Carbon dating methods accurate

Carbon dating methods accurate

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Is Carbon Dating Reliable?

Radiocarbon dating can easily establish that humans have been on the earth for over twenty thousand years, at least twice as long as creationists are willing to allow. Therefore it should come as no surprise that creationists at the Institute for Creation Research ICR have been trying desperately to discredit this method for years. They have their work cut out for them, however, because radiocarbon C dating is one of the most reliable of all the radiometric dating methods.

This article will answer several of the most common creationist attacks on carbon dating, using the question-answer format that has proved so useful to lecturers and debaters. Cosmic rays in the upper atmosphere are constantly converting the isotope nitrogen N into carbon C or radiocarbon. Living organisms are constantly incorporating this C into their bodies along with other carbon isotopes. When the organisms die, they stop incorporating new C, and the old C starts to decay back into N by emitting beta particles.

The older an organism's remains are, the less beta radiation it emits because its C is steadily dwindling at a predictable rate. So, if we measure the rate of beta decay in an organic sample, we can calculate how old the sample is. C decays with a half-life of 5, years. Kieth and Anderson radiocarbon-dated the shell of a living freshwater mussel and obtained an age of over two thousand years. ICR creationists claim that this discredits C dating.

How do you reply? It does discredit the C dating of freshwater mussels, but that's about all. Kieth and Anderson show considerable evidence that the mussels acquired much of their carbon from the limestone of the waters they lived in and from some very old humus as well. Carbon from these sources is very low in C because these sources are so old and have not been mixed with fresh carbon from.

Thus, a freshly killed mussel has far less C than a freshly killed something else, which is why the C dating method makes freshwater mussels seem older than they really are. When dating wood there is no such problem because wood gets its carbon straight from the air, complete with a full dose of C The creationists who quote Kieth and Anderson never tell you this, however.

A sample that is more than fifty thousand years old shouldn't have any measurable C Coal, oil, and natural gas are supposed to be millions of years old; yet creationists say that some of them contain measurable amounts of C, enough to give them C ages in the tens of thousands of years. How do you explain this? Very simply. Radiocarbon dating doesn't work well on objects much older than twenty thousand years, because such objects have so little C left that their beta radiation is swamped out by the background radiation of cosmic rays and potassium K decay.

Younger objects can easily be dated, because they still emit plenty of beta radiation, enough to be measured after the background radiation has been subtracted out of the total beta radiation. However, in either case, the background beta radiation has to be compensated for, and, in the older objects, the amount of C they have left is less than the margin of error in measuring background radiation.

As Hurley points out:. Without rather special developmental work, it is not generally practicable to measure ages in excess of about twenty thousand years, because the radioactivity of the carbon becomes so slight that it is difficult to get an accurate measurement above background radiation. Cosmic rays form beta radiation all the time; this is the radiation that turns N to C in the first place.

K decay also forms plenty of beta radiation. Stearns, Carroll, and Clark point out that ". This radiation cannot be totally eliminated from the laboratory, so one could probably get a "radiocarbon" date of fifty thousand years from a pure carbon-free piece of tin. However, you now know why this fact doesn't at all invalidate radiocarbon dates of objects younger than twenty thousand years and is certainly no evidence for the notion that coals and oils might be no older than fifty thousand years.

Creationists such as Cook claim that cosmic radiation is now forming C in the atmosphere about one and one-third times faster than it is decaying. If we extrapolate backwards in time with the proper equations, we find that the earlier the historical period, the less C the atmosphere had. If we extrapolate. If they are right, this means all C ages greater than two or three thousand years need to be lowered drastically and that the earth can be no older than ten thousand years. Yes, Cook is right that C is forming today faster than it's decaying.

However, the amount of C has not been rising steadily as Cook maintains; instead, it has fluctuated up and down over the past ten thousand years. How do we know this? From radiocarbon dates taken from bristlecone pines. There are two ways of dating wood from bristlecone pines: Since the tree ring counts have reliably dated some specimens of wood all the way back to BC, one can check out the C dates against the tree-ring-count dates.

Admittedly, this old wood comes from trees that have been dead for hundreds of years, but you don't have to have an 8,year-old bristlecone pine tree alive today to validly determine that sort of date. It is easy to correlate the inner rings of a younger living tree with the outer rings of an older dead tree. The correlation is possible because, in the Southwest region of the United States, the widths of tree rings vary from year to year with the rainfall, and trees all over the Southwest have the same pattern of variations.

When experts compare the tree-ring dates with the C dates, they find that radiocarbon ages before BC are really too young—not too old as Cook maintains. For example, pieces of wood that date at about BC by tree-ring counts date at only BC by regular C dating and BC by Cook's creationist revision of C dating as we see in the article, "Dating, Relative and Absolute," in the Encyclopaedia Britannica.

