How accurate are Carbon and other radioactive dating methods? • n3ws.info
We know it is accurate because radiometric dating is based on the radioactive decay of unstable isotopes. For example, the element Uranium exists as one of. Radiometric dating or radioactive dating is a technique used to date materials such as rocks or . In uranium–lead dating, the concordia diagram is used which also Accurate radiometric dating generally requires that the parent has a long .. This in turn corresponds to a difference in age of closure in the early solar system. While the uranium-lead dating method was limited (being only applicable to it was proved to scientists that radioactive dating was both possible and reliable. The difference between the concentration of carbon–14 in the material to be.
Some nuclides are inherently unstable. That is, at some point in time, an atom of such a nuclide will undergo radioactive decay and spontaneously transform into a different nuclide. This transformation may be accomplished in a number of different ways, including alpha decay emission of alpha particles and beta decay electron emission, positron emission, or electron capture.
Another possibility is spontaneous fission into two or more nuclides. While the moment in time at which a particular nucleus decays is unpredictable, a collection of atoms of a radioactive nuclide decays exponentially at a rate described by a parameter known as the half-lifeusually given in units of years when discussing dating techniques. After one half-life has elapsed, one half of the atoms of the nuclide in question will have decayed into a "daughter" nuclide or decay product.
In many cases, the daughter nuclide itself is radioactive, resulting in a decay chaineventually ending with the formation of a stable nonradioactive daughter nuclide; each step in such a chain is characterized by a distinct half-life. In these cases, usually the half-life of interest in radiometric dating is the longest one in the chain, which is the rate-limiting factor in the ultimate transformation of the radioactive nuclide into its stable daughter.
Isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years e. It is not affected by external factors such as temperaturepressurechemical environment, or presence of a magnetic or electric field. For all other nuclides, the proportion of the original nuclide to its decay products changes in a predictable way as the original nuclide decays over time.
This predictability allows the relative abundances of related nuclides to be used as a clock to measure the time from the incorporation of the original nuclides into a material to the present.
Accuracy of radiometric dating[ edit ] Thermal ionization mass spectrometer used in radiometric dating.
The basic equation of radiometric dating requires that neither the parent nuclide nor the daughter product can enter or leave the material after its formation. The possible confounding effects of contamination of parent and daughter isotopes have to be considered, as do the effects of any loss or gain of such isotopes since the sample was created. It is therefore essential to have as much information as possible about the material being dated and to check for possible signs of alteration.
Alternatively, if several different minerals can be dated from the same sample and are assumed to be formed by the same event and were in equilibrium with the reservoir when they formed, they should form an isochron. This can reduce the problem of contamination. In uranium—lead datingthe concordia diagram is used which also decreases the problem of nuclide loss.
Finally, correlation between different isotopic dating methods may be required to confirm the age of a sample. For example, the age of the Amitsoq gneisses from western Greenland was determined to be 3. The procedures used to isolate and analyze the parent and daughter nuclides must be precise and accurate. This normally involves isotope-ratio mass spectrometry.
For instance, carbon has a half-life of 5, years. After an organism has been dead for 60, years, so little carbon is left that accurate dating cannot be established. On the other hand, the concentration of carbon falls off so steeply that the age of relatively young remains can be determined precisely to within a few decades.
Closure temperature If a material that selectively rejects the daughter nuclide is heated, any daughter nuclides that have been accumulated over time will be lost through diffusionsetting the isotopic "clock" to zero. The temperature at which this happens is known as the closure temperature or blocking temperature and is specific to a particular material and isotopic system. These temperatures are experimentally determined in the lab by artificially resetting sample minerals using a high-temperature furnace.
As the mineral cools, the crystal structure begins to form and diffusion of isotopes is less easy. At a certain temperature, the crystal structure has formed sufficiently to prevent diffusion of isotopes.
This temperature is what is known as closure temperature and represents the temperature below which the mineral is a closed system to isotopes. Thus an igneous or metamorphic rock or melt, which is slowly cooling, does not begin to exhibit measurable radioactive decay until it cools below the closure temperature.
The age that can be calculated by radiometric dating is thus the time at which the rock or mineral cooled to closure temperature. This field is known as thermochronology or thermochronometry. The age is calculated from the slope of the isochron line and the original composition from the intercept of the isochron with the y-axis. The equation is most conveniently expressed in terms of the measured quantity N t rather than the constant initial value No.
The above equation makes use of information on the composition of parent and daughter isotopes at the time the material being tested cooled below its closure temperature. This is well-established for most isotopic systems. Plotting an isochron is used to solve the age equation graphically and calculate the age of the sample and the original composition. Modern dating methods[ edit ] Radiometric dating has been carried out since when it was invented by Ernest Rutherford as a method by which one might determine the age of the Earth.
In the century since then the techniques have been greatly improved and expanded. The mass spectrometer was invented in the s and began to be used in radiometric dating in the s.
