What are some of the problems with radioactive isotope dating
What are some of the problems with radioactive isotope dating
the method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. for example, if a magma chamber does not have homogeneously mixed isotopes, lighter daughter products could accumulate in the upper portion of the chamber. these radionuclides—possibly produced by the explosion of a supernova—are extinct today, but their decay products can be detected in very old material, such as that which constitutes meteorites. first, each age is based on numerous measurements; laboratory errors, had there been any, would be readily apparent. when scientists first began to compare carbon dating data to data from tree rings, they found carbon dating provided "too-young" estimates of artifact age. other dating techniques, like k-ar (potassium-argon and its more recent variant 40ar/39ar), rb-sr (rubidium-strontium), sm-nd (samarium-neodynium), lu-hf (lutetium-hafnium), and u-pb (uranium-lead and its variant pb-pb), have all stood the test of time. … in other words, radiometric dating methods are actually fit into the geological column, which was set up by [index] fossil dating over 100 years ago. krot(2002) dating the earliest solids in our solar system, hawai'i institute of geophysics and planetology http://www. creationists who wants to dispute the conclusion that primitive meteorites, and therefore the solar system, are about 4.-argon and argon-argon dating of crustal rocks and the problem of excess argon. carbon-14 is a radioactive isotope of carbon, with a half-life of 5,730 years, (which is very short compared with the above isotopes) and decays into nitrogen. clearly, it is important to have a good understanding of these processes in order to evaluate the reliability of radiometric dating. stated previously, carbon dating cannot be used on artifacts over about 50,000 years old. radiometric dating and the geological time scale: circular reasoning or reliable tools? sun alters radioactive decay rates many scientists rely on the assumption that radioactive elements decay at constant, undisturbed rates and therefore can be used as reliable clocks to measure the ages of rocks and artifacts. possible confounding variables are the mechanisms that can alter daughter-to-parent ratios. research has even identified precisely where radioisotope dating went wrong. with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geologic time scale. the short half-life of carbon-14 means it cannot be used to date fossils that are allegedly extremely old, e. for since the creation of the world god's invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that men are without excuse. it is these studies, and the many more like them documented in the scientific literature, that the creationists need to address before they can discredit radiometric dating. some so-called creation scientists have attempted to show that radiometric dating does not work on theoretical grounds (for example, arndts and overn 1981; gill 1996) but such attempts invariably have fatal flaws (see dalrymple 1984; york and dalrymple 2000). in other radiometric dating methods, the heavy parent isotopes were produced by nucleosynthesis in supernovas, meaning that any parent isotope with a short half-life should be extinct by now. is rare for a study involving radiometric dating to contain a single determination of age., various radioisotope methods or even various attempts using the same method yield discordant ages more often than concordant ages.
Radioactive dating fatal flaw -
Λ is the decay constant of the parent isotope, equal to the inverse of the radioactive half-life of the parent isotope times the natural logarithm of 2. 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. that is, at some point in time, an atom of such a nuclide will undergo radioactive decay and spontaneously transform into a different nuclide.–lead radiometric dating involves using uranium-235 or uranium-238 to date a substance's absolute age. in order to accomplish their goal of discrediting radiometric dating, however, creationists are faced with the daunting task of showing that a preponderance of radiometric ages are wrong — that the methods are untrustworthy most of the time. radiometric dating is also used to date archaeological materials, including ancient artifacts. also, many fossils are contaminated with carbon from the environment during collection or preservation procedures. carbon-14 dating: what does it really tell us about the age of the earth? there are so many complicated phenomena to consider like this that it calls the whole radiometric dating scheme into question. is not the only dating study to be done on an historic lava flow. accuracy levels of within twenty million years in ages of two-and-a-half billion years are achievable. the use of radiometric dating was first published in 1907 by bertram boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of the earth itself, and can also be used to date a wide range of natural and man-made materials. example of short-lived extinct radionuclide dating is the 26al – 26mg chronometer, which can be used to estimate the relative ages of chondrules. for rocks dating back to the beginning of the solar system, this requires extremely long-lived parent isotopes, making measurement of such rocks' exact ages imprecise. in many cases, the daughter nuclide itself is radioactive, resulting in a decay chain, eventually ending with the formation of a stable (nonradioactive) daughter nuclide; each step in such a chain is characterized by a distinct half-life. we can see that many varieties of minerals are produced from the same magma by the different processes of crystallization, and these different minerals may have very different compositions. results of the manson impact/pierre shale dating study (izett and others 1998) are shown in figure 1. this converts the only stable isotope of iodine (127i) into 128xe via neutron capture followed by beta decay (of 128i). since both the ash beds and the tektites occur either at or very near the k-t boundary, as determined by diagnostic fossils, the tektites and the ash beds should be very nearly the same age, and they are (table 2). new discoveries of rate fluctuations continue to challenge the reliability of radioisotope decay rates in general—and thus, the reliability of vast ages seemingly derived from radioisotope dating. this rules out carbon dating for most aquatic organisms, because they often obtain at least some of their carbon from dissolved carbonate rock. the assumptions are similar to the assumptions used in carbon dating. if radiometric dating didn’t work then such beautifully consistent results would not be possible.'t radioisotope dating prove rocks are millions of years old? after an organism has been dead for 60,000 years, so little carbon-14 is left that accurate dating can not be established.