So, despite creationist claims, C before three thousand years ago was decaying faster than it was being formed and C dating errs on the side of making objects from before BC look too young , not too old. But don't trees sometimes produce more than one growth ring per year? Wouldn't that spoil the tree-ring count? If anything, the tree-ring sequence suffers far more from missing rings than from double rings. This means that the tree-ring dates would be slightly too young, not too old.

Of course, some species of tree tend to produce two or more growth rings per year. But other species produce scarcely any extra rings. Most of the tree-ring sequence is based on the bristlecone pine. This tree rarely produces even a trace of an extra ring; on the contrary, a typical bristlecone pine has up to 5 percent of its rings missing. Concerning the sequence of rings derived from the bristlecone pine, Ferguson says:.

In 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. In the growth-ring analyses of approximately one thousand trees in the White Mountains, we have, in fact, found no more than three or four occurrences of even incipient multiple growth layers.

In years of severe drought, a bristlecone pine may fail to grow a complete ring all the way around its perimeter; we may find the ring if we bore into the tree from one angle, but not from another. Hence at least some of the missing rings can be found. Even so, the missing rings are a far more serious problem than any double rings. Other species of trees corroborate the work that Ferguson did with bristlecone pines. Before his work, the tree-ring sequence of the sequoias had been worked out back to BC.

The archaeological ring sequence had been worked out back to 59 BC. The limber pine sequence had been worked out back to 25 BC. The radiocarbon dates and tree-ring dates of these other trees agree with those Ferguson got from the bristlecone pine. But even if he had had no other trees with which to work except the bristlecone pines, that evidence alone would have allowed him to determine the tree-ring chronology back to BC.

See Renfrew for more details. So, creationists who complain about double rings in their attempts to disprove C dating are actually grasping at straws. If the Flood of Noah occurred around BC, as some creationists claim, then all the bristlecone pines would have to be less than five thousand years old. This would mean that eighty-two hundred years worth of tree rings had to form in five thousand years, which would mean that one-third of all the bristlecone pine rings would have to be extra rings.

Creationists are forced into accepting such outlandish conclusions as these in order to jam the facts of nature into the time frame upon which their "scientific" creation model is based. Creationist Thomas G. Barnes has claimed that the earth's magnetic field is decaying exponentially with a half-life of fourteen hundred years. Not only does he consider this proof that the earth can be no older than ten thousand years but he also points out that a greater magnetic strength in the past would reduce C dates.

Now if the magnetic field several thousand years ago was indeed many times stronger than it is today, there would have been less cosmic radiation entering the atmosphere back then and less C would have been produced. Therefore, any C dates taken from objects of that time period would be too high. How do you answer him?

Like Cook, Barnes looks at only part of the evidence. What he ignores is the great body of archaeological and geological data showing that the strength of the magnetic field has been fluctuating up and down for thousands of years and that it has reversed polarity many times in the geological past. So, when Barnes extrapolates ten thousand years into the past, he concludes that the magnetic field was nineteen times stronger in BC than it is today, when, actually, it was only half as intense then as now.

This means that radiocarbon ages of objects from that time period will be too young, just as we saw from the bristlecone pine evidence. But how does one know that the magnetic field has fluctuated and reversed polarity? Aren't these just excuses scientists give in order to neutralize Barnes's claims? The evidence for fluctuations and reversals of the magnetic field is quite solid. Bucha, a Czech geophysicist, has used archaeological artifacts made of baked clay to determine the strength of the earth's magnetic field when they were manufactured.

He found that the earth's magnetic field was 1. See Bailey, Renfrew, and Encyclopedia Britannica for details. In other words, it rose in intensity from 0. Even before the bristlecone pine calibration of C dating was worked out by Ferguson, Bucha predicted that this change in the magnetic field would make radiocarbon dates too young. This idea [that the fluctuating magnetic field affects influx of cosmic rays, which in turn affects C formation rates] has been taken up by the Czech geophysicist, V.

Bucha, who has been able to determine, using samples of baked clay from archeological sites, what the intensity of the earth's magnetic field was at the time in question. Even before the tree-ring calibration data were available to them, he and the archeologist, Evzen Neustupny, were able to suggest how much this would affect the radiocarbon dates.

Renfrew, p. There is a good correlation between the strength of the earth's magnetic field as determined by Bucha and the deviation of the atmospheric radiocarbon concentration from its normal value as indicated by the tree-ring radiocarbon work. As for the question of polarity reversals, plate tectonics can teach us much. It is a fact that new oceanic crust continually forms at the mid-oceanic ridges and spreads away from those ridges in opposite directions.

However, a little more knowledge about the exact ins and outs of carbon dating reveals that perhaps it is not quite as fool-proof a process as we. Older fossils cannot be dated by carbon methods and require radiometric dating The strict rules of the scientific method ensure the accuracy of fossil dating.

Jump to navigation. I asked several people who know about this field. Their responses are numbered below. C14 dating is very accurate for wood used up to about 4, years ago. This is only because it is well calibrated with objects of known age.

