In the case of 14 C, every 5, years half of the original 14 C decays into nitrogen. Eventually, there is too little 14 C left in a sample to accurately measure without contamination. Theoretically, radiocarbon techniques have the ability to date samples to around 75, years, but the working threshold of reliable dating is around 50, years. Samples significantly older than this have very little or even no measurable 14 C left. In order to function properly, natural clocks need an irreversible process that occurs at a constant and known rate.
Nuclear decay has a constant rate of decay, but as it turns out, the formation of 14 C in the atmosphere is not always constant. However, cross-checking techniques such as tree ring dating and coral analysis, 14 C has been reliably calibrated to tens of thousands of years.
The newest limit using cross-checking methods is around 26, years Dotinga Carbon isotopes are generally measured through the use of a machine called the accelerated mass spectrometer. A small portion of the sample is put into the machine which then vaporizes it. Taking advantage of the distinct mass of individual isotopes, the machine distinguishes the 14 C from all of the other atoms and molecules present and is able to count the individual atoms.
Charcoal, cloth, bone, or any other material that contains organic carbon can be dated using an accelerated mass spectrometer. In conjunction with other creationist organizations, the Institute for Creation Research has assembled a team of researchers to challenge existing notions about the age of the Earth. The RATE team Radioisotopes and the Age of the Earth have studied a variety of subjects pertaining to the age of the Earth including radiocarbon dating. In the traditional model of science, radiocarbon has little to do with the age of the Earth, since its lifespan is so short.
Professor Timothy H. Heaton
However, RATE is attempting to fit all radiometric dating into a young earth model. The RATE research in the area of radiocarbon has focused on the "blank" sample date. According to the science behind radiocarbon dating, very old samples should have no measurable 14 C left. However, conventional scientific research projects, as well as RATE research on coal beds and diamonds, have found samples which should no longer have any 14 C but actually contain very small amounts of it.
Since the accelerated mass spectrometer can detect 14 C to a higher precision than what was found in the samples, the 14 C is thought to exist because of some sort of unexplained phenomenon or contamination. Therefore, the RATE team has identified a valid anomaly in radiocarbon research which deserves further research.
Before proposing their alternate theory about the residual 14 C found in very old samples, the Rate team first discusses the possibility of contamination. Besides the cosmic rays creating 14 C in the atmosphere, other ways to create 14 C have been identified. Alpha particle emissions from uranium and thorium decay can convert 14 N into 14 C just as it is formed in the atmosphere. However, as Baumgardner discusses the possible contamination through these processes, he concludes that "production of 14 C by thermal neutrons at presently observed levels in unable, by several orders of magnitude, to account for the 14 C levels we measure" Baumgardner The RATE team has used this anomaly to advance an alternative theory.
Noting that 14 C exists in samples which should be 14 C dead and thus providing an age for the samples around 50, years, the RATE team has come up with a theory for how such an inconsistency could occur. After rejecting contamination as a possibility for the presence of background radiocarbon, the team has come up with a model in which the accounts outlined in the Bible, specifically Noah's flood, explains the observed 14 C.
All of the individuals who participated in the research began with the same view on the age of the earth: This means that we regard the bible as a uniquely inspired book given to mankind from the Creator" DeYoung In creating their 14 C model, that premise is used as the foundation. The logic for the theory is as follows: This means that radiocarbon dating actually proves the fossils are 5, years old, not 50, The RATE team has applied an inverse system of logic to the standard.
They begin with the same assumption that they are trying to prove. Broken down, the logic holds that the Bible says that the earth is very young; therefore the earth is very young. Without such a beginning claim, the logic would be extremely bizarre. Basically, the claim made by the RATE team is that the maximum date of 50, years given by radiocarbon dating actually equals 6, years. To start, let's look at the one which almost everyone has heard of: The element carbon occurs naturally in three nuclides: C12, C13, and C The vast majority of carbon atoms, about About one atom in billion is C The remainder are C Of the three, C12 and C13 are stable.
C14 is radioactive, with a half-life of years. C14 is also formed continuously from N14 nitrogen in the upper reaches of the atmosphere. And since carbon is an essential element in living organisms, C14 appears in all terrestrial landbound living organisms in the same proportions it appears in the atmosphere. Plants and protists get C14 from the environment.
Animals and fungi get C14 from the plant or animal tissue they eat for food. When an organism dies, it stops taking in C If we measure how much C14 there currently is, we can tell how much there was when the organism died, and therefore how much has decayed.