Radiometric Dating: Problems with the Assumptions | Answers in
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billion years, providing a built-in crosscheck that allows accurate determination of the age of the sample even if some of the lead has been lost. these temperatures are experimentally determined in the lab by artificially resetting sample minerals using a high-temperature furnace. some are from primitive asteroids whose material is little modified since they formed from the early solar nebula. dating of grand canyon rocks: another devastating failure for long-age geology. but even if it is true that older radiometric dates are found lower down in the geologic column (which is open to question), this can potentially be explained by processes occurring in magma chambers which cause the lava erupting earlier to appear older than the lava erupting later.: radiometric datingconservation and restorationhidden categories: cs1 maint: multiple names: authors listwikipedia articles needing page number citations from september 2010use dmy dates from september 2010. two extensive studies done more than 25 years ago involved analyzing the isotopic composition of argon in such flows to determine if the source of the argon was atmospheric, as must be assumed in k-ar dating (dalrymple 1969, 26 flows; krummenacher 1970, 19 flows). the dating is simply a question of finding the deviation from the natural abundance of 26mg (the product of 26al decay) in comparison with the ratio of the stable isotopes 27al/24mg. in most instances, these efforts are flawed because the authors have misunderstood or misrepresented the data they attempt to analyze (for example, woodmorappe 1979; morris hm 1985; morris jd 1994). this human nuclear activity will make precise dating of fossils from our lifetime very difficult due to contamination of the normal radioisotope composition of the earth with addition artificially produced radioactive atoms. 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 1940's. the first is that each meteorite was dated by more than one laboratory — allende by 2 laboratories, guarena by 2 laboratories, and st severin by four laboratories."excess argon": the "archilles' heel" of potassium-argon and argon-argon "dating" of volcanic rocks. since such isotopes are thought to decay at consistent rates over time, the assumption is that simple measurements can lead to reliable ages. 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. while there are many problems with such dating methods, such as parent or daughter substances entering or leaving the rock, e. a related method is ionium–thorium dating, which measures the ratio of ionium (thorium-230) to thorium-232 in ocean sediment. ma using lead–lead dating, results that are consistent with each other. as a result, this method is not used except in rare and highly specialized applications. this short paper i have briefly described 4 examples of radiometric dating studies where there is both internal and independent evidence that the results have yielded valid ages for significant geologic events.. is a meteorologist and creationist scientist who writes, and when it comes to dating any individual rock today, the resulting “date” is forced to conform to predetermined evolutionist “dates” based on these imaginary 19th century index-fossil “dates”. all they indicate is that the methods are not infallible. furthermore, the dating was done in 6 different laboratories and the materials were collected from 5 different locations in the western hemisphere.–lead dating is often performed on the mineral zircon (zrsio4), though it can be used on other materials, such as baddeleyite, as well as monazite (see: monazite geochronology). numerous thin beds of volcanic ash occur within these coals just centimeters above the k-t boundary, and some of these ash beds contain minerals that can be dated radiometrically.