For decades, radiocarbon dating has been a way for scientists to get a rough picture of when once-living stuff lived. The method has been revolutionary and remains one of the most commonly used dating methods to study the past.

How accurate are carbon-dating methods? All methods of radioactive dating rely on three assumptions that may not necessarily be true:. It is assumed that the rate of decay has remained constant over time.

Radiometric Dating — Is It Accurate?

Radiocarbon dating also referred to as carbon dating or carbon dating is a method for determining the age of an object containing organic material by using the properties of radiocarbon , a radioactive isotope of carbon. The method was developed in the late s by Willard Libby , who received the Nobel Prize in Chemistry for his work in It is based on the fact that radiocarbon 14 C is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting 14 C combines with atmospheric oxygen to form radioactive carbon dioxide , which is incorporated into plants by photosynthesis ; animals then acquire 14 C by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14 C it contains begins to decrease as the 14 C undergoes radioactive decay. Measuring the amount of 14 C in a sample from a dead plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died.

ERRORS ARE FEARED IN CARBON DATING

Carbon dating is used to determine the age of biological artifacts up to 50, years old. This technique is widely used on recent artifacts, but educators and students alike should note that this technique will not work on older fossils like those of the dinosaurs alleged to be millions of years old. This technique is not restricted to bones; it can also be used on cloth, wood and plant fibers. Carbon dating has been used successfully on the Dead Sea Scrolls, Minoan ruins and tombs of the pharaohs among other things. Carbon is a radioactive isotope of carbon. The half-life of carbon is approximately 5, years. The short half-life of carbon means it cannot be used to date fossils that are allegedly extremely old, e. The question should be whether or not carbon can be used to date any artifacts at all? The answer is not simple.

Smith is known as the Father of English Geology.

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Is Carbon Dating Accurate?

To preserve these articles as they originally appeared, The Times does not alter, edit or update them. Occasionally the digitization process introduces transcription errors or other problems. Since , scientists have reckoned the ages of many old objects by measuring the amounts of radioactive carbon they contain. New research shows, however, that some estimates based on carbon may have erred by thousands of years. It is too soon to know whether the discovery will seriously upset the estimated dates of events like the arrival of human beings in the Western Hemisphere, scientists said. But it is already clear that the carbon method of dating will have to be recalibrated and corrected in some cases. 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. In some cases, the latter ratio appears to be a much more accurate gauge of age than the customary method of carbon dating, the scientists said. In principle, any material of plant or animal origin, including textiles, wood, bones and leather, can be dated by its content of carbon 14, a radioactive form of carbon in the environment that is incorporated by all living things. Because it is radioactive, carbon 14 steadily decays into other substances.

Thanks to Fossil Fuels, Carbon Dating Is in Jeopardy. One Scientist May Have an Easy Fix

It is an accurate way to date specific geologic events. This is an enormous branch of geochemistry called Geochronology. There are many radiometric clocks and when applied to appropriate materials, the dating can be very accurate. As one example, the first minerals to crystallize condense from the hot cloud of gasses that surrounded the Sun as it first became a star have been dated to plus or minus 2 million years!! That is pretty accurate!!!

Yes, I want to follow Jesus. I am a follower of Jesus. I still have questions. Is Carbon Dating Accurate? Is carbon dating accurate? Only to a certain extent.

Radiometric dating is a much misunderstood phenomenon. Evolutionists often misunderstand the method, assuming it gives a definite age for tested samples. Creationists also often misunderstand it, claiming that the process is inaccurate. Perhaps a good place to start this article would be to affirm that radiometric dating is not inaccurate. It is certainly incorrect, and it is certainly based on wrong assumptions, but it is not inaccurate. What do I mean?

Radiocarbon dating can easily establish that humans have been on the earth for over twenty thousand years, at least twice as long as creationists are willing to allow. Therefore it should come as no surprise that creationists at the Institute for Creation Research ICR have been trying desperately to discredit this method for years. They have their work cut out for them, however, because radiocarbon C dating is one of the most reliable of all the radiometric dating methods. This article will answer several of the most common creationist attacks on carbon dating, using the question-answer format that has proved so useful to lecturers and debaters. Cosmic rays in the upper atmosphere are constantly converting the isotope nitrogen N into carbon C or radiocarbon. Living organisms are constantly incorporating this C into their bodies along with other carbon isotopes. When the organisms die, they stop incorporating new C, and the old C starts to decay back into N by emitting beta particles.

Many people think that radiometric dating has proved the Earth is millions of years old. Even the way dates are reported e. However, although we can measure many things about a rock, we cannot directly measure its age. For example, we can measure its mass, its volume, its colour, the minerals in it, their size and the way they are arranged. We can crush the rock and measure its chemical composition and the radioactive elements it contains. But we do not have an instrument that directly measures age. Before we can calculate the age of a rock from its measured chemical composition, we must assume what radioactive elements were in the rock when it formed.

How accurate is radiocarbon dating?
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