The Age of the Earth - Radiocarbom Dating as a Current Scientific Clock: Jonathan Ring
When we know how much has decayed, we know how old the sample is. Many archaeological sites have been dated by applying radiocarbon dating to samples of bone, wood, or cloth found there. Radiocarbon dating depends on several assumptions. One is that the thing being dated is organic in origin. Radiocarbon dating does not work on anything inorganic, like rocks or fossils. Only things that once were alive and now are dead: The second assumption is that the organism in question got its carbon from the atmosphere. A third is that the thing has remained closed to C14 since the organism from which it was created died.
The fourth one is that we know what the concentration of atmospheric C14 was when the organism lived and died. That last one is more important than it sounds. When Professor William Libby developed the C14 dating system in , he assumed that the amount of C14 in the atmosphere was a constant.
A long series of studies of C14 content produced an equally long series of corrective factors that must be taken into account when using C14 dating. So the dates derived from C14 decay had to be revised. One reference on radiometric dating lists an entire array of corrective factors for the change in atmospheric C14 over time.
C14 dating serves as both an illustration of how useful radiometric dating can be, and of the pitfalls that can be found in untested assumptions. U and U are both nuclides of the element uranium. U is well known as the major fissionable nuclide of uranium. It has a half-life of roughly million years. U is more stable, with a half-life of 4. Th is the most common nuclide of the element thorium, and has a half-life of All three of these nuclides are the starting points for what are called radioactive series.
A radioactive series is a sequence of nuclides that form one from another by radioactive decay. The series for U looks like this: A indicates alpha decay; B indicates beta decay. We can calculate the half-lives of all of these elements. All the intermediate nuclides between U and Pb are highly unstable, with short half-lives. Then any excess of Pb must be the result of the decay of U When we know how much excess Pb there is, and we know the current quantity of U, we can calculate how long the U in our sample has been decaying, and therefore how long ago the rock formed.
Th and U also give rise to radioactive series -- different series from that of U, containing different nuclides and ending in different nuclides of lead. Chemists can apply similar techniques to all three, resulting in three different dates for the same rock sample. Uranium and thorium have similar chemical behavior, so all three of these nuclides frequently occur in the same ores. If all three dates agree within the margin of error, the date can be accepted as confirmed beyond a reasonable doubt.
Since all three of these nuclides have substantially different half-lives, for all three to agree indicates the technique being used is sound. But even so, radioactive-series dating could be open to question. The rock being dated must remain a closed system with respect to uranium, thorium, and their daughter nuclides for the method to work properly.
Both the uranium and thorium series include nuclides of radon, an inert gas that can migrate through rock fairly easily even in the few days it lasts. To have a radiometric dating method that is unquestionably accurate, we need a radioactive nuclide for which we can get absolutely reliable measurements of the original quantity and the current quantity.
Radiometric Dating and Creation Science
Is there any such nuclide to be found in nature? The answer is yes. Which brings us to the third method of radiometric dating. The element potassium has three nuclides, K39, K40, and K Only K40 is radioactive; the other two are stable. K40 is unusual among radioactive nuclides in that it can break down two different ways.
It can emit a beta particle to become Ca40 calcium , or it can absorb an electron to become Ar40 argon Argon is a very special element. Argon is a gas at Earth-normal temperatures, and in any state it exists only as single atoms. By contrast, potassium and calcium are two of the most active elements in nature. They both form compounds readily and hold onto other atoms tenaciously. What does this mean? It means that before a mineral crystallizes, argon can escape from it easily.
It also means that when an atom of argon forms from an atom of potassium inside the mineral, the argon is trapped in the mineral. So any Ar40 we find deep inside a rock sample must be there as a result of K40 decay. That and some simple calculations produce a figure for how long the K40 has been decaying in our rock sample. What happens if our mineral sample has not remained a closed system?
What if argon has escaped from the mineral? What if argon has found its way into the mineral from some other source? If some of the radiogenic argon has escaped, then more K40 must have decayed than we think -- enough to produce what we did find plus what escaped. In other words, a mineral that has lost argon will be older than the result we get says it is. In the other direction, if excess argon has gotten into the mineral, it will be younger than the result we get says it is.
An isochron dating method isochron dating is described in the next section can also be applied to potassium-argon dating under certain very specific circumstances. When isochron dating can be used, the result is a much more accurate date. Yet a fourth method, rubidium-strontium dating, is even better than potassium-argon dating for old rocks. The nuclide rubidium Rb87 decays to strontium Sr87 with a half-life of 47 billion years.