Radioactive dating fatal flaw -
Radiometric Dating Does Work! | NCSE
these isotopes have longer half-lives and so are found in greater abundance in older fossils. concordia diagram as used in uranium–lead dating, with data from the pfunze belt, zimbabwe. would really be nice if geologists would just do a double blind study sometime to find out what the distributions of the ages are. a number of processes could cause the parent substance to be depleted at the top of the magma chamber, or the daughter product to be enriched, both of which would cause the lava erupting earlier to appear very old according to radiometric dating, and lava erupting later to appear younger. important factor in radiometric dating is the concept that we have all these various elements for radiometric dating and why can’t they be used to validate one another? many people, radiometric dating might be the one scientific technique that most blatantly seems to challenge the bible’s record of recent creation. we need to observe when the race begins, how the race is run (are there variations from the course, is the runner staying within the course, are they taking performance enhancing drugs, etc.. leeching, as well as daughter product being present at the beginning, these confounding variables are ignored. assert that generally speaking, older dates are found deeper down in the geologic column, which they take as evidence that radiometric dating is giving true ages, since it is apparent that rocks that are deeper must be older. see the articles below for more information on the pitfalls of these dating methods. in uranium–lead dating, the concordia diagram is used which also decreases the problem of nuclide loss. secondly, you must have an observable time span so we can be certain nothing has affected the amount of the radioactive element being measured, e. beware of the conclusions of secular scientists who reject the truth of god’s word and lean to their own understanding. of a radioactive decay chain from lead-212 (212pb) to lead-208 (208pb) . its exact location in the stratigraphic column at any locality has nothing to do with radiometric dating — it is located by careful study of the fossils and the rocks that contain them, and nothing more. any radiometric dates that show a supposedly “old” rock to be young are rejected for no other reason:“few people realize that the index fossil dating system, despite its poor assumptions and many problems, is actually the primary dating tool for geologic time. uranium is water-soluble, thorium and protactinium are not, and so they are selectively precipitated into ocean-floor sediments, from which their ratios are measured. isotopes are commonly portrayed as providing rock-solid evidence that the earth is billions of years old. henry morris as follows:“index fossils” are types of fossil (such as ammonites and coelacanths) that 19th century european evolutionists of the victorian era claimed lived and died out many millions of years ago. for dates up to a few million years micas, tektites (glass fragments from volcanic eruptions), and meteorites are best used. in the case of st severin, for example, we have 4 different natural clocks (actually 5, for the pb-pb method involves 2 different radioactive uranium isotopes), each running at a different rate and each using elements that respond to chemical and physical conditions in much different ways. relatively short-range dating technique is based on the decay of uranium-234 into thorium-230, a substance with a half-life of about 80,000 years. all the samples show loss of lead isotopes, but the intercept of the errorchron (straight line through the sample points) and the concordia (curve) shows the correct age of the rock. 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-life, usually given in units of years when discussing dating techniques. rubidium-strontium dating is not as precise as the uranium-lead method, with errors of 30 to 50 million years for a 3-billion-year-old sample.
Radiometric dating - Wikipedia
not only that, they have to show the flaws in those dating studies that provide independent corroborative evidence that radiometric methods work. mathematical expression that relates radioactive decay to geologic time is. observations give us confidence that radiometric dating is not trustworthy. some meteorites, because of their mineralogy, can be dated by more than one radiometric dating technique, which provides scientists with a powerful check of the validity of the results. those of us who have developed and used dating techniques to solve scientific problems are well aware that the systems are not perfect; we ourselves have provided numerous examples of instances in which the techniques fail., most of which are fragments of asteroids, are very interesting objects to study because they provide important evidence about the age, composition, and history of the early solar system. 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 directly involved in this field. if we reverse the process to find the age of an alleged rock, the geologist takes his rock to the paleontologist, and the paleontologist goes to the same exact chart and looks for the “index fossil(s)” that normally are found in those rock layers. scientists who use radiometric dating typically use every means at their disposal to check, recheck, and verify their results, and the more important the results the more they are apt to be checked and rechecked by others. after irradiation, samples are heated in a series of steps and the xenon isotopic signature of the gas evolved in each step is analysed. finally, correlation between different isotopic dating methods may be required to confirm the age of a sample. most estimates of the age of the earth are founded on this assumption. because the fission tracks are healed by temperatures over about 200 °c the technique has limitations as well as benefits. confounding factors such as contamination and fractionation issues are frankly acknowledged by the geologic community, but are not taken into consideration when the accuracy and validity of these dating methods are examined. only rarely does a creationist actually find an incorrect radiometric result (austin 1996; rugg and austin 1998) that has not already been revealed and discussed in the scientific literature. isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years (e. there are three important things to note about these results. precision is enhanced if measurements are taken on multiple samples from different locations of the rock body. methods of radiometric dating vary in the timescale over which they are accurate and the materials to which they can be applied. all dating methods that support this theory are embraced, while any evidence to the contrary, e. it is possible that the ratio of daughter to parent substances for radiometric dating could differ in the different minerals. 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. we know the exact day of this eruption because pliny the younger carefully recorded the event. 79 ce mt vesuvius flow, the dating of which is described above, also contained excess 40ar. carbon-14 dating has been used successfully on the dead sea scrolls, minoan ruins and tombs of the pharaohs among other things.