It operates by generating a beam of ionized atoms from the sample under test. The ions then travel through a magnetic field, which diverts them into different sampling sensors, known as " Faraday cups ", depending on their mass and level of ionization.
On impact in the cups, the ions set up a very weak current that can be measured to determine the rate of impacts and the relative concentrations of different atoms in the beams. Uranium—lead dating method[ edit ] Main article: Uranium—lead dating A concordia diagram as used in uranium—lead datingwith data from the Pfunze BeltZimbabwe. This scheme has been refined to the point that the error margin in dates of rocks can be as low as less than two million years in two-and-a-half billion years.
Zircon has a very high closure temperature, is resistant to mechanical weathering and is very chemically inert. Zircon also forms multiple crystal layers during metamorphic events, which each may record an isotopic age of the event. This can be seen in the concordia diagram, where the samples plot along an errorchron straight line which intersects the concordia curve at the age of the sample.
Samarium—neodymium dating method[ edit ] Main article: Samarium—neodymium dating This involves the alpha decay of Sm to Nd with a half-life of 1. It is very much driven by the existing long-age world view that pervades academia today. Various other attempts were made to date the volcanic rocks in the area. Over the years an age of 2.
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After this was widely accepted, further studies of the rocks brought the radiometric age down to about 1. Such is the dating game. Are we suggesting that evolutionists are conspiring to massage the data to get what they want? It is simply that all observations must fit the prevailing paradigm. We must remember that the past is not open to the normal processes of experimental science, that is, repeatable experiments in the present. A scientist cannot do experiments on events that happened in the past.
Scientists do not measure the age of rocks, they measure isotope concentrations, and these can be measured extremely accurately. Those involved with unrecorded history gather information in the present and construct stories about the past. The level of proof demanded for such stories seems to be much less than for studies in the empirical sciences, such as physics, chemistry, molecular biology, physiology, etc.
Williams, an expert in the environmental fate of radioactive elements, identified 17 flaws in the isotope dating reported in just three widely respected seminal papers that supposedly established the age of the Earth at 4.
What date would you like? The forms issued by radioisotope laboratories for submission with samples to be dated commonly ask how old the sample is expected to be. If the techniques were absolutely objective and reliable, such information would not be necessary. Testing radiometric dating methods If the long-age dating techniques were really objective means of finding the ages of rocks, they should work in situations where we know the age.
Furthermore, different techniques should consistently agree with one another. The secular scientific literature lists many examples of excess argon causing dates of millions of years in rocks of known historical age. This is consistent with a young world—the argon has had too little time to escape.
So data are again selected according to what the researcher already believes about the age of the rock. Steve Austin sampled basalt from the base of the Grand Canyon strata and from the lava that spilled over the edge of the canyon. By evolutionary reckoning, the latter should be a billion years younger than the basalt from the bottom. Standard laboratories analyzed the isotopes. The rubidium-strontium isochron technique suggested that the recent lava flow was Ma older than the basalts beneath the Grand Canyon—an impossibility.
Different dating techniques should consistently agree If the dating methods are an objective and reliable means of determining ages, they should agree. If a chemist were measuring the sugar content of blood, all valid methods for the determination would give the same answer within the limits of experimental error.
However, with radiometric dating, the different techniques often give quite different results. In the study of the Grand Canyon rocks by Austin, different techniques gave different results. Techniques that give results that can be dismissed just because they don't agree with what we already believe cannot be considered objective.
In Australia, some wood found the Tertiary basalt was clearly buried in the lava flow that formed the basalt, as can be seen from the charring. The latter figures are significant because thorium-derived dates should be the more reliable, since thorium is less mobile than the uranium minerals that are the parents of the lead isotopes in lead-lead system.
More evidence something is wrong— 14C in fossils supposedly millions of years old Carbon Dating in many cases seriously embarrasses evolutionists by giving ages that are much younger than those expected from their model of early history.
A specimen older than 50, years should have too little 14C to measure. Laboratories that measure 14C would like a source of organic material with zero 14C to use as a blank to check that their lab procedures do not add 14C. Coal is an obvious candidate because the youngest coal is supposed to be millions of years old, and most of it is supposed to be tens or hundreds of millions of years old. Such old coal should be devoid of 14C. No source of coal has been found that completely lacks 14C.
It is an unsolved mystery to evolutionists as to why coal has 14C in it, or wood supposedly millions of years old still has 14C present, but it makes perfect sense in a creationist world view. A few of them follow. Evidence for a rapid formation of geological strata, as in the biblical flood. Some of the evidences are: For more, see books by geologists Morris  and Austin.
But these could not last more than a few thousand years—certainly not the 65 Ma since the last dinosaurs lived, according to evolutionists. Rapid reversals during the flood year and fluctuations shortly after would have caused the field energy to drop even faster. This helium originally escaped from rocks. This happens quite fast, yet so much helium is still in some rocks that it has not had time to escape—certainly not billions of years.