Strontium occurs naturally as a mixture of several nuclides. If three minerals form at the same time in different regions of a magma chamber, they will have identical ratios of the different strontium nuclides. The total amount of strontium might be different in the different minerals, but the ratios will be the same. Now, suppose that one mineral has a lot of Rb87, another has very little, and the third has an in-between amount. That means that when the minerals crystallize there is a fixed ratio of Rb As time goes on, atoms of Rb87 decay to Sr, resulting in a change in the Rb Sr87 ratio, and also in a change in the ratio of Sr87 to other nuclides of strontium.
The decrease in the Rb Sr87 ratio is exactly matched by the gain of Sr87 in the strontium-nuclide ratio. It has to be -- the two sides of the equation must balance. If we plot the change in the two ratios for these three minerals, the resulting graph comes out as a straight line with an ascending slope. This line is called an isochron. When every one of four or five different minerals from the same igneous formation matches the isochron perfectly, it can safely be said that the isochron is correct beyond a reasonable doubt.
There are numerous other radiometric dating methods: A full cite for this book is given in the bibliography. Now, why is all this relevant to the creation-vs. Every method of radiometric dating ever used points to an ancient age for the Earth. For creationists to destroy the old-Earth theory, they must destroy the credibility of radiometric dating. They have two ways to do this. They can criticize the science that radiometric dating is based on, or they can claim sloppy technique and experimental error in the laboratory analyses of radioactivity levels and nuclide ratios.
Is there any way to criticize the theory of radiometric dating? Well, look back at the axioms of radiometric dating methods. Are any of those open to question. Or at least, they seem to be. Do we know, for a fact, that half-lives are constant axiom 1? Do we know for a fact that nuclide ratios are constant axiom 2? Regarding the first question: However, if all we had were theoretical reasons for believing axiom 1, we would be right to be suspicious of it.
Do we have observational evidence? On several occasions, astronomers have been able to analyze the radiation produced by supernovas.
- zodiac signs dating chart.
- rail science matchmaking.
- tell us about yourself examples dating;
- black man dating in china!
In a supernova, the vast amount of energy released creates every known nuclide via atomic fusion and fission. Some of these nuclides are radioactive. We can also detect the characteristic radiation signatures of radioactive decay in those nuclides. We can use that information to calculate the half-lives of those nuclides. In every case where this has been done, the measured radiation intensity and the calculated half-life of the nuclide from the supernova matches extremely well with measurements of that nuclide made here on Earth. And when we look at a supernova in the Andromeda Galaxy, 2,, years old, we see nuclides with the exact same half-lives as we see here on Earth.
Not just one or two nuclides, but many. For these measurements to all be consistently wrong in exactly the same way, most scientists feel, is beyond the realm of possibility. What about nuclide ratios? Are they indeed constant? Minerals form by recognized chemical processes that depend on the chemical activity of the elements involved. The chemical behavior of an element depends on its size and the number of electrons in its outer shell.
This is the foundation of the periodic table of the elements, a basic part of chemistry that has stood without challenge for a hundred and fifty years. The shell structure depends only on the number of electrons the nuclide has, which is the same as the number of protons in its nucleus. K39 is chemically identical to K40; the only way we can distinguish between them is to use a nonchemical technique like mass spectrometry. Water molecules containing oxygen are lighter and therefore evaporate faster than water molecules with oxygen However, as far as is known such fractionation occurs only with light nuclides: Sr86 atoms and Sr87 atoms behave identically when they bond with other atoms to form a mineral molecule.
If there are ten Sr86 atoms for every Sr87 atom in the original magma melt, there will be ten Sr86 atoms for every Sr87 atom in the minerals that crystallize from that melt. The only other possible source of error is in laboratory technique. To translate theory into useful measurements, the lab procedures must be accurate.
- dating someone 8 years older than me.
- dating site that does not require credit card.
- best dating site in trinidad and tobago.
A contaminated rock sample is useless for dating. A sample that is taken from the surface, where atoms could get in and out easily, is also useless. Samples must be taken by coring, from deep within a rock mass. To date a rock, chemists must break it down into its component elements using any of several methods, then analyze nuclide ratios using a mass spectrometer. But we can try to minimize error.
And when we do, the dates produced can be accepted as accurate. When samples taken from different parts of a given igneous rock formation are dated by different people at different labs over many years, the possibility that all those measurements could be wrong is vanishingly small. Some may well be wrong. If nine analyses agree, and a tenth produces radically different results, the odd-man-out is usually considered a result of some kind of error and discarded. And some radiometric techniques have a much better success ratio than that.