Radiometric Dating | The Institute for Creation Research when an organism dies, it ceases to take in new carbon-14, and the existing isotope decays with a characteristic half-life (5730 years). 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. the age that can be calculated by radiometric dating is thus the time at which the rock or mineral cooled to closure temperature. certain decay rates apparently aren’t as stable as some would hope. however, construction of an isochron does not require information on the original compositions, using merely the present ratios of the parent and daughter isotopes to a standard isotope. among the best-known techniques are radiocarbon dating, potassium–argon dating and uranium–lead dating. stimulating these mineral grains using either light (optically stimulated luminescence or infrared stimulated luminescence dating) or heat (thermoluminescence dating) causes a luminescence signal to be emitted as the stored unstable electron energy is released, the intensity of which varies depending on the amount of radiation absorbed during burial and specific properties of the mineral. closure temperatures are so high that they are not a concern. scientists have concluded that it is not; it is instead a consequence of the fact that radiometric dating actually works and works quite well. instead, they are a consequence of background radiation on certain minerals. tests, nuclear reactors and the use of nuclear weapons have also changed the composition of radioisotopes in the air over the last few decades. few verified examples of incorrect radiometric ages are simply insufficient to prove that radiometric dating is invalid. dating methods are not radiometric dating methods in that they do not rely on abundances of isotopes to calculate age. if the earth were only 6000–10 000 years old, then surely there should be some scientific evidence to confirm that hypothesis; yet the creationists have produced not a shred of it so far. these long time periods are computed by measuring the ratio of daughter to parent substance in a rock, and inferring an age based on this ratio. at a certain temperature, the crystal structure has formed sufficiently to prevent diffusion of isotopes. rate of creation of carbon-14 appears to be roughly constant, as cross-checks of carbon-14 dating with other dating methods show it gives consistent results. the proportion of carbon-14 left when the remains of the organism are examined provides an indication of the time elapsed since its death. of these other isotopes include:Potassium-40 found in your body at all times; half-life = 1. is age of the sample,D is number of atoms of the daughter isotope in the sample,D0 is number of atoms of the daughter isotope in the original composition,N is number of atoms of the parent isotope in the sample at time t (the present), given by n(t) = noe-λt, and. and yet the results are the same within analytical error. the supposed age of “index fossils” is based on how long these 19th century evolutionists believed one kind of animal would take (somehow) to “evolve” into a different kind of animal. dating can now be performed on samples as small as a nanogram using a mass spectrometer. levels of carbon-14 become difficult to measure and compare after about 50,000 years (between 8 and 9 half lives; where 1% of the original carbon-14 would remain undecayed). of a meteorite called shallowater are usually included in the irradiation to monitor the conversion efficiency from 127i to 128xe.