The supernova remnants SNRs should keep expanding for hundreds of thousands of years, according to physical equations. Yet there are no very old, widely expanded Stage 3 SNRs, and few moderately old Stage 1 ones in our galaxy, the Milky Way, or in its satellite galaxies, the Magellanic Clouds.
But even if the moon had started receding from being in contact with the Earth, it would have taken only 1. This gives a maximum age of the moon, not the actual age. This is far too young for evolutionists who claim the moon is 4. The sea is not nearly salty enough for this to have been happening for billions of years.
Even granting generous assumptions to evolutionists, the sea could not be more than 62 Ma years old—far younger than the billions of years believed by the evolutionists. Again, this indicates a maximum age, not the actual age. Russell Humphreys gives other processes inconsistent with billions of years in the pamphlet Evidence for a Young World.
They realize that all science is tentative because we do not have all the data, especially when dealing with the past. The atheistic evolutionist W. In reality, all dating methods, including those that point to a young Earth, rely on unprovable assumptions. Creationists ultimately date the Earth historically using the chronology of the Bible. This is because they believe that this is an accurate eyewitness account of world history, which bears the evidence within it that it is the Word of Godand therefore totally reliable and error-free.
What the do the radiometric dates of millions of years mean, if they are not true ages? To answer this question, it is necessary to scrutinize further the experimental results from the various dating techniques, the interpretations made on the basis of the results and the assumptions underlying those interpretations.
The isochron dating technique was thought to be infallible because it supposedly covered the assumptions about starting conditions and closed systems. This problem cannot be overlooked, especially in evaluating the numerical time scale. Similar questions can also arise in applying Sm-Nd [samarium-neodymium] and U-Pb [uranium-lead] isochron methods.Carbon Dating Flaws
Another currently popular dating method is the uranium-lead concordia technique. This effectively combines the two uranium-lead decay series into one diagram. Numerous models, or stories, have been developed to explain such data.
Again, the stories are evaluated according to their own success in agreeing with the existing long ages belief system. Andrew Snelling has suggested that fractionation sorting of elements in the molten state in the Earth's mantle could be a significant factor in explaining the ratios of isotope concentrations which are interpreted as ages.
As long ago asNobel Prize nominee Melvin Cookprofessor of metallurgy at the University of Utah, pointed out evidence that lead isotope ratios, for example, may involve alteration by important factors other than radioactive decay. Thorium has a long half-life decays very slowly and is not easily moved out of the rock, so if the lead came from thorium decay, some thorium should still be there. The concentrations of lead, lead, and lead suggest that the lead came about by neutron capture conversion of lead to lead to lead When the isotope concentrations are adjusted for such conversions, the ages calculated are reduced from some Ma to recent.
Other ore bodies seemed to show similar evidence. Cook recognized that the current understanding of nuclear physics did not seem to allow for such a conversion under normal conditions, but he presents evidence that such did happen, and even suggests how it could happen. Anomalies in deep rock crystals Physicist Dr. Robert Gentry has pointed out that the amount of helium and lead in zircons from deep bores is not consistent with an evolutionary age of 1, Ma for the granite rocks in which they are found.
Furthermore, the amount of helium in zircons from hot rock is also much more consistent with a young Earth helium derives from the decay of radioactive elements. The lead and helium results suggest that rates of radioactive decay may have been much higher in the recent past. Humphreys has suggested that this may have occurred during creation week and the flood. This would make things look much older than they really are when current rates of decay are applied to dating.
Whatever caused such elevated rates of decay may also have been responsible for the lead isotope conversions claimed by Cook above. Orphan radiohalos Decaying radioactive particles in solid rock cause spherical zones of damage to the surrounding crystal structure. A speck of radioactive element such as Uranium, for example, will leave a sphere of discoloration of characteristically different radius for each element it produces in its decay chain to lead Gentry has researched radiohalos for many years, and published his results in leading scientific journals.
For example, Po has a half-life of just 3 minutes. Curiously, rings formed by polonium decay are often found embedded in crystals without the parent uranium halos.
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Now the polonium has to get into the rock before the rock solidifies, but it cannot derive a from a uranium speck in the solid rock, otherwise there would be a uranium halo.
Either the polonium was created primordial, not derived from uraniumor there have been radical changes in decay rates in the past. Gentry has addressed all attempts to criticize his work.
Whatever process was responsible for the halos could be a key also to understanding radiometric dating. We don't have all the answers, but we do have the sure testimony of the Word of God to the true history of the world. Footnotes Also known as isotope or radioisotope dating. Today, a stable carbon isotope, 13Cis measured as an indication of the level of discrimination against 14C. Radiation from atomic testing, like cosmic rays, causes the conversion of 14N to 14C.
Tree ring dating dendrochronology has been used in an attempt to extend the calibration of the calibration of carbon dating earlier than historical records allow, but this depends on temporal placement of fragments of wood from long dead trees using carbon dating, assuming straight-line extrapolation backwards.
Government Printing Office, Washington D. Musk ox muscle was dated at 24, years, but hair was dated at 17, years.