absorbed slightly more easily than 13 Cwhich in turn is more easily absorbed than 14 C. This effect is known as isotopic fractionation.

At higher temperatures, CO 2 has poor solubility in water, which means there is less CO 2 available for the photosynthetic reactions. The enrichment of bone 13 C also implies that excreted material is depleted in 13 C relative to the diet.

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The carbon exchange between atmospheric CO 2 and carbonate at the ocean surface is also subject to fractionation, with 14 C in the atmosphere more likely than 12 C to dissolve in the ocean. This increase in 14 C concentration almost exactly cancels out the decrease caused by the upwelling of water containing old, and hence 14 C depleted, carbon from the deep ocean, so that direct measurements of 14 C radiation are similar to measurements for the rest of the biosphere.

Correcting for isotopic fractionation, as is done for all radiocarbon dates to allow comparison between results from different parts of the biosphere, gives an apparent age of about years for ocean surface water. The marine effect : The CO 2 in the atmosphere transfers to the ocean by dissolving in the surface water as carbonate and bicarbonate ions; at the same time the carbonate ions in the water are returning to the air as CO 2. The deepest parts of the ocean mix very slowly with the surface waters, and the mixing is uneven.

The main mechanism that brings deep water to the surface is upwelling, which is more common in regions closer to the equator.

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Upwelling is also influenced by factors such as the topography of the local ocean bottom and coastlines, the climate, and wind patterns. Overall, the mixing of deep and surface waters takes far longer than the mixing of atmospheric CO 2 with the surface waters, and as a result water from some deep ocean areas has an apparent radiocarbon age of several thousand years. Upwelling mixes this "old" water with the surface water, giving the surface water an apparent age of about several hundred years after correcting for fractionation.

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The northern and southern hemispheres have atmospheric circulation systems that are sufficiently independent of each other that there is a noticeable time lag in mixing between the two. Since the surface ocean is depleted in 14 C because of the marine effect, 14 C is removed from the southern atmosphere more quickly than in the north.

For example, rivers that pass over limestonewhich is mostly composed of calcium carbonatewill acquire carbonate ions. Similarly, groundwater can contain carbon derived from the rocks through which it has passed.

Volcanic eruptions eject large amounts of carbon into the air. Dormant volcanoes can also emit aged carbon. Any addition of carbon to a sample of a different age will cause the measured date to be inaccurate. Contamination with modern carbon causes a sample to appear to be younger than it really is: the effect is greater for older samples. Samples for dating need to be converted into a form suitable for measuring the 14 C content; this can mean conversion to gaseous, liquid, or solid form, depending on the measurement technique to be used.

Before this can be done, the sample must be treated to remove any contamination and any unwanted constituents. Particularly for older samples, it may be useful to enrich the amount of 14 C in the sample before testing. This can be done with a thermal diffusion column. Once contamination has been removed, samples must be converted to a form suitable for the measuring technology to be used. For accelerator mass spectrometrysolid graphite targets are the most common, although gaseous CO 2 can also be used.

In addition to radiocarbon dating, we are also experimenting with luminescence dating. This method measures the last time sediments within the clam garden terrace, or on the old beach below the garden, were exposed to sunlight. Based on our dating thus far, some clam gardens are at least 2, years old. Nov 03,   Four widely used age-depth modelling routines - CLAM, OxCal, Bacon and Bchron - were tested using radiocarbon dates simulated from varved sediment stratigraphies. All methods produce mean age-depth models that are close to the true varve age, but the uncertainty estimation differs considerably among models. There are two source or reservoir effects relevant to the radiocarbon dating of shells-the marine effect and the hard water effect. Age offset evaluation must be done on radiocarbon dating results on shells because of these effects. The marine effect is a consequence of the slow mixing between surface waters and deep waters in the oceans.

The quantity of material needed for testing depends on the sample type and the technology being used. There are two types of testing technology: detectors that record radioactivity, known as beta counters, and accelerator mass spectrometers. For beta counters, a sample weighing at least 10 grams 0.

For decades after Libby performed the first radiocarbon dating experiments, the only way to measure the 14 C in a sample was to detect the radioactive decay of individual carbon atoms. Libby's first detector was a Geiger counter of his own design. He converted the carbon in his sample to lamp black soot and coated the inner surface of a cylinder with it.

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This cylinder was inserted into the counter in such a way that the counting wire was inside the sample cylinder, in order that there should be no material between the sample and the wire. Libby's method was soon superseded by gas proportional counterswhich were less affected by bomb carbon the additional 14 C created by nuclear weapons testing.

These counters record bursts of ionization caused by the beta particles emitted by the decaying 14 C atoms; the bursts are proportional to the energy of the particle, so other sources of ionization, such as background radiation, can be identified and ignored. The counters are surrounded by lead or steel shielding, to eliminate background radiation and to reduce the incidence of cosmic rays.