Carbon-14, Radiometric Dating - CSI in practice, geologists carefully select what rocks they will date, and have many explanations for discordant dates, so it's not clear how such a study could be done, but it might be a good project for creationists. the age of the carbon in the rock is different from that of the carbon in the air and makes carbon dating data for those organisms inaccurate under the assumptions normally used for carbon dating. austin (1996) has documented excess 40ar in the 1986 dacite flow from mount st helens, but the amounts are insufficient to produce significant errors in all but the youngest rocks. additionally, elements may exist in different isotopes, with each isotope of an element differing in the number of neutrons in the nucleus. amounts of otherwise rare 36cl (half-life ~300ky) were produced by irradiation of seawater during atmospheric detonations of nuclear weapons between 1952 and 1958. the only exceptions are nuclides that decay by the process of electron capture, such as beryllium-7, strontium-85, and zirconium-89, whose decay rate may be affected by local electron density. this is extremely powerful verification of the validity of both the theory and practice of radiometric dating. radiometric dating methods use this basic principle to extrapolate the age of artifacts being tested. the fallout from this enormous impact, including shocked quartz and high concentrations of the element iridium, has been found in sedimentary rocks at more than 100 locations worldwide at the precise stratigraphic location of the cretaceous-tertiary (k-t) boundary (alvarez and asaro 1990; alvarez 1998). dating methods based on extinct radionuclides can also be calibrated with the u-pb method to give absolute ages. of these methods are accurate only back to the last global catastrophe (i. the second thing is that some of the results have been repeated using the same technique, which is another check against analytical errors. "approximation of terrestrial lead isotope evolution by a two-stage model". as the mineral cools, the crystal structure begins to form and diffusion of isotopes is less easy. the third is that all three meteorites were dated by more than one method — two methods each for allende and guarena, and four methods for st severin. creationist approach of focusing on examples where radiometric dating yields incorrect results is a curious one for two reasons. addition to shocked quartz grains and high concentrations of iridium, the k-t impact produced tektites, which are small glass spherules that form from rock that is instantaneously melted by a large impact. thus, as an event marker of 1950s water in soil and ground water, 36cl is also useful for dating waters less than 50 years before the present. and fractionation issues are frankly acknowledged by the geologic community. others are from larger asteroids that got hot enough to melt and send lava flows to the surface. most radioactive nuclides, the half-life depends solely on nuclear properties and is essentially a constant. the mass spectrometer was invented in the 1940s and began to be used in radiometric dating in the 1950s. are 3 important things to know about the ages in table 1. the procedures used to isolate and analyze the parent and daughter nuclides must be precise and accurate. mathematical premise undergirding the use of these elements in radiometric dating contains the similar confounding factors that we find in carbon-14 dating method.
The fatal flaw with radioactive dating methods – BiblicalGeology blog dating is used to determine the age of biological artifacts up to 50,000 years old. no — it is the result of extremely careful analyses using a technique that works. all bases must be covered if we are going to accurately time the race. attempt to check the accuracy of carbon dating by comparing carbon dating data to data from other dating methods. with scores of other bible-believing geologists, icr scientists have made key observations that compel us to reject the millions-of-years apparent ages that these techniques yield:First, rocks of known age always show vastly inflated radioisotope “ages. dating has been carried out since 1905 when it was invented by ernest rutherford as a method by which one might determine the age of the earth. radioactive potassium-40 is common in micas, feldspars, and hornblendes, though the closure temperature is fairly low in these materials, about 350 °c (mica) to 500 °c (hornblende). the half-life of carbon-14 makes it unreliable for dating fossils over about 50,000 years old, there are other isotopes scientists use to date older artifacts. what dating method did scientists use, and did it really generate reliable results? tektites are easily recognizable and form in no other way, so the discovery of a sedimentary bed (the beloc formation) in haiti that contained tektites and that, from fossil evidence, coincided with the k-t boundary provided an obvious candidate for dating. dating cannot be used on most fossils, not only because they are almost always allegedly too old, but also because they rarely contain the original carbon of the organism that has been fossilized. if this occurs, initial volcanic eruptions would have a preponderance of daughter products relative to the parent isotopes. each parent nuclide spontaneously decays into a daughter nuclide (the decay product) via an α decay or a β− decay. there are a few categories of artifacts that can be dated using carbon-14; however, they cannot be more 50,000 years old. the problems inherent in radiometric dating often cause them to be so unreliable that they contradict one another rather than validating each other. various confounding factors that can adversely affect the accuracy of carbon-14 dating methods are evident in many of the other radioisotope dating methods. the final decay product, lead-208 (208pb), is stable and can no longer undergo spontaneous radioactive decay. dating of rocks and minerals using naturally occurring, long-lived radioactive isotopes is troublesome for young-earth creationists because the techniques have provided overwhelming evidence of the antiquity of the earth and life. in the following article, some of the most common misunderstandings regarding radiocarbon dating are addressed, and corrective, up-to-date scientific creationist thought is provided where appropriate. 40ar/39ar dating into the historical realm: calibration against pliny the younger. a scenario does not answer all of the questions or solve all of the problems that radiometric dating poses for those who believe the genesis account of creation and the flood. for this reason, icr research has long focused on the science behind these dating techniques. such failures may be due to laboratory errors (mistakes happen), unrecognized geologic factors (nature sometimes fools us), or misapplication of the techniques (no one is perfect). dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. radiometric dating requires a measurable fraction of parent nucleus to remain in the sample rock.
Clocks in the Rocks for example, if they believed it would take 200 million years for an ammonite (somehow) to turn gradually into say a dog, then all rocks containing fossil ammonites (the “index fossil”) would be given an “age” 200 million years older than rocks containing fossils of dogs:“… the geological column and approximate ages of all the fossil-bearing strata were all worked out long before anyone ever heard or thought about radioactive dating … there are so many sources of possible error or misinterpretation in radiometric dating that most such dates are discarded and never used at all, notably whenever they disagree with the previously agreed-on [index fossil] dates.. the global flood of 2,348 bc) as global catastrophes reset all the radiometric/atomic “clocks” by invalidating the evolutionist’s main dating assumption that there have never been any global catastrophes. to be able to distinguish the relative ages of rocks from such old material, and to get a better time resolution than that available from long-lived isotopes, short-lived isotopes that are no longer present in the rock can be used. this age is computed under the assumption that the parent substance (say, uranium) gradually decays to the daughter substance (say, lead), so the higher the ratio of lead to uranium, the older the rock must be. the k-t tektites were ejected into the atmosphere and deposited some distance away. decay rates not stablefor about a century, radioactive decay rates have been heralded as steady and stable processes that can be reliably used to help measure how old rocks are. a particular isotope of a particular element is called a nuclide. dating of different minerals and/or isotope systems (with differing closure temperatures) within the same rock can therefore enable the tracking of the thermal history of the rock in question with time, and thus the history of metamorphic events may become known in detail. there is also evidence that many anomalies are never reported. other creationists have focused on instances in which radiometric dating seems to yield incorrect results. this temperature is what is known as closure temperature and represents the temperature below which the mineral is a closed system to isotopes., many dating methods that don't involve radioisotopes—such as helium diffusion, erosion, magnetic field decay, and original tissue fossils—conflict with radioisotope ages by showing much younger apparent ages. basic equation of radiometric dating requires that neither the parent nuclide nor the daughter product can enter or leave the material after its formation. precision of a dating method depends in part on the half-life of the radioactive isotope involved. 36cl has seen use in other areas of the geological sciences, including dating ice and sediments. although the half-life of some of them are more consistent with the evolutionary worldview of millions to billions of years, the assumptions used in radiometric dating put the results of all radiometric dating methods in doubt. creationists seem to think that a few examples of incorrect radiometric ages invalidate all of the results of radiometric dating, but such a conclusion is illogical. second, the radiometric age measurements, 187 of them, were made on 3 different minerals and on glass by 3 distinctly different dating methods (k-ar and 40ar/39ar are technical variations that use the same parent-daughter decay scheme), each involving different elements with different half-lives. radiometric dating generally requires that the parent has a long enough half-life that it will be present in significant amounts at the time of measurement (except as described below under "dating with short-lived extinct radionuclides"), the half-life of the parent is accurately known, and enough of the daughter product is produced to be accurately measured and distinguished from the initial amount of the daughter present in the material. this makes carbon-14 an ideal dating method to date the age of bones or the remains of an organism. where are the data and age calculations that result in a consistent set of ages for all rocks on earth, as well as those from the moon and the meteorites, no greater than 10 000 years? how could all of this be so if the 40ar/39ar dating technique did not work? for example, after extensive testing over many years, it was concluded that uranium-helium dating is highly unreliable because the small helium atom diffuses easily out of minerals over geologic time. the fission tracks produced by this process are recorded in the plastic film. the heat of the impact melted some of the feldspar crystals in the granitic rocks of the impact zone, thereby resetting their internal radiometric clocks.