In addition, anticoincidence detectors are used; these record events outside the counter and any event recorded simultaneously both inside and outside the counter is regarded as an extraneous event and ignored.

The other common technology used for measuring 14 C activity is liquid scintillation counting, which was invented inbut which had to wait until the early s, when efficient methods of benzene synthesis were developed, to become competitive with gas counting; after liquid counters became the more common technology choice for newly constructed dating laboratories.

The counters work by detecting flashes of light caused by the beta particles emitted by 14 C as they interact with a fluorescing agent added to the benzene.

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Like gas counters, liquid scintillation counters require shielding and anticoincidence counters. For both the gas proportional counter and liquid scintillation counter, what is measured is the number of beta particles detected in a given time period.

You can also provide an alternative curve which must be present within the folder specified by ccdir, e.

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Negative radiocarbon ages are calibrated with one of the postbomb curves from Hua et al. Three postbomb curves are provided for different regions of the northern hemisphere check the map of Hua et al. Clam will provide a warning if no such option is provided with negative radiocarbon ages. The clam functions to calibrate 14 C dates are similar to that of standard calibration approaches such as used in Calib Stuiver and Reimer, or OxCal Bronk Ramsey, Therefore, just like OxCal Bronk Ramsey, clam does not calculate directly on the 14 C scale, but instead first converts all 14 C ages to their fractions, F14C Reimer et al.

As an example, check the result of calibrate By default, the dates are calibrated assuming a Gaussian distribution. However, as discussed by Christen and Perezsince the reported errors of radiocarbon dates are estimates of the true error only, this error could be under- or over-estimated. Therefore, instead of using just a single value for the error, Christen and Perez propose to use a distribution for the error size. This student-t distribution has two parameters, a and b, and to maintain symmetry, a should always equal b For student-t calibration, provide two parameters instead, e.

This will result in distributions very similar to those using the default Gaussian, but with longer tails. Try the clam function student.

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Equivalent radiocarbon ages can be calculated using the function pMC. Similarly, 14 C ages can be turned into pMC using, for example, age. In some cases, there's a need to mix calibration curves. To do so, use mix. In case of a regional marine reservoir effect see the Marine Reservoir Correction databaseprovide its average and error as, e. A graph of the raw and calibrated date will be drawn, and the calibrated ranges will be printed. To calibrate a different date, provide its mean and error as follows: calibrate mean, errore.

As this date will fall partly beyond the younger extreme of the calibration curve, a warning will be given similar warnings will be given for too old dates. Let's look at assumption 1 again.

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Libby, who won a Nobel Prize in for C 14 dating, failed to question his uniformitarian assumption, that the ratio had reached static equilibrium. This was the state of affairs with radiocarbon dating for many years.

To "face up" to the absolute age problem, scientists devised calibration scales based on tree rings, lake varves, and ice cores. Oak trees can live for years, and they grow a new tree ring every year. The ring is thick when the winter is short, and thin when the winter is long. Different trees growing at the same time in the same forest have very similar tree ring patterns.

So, by comparing many different trees in a forest in South Germany, and performing radiocarbon dating on a large number of samples, a calibration scale was developed.

Other researchers did similar work in a forest in Northern Germany. Still others did this in Ireland, and others in England.

Feb 27,   But new research using radiocarbon dating and analyses of ancient landscapes reveals that these rock walls are the remnants of a technology at least 3, years old-evidence of an aquaculture system known as clam gardens that once helped feed a much larger population of coastal Indigenous peoples.

Finally American researchers did this with bristlecone pine trees in Arizona. Bristlecone pine is both worse and better to use than oak.

It is better in that an individual bristlecone pine can live for 2, years. Ralph et al. Of course, they could all be wrong, but if enough independent studies agree with each other, then being wrong becomes a more remote possibility. In addition to tree rings, scientists have looked at what are called lake varves in Northern Sweden.

Dating - the Radiocarbon Way

Now trees shed their leaves in the fall, and the leaves that fall in a lake form a thin layer at the bottom. This happens annually, and thus very thin annual layers are deposited.

By counting lake varves, one has a cross-check for carbon dating similar to tree rings. A third cross-check is ice cores in Greenland.

More snow is deposited in summer, when the air is wetter, than in winter. Thus there are annual rings in Greenland ice cores too. However, instead of dating organic matter, carbon dating is performed on the minute amounts of carbon dioxide and methane gas in each layer. So, because of the triple testimony of tree rings, lake varves, and ice cores, carbon dating works assuming: 1.

We can measure the ratio very accurately. We know the ways an organism's ratio is altered. C, 11, B. C, and more than 15, B. Carbon relates to Christianity and Judaism in four ways.



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