Age of the Earth - Wikipedia
May 9, If you are going to use carbon dating for the age off the Earth then the result will be wrong Carbon 14 has a half-life that is too short. Anything. The use of carbon, also known as radiocarbon, to date organic materials has been an important method in both archaeology and geology. The technique. Adapted from The Age of the Earth, by the Branch of Isotope Geology, United have been dated by four independent radiometric dating methods at
Ernest Rutherford in Ernest Rutherford and Frederick Soddy jointly had continued their work on radioactive materials and concluded that radioactivity was due to a spontaneous transmutation of atomic elements. In radioactive decay, an element breaks down into another, lighter element, releasing alpha, beta, or gamma radiation in the process.
They also determined that a particular isotope of a radioactive element decays into another element at a distinctive rate. This rate is given in terms of a " half-life ", or the amount of time it takes half of a mass of that radioactive material to break down into its "decay product".
Some radioactive materials have short half-lives; some have long half-lives. Uranium and thorium have long half-lives, and so persist in Earth's crust, but radioactive elements with short half-lives have generally disappeared. This suggested that it might be possible to measure the age of Earth by determining the relative proportions of radioactive materials in geological samples.
In reality, radioactive elements do not always decay into nonradioactive "stable" elements directly, instead, decaying into other radioactive elements that have their own half-lives and so on, until they reach a stable element.
These " decay chains ", such as the uranium-radium and thorium series, were known within a few years of the discovery of radioactivity and provided a basis for constructing techniques of radiometric dating. The pioneers of radioactivity were chemist Bertram B. Boltwood and the energetic Rutherford. Boltwood had conducted studies of radioactive materials as a consultant, and when Rutherford lectured at Yale in Boltwood was inspired to describe the relationships between elements in various decay series.
Late inRutherford took the first step toward radiometric dating by suggesting that the alpha particles released by radioactive decay could be trapped in a rocky material as helium atoms.
At the time, Rutherford was only guessing at the relationship between alpha particles and helium atoms, but he would prove the connection four years later. Soddy and Sir William Ramsay had just determined the rate at which radium produces alpha particles, and Rutherford proposed that he could determine the age of a rock sample by measuring its concentration of helium.
He dated a rock in his possession to an age of 40 million years by this technique. Rutherford wrote, I came into the room, which was half dark, and presently spotted Lord Kelvin in the audience and realized that I was in trouble at the last part of my speech dealing with the age of the Earth, where my views conflicted with his.
To my relief, Kelvin fell fast asleep, but as I came to the important point, I saw the old bird sit up, open an eye, and cock a baleful glance at me! Then a sudden inspiration came, and I said, "Lord Kelvin had limited the age of the Earth, provided no new source was discovered. That prophetic utterance refers to what we are now considering tonight, radium! Rutherford's scheme was inaccurate, but it was a useful first step. Boltwood focused on the end products of decay series.
Inhe suggested that lead was the final stable product of the decay of radium. It was already known that radium was an intermediate product of the decay of uranium. Rutherford joined in, outlining a decay process in which radium emitted five alpha particles through various intermediate products to end up with lead, and speculated that the radium-lead decay chain could be used to date rock samples. Boltwood did the legwork, and by the end of had provided dates for 26 separate rock samples, ranging from 92 to million years.
He did not publish these results, which was fortunate because they were flawed by measurement errors and poor estimates of the half-life of radium. Boltwood refined his work and finally published the results in His studies were flawed by the fact that the decay series of thorium was not understood, which led to incorrect results for samples that contained both uranium and thorium. However, his calculations were far more accurate than any that had been performed to that time.
Refinements in the technique would later give ages for Boltwood's 26 samples of million to 2. Rutherford remained mildly curious about the issue of the age of Earth but did little work on it. Robert Strutt tinkered with Rutherford's helium method until and then ceased.
However, Strutt's student Arthur Holmes became interested in radiometric dating and continued to work on it after everyone else had given up.
How Science Figured Out the Age of Earth - Scientific American
Holmes focused on lead dating, because he regarded the helium method as unpromising. He performed measurements on rock samples and concluded in that the oldest a sample from Ceylon was about 1. For example, he assumed that the samples had contained only uranium and no lead when they were formed.9.6 Radioactive dating (Nuclear chemistry) (Chemistry - Class 11 & Class 12)
More important research was published in It showed that elements generally exist in multiple variants with different masses, or " isotopes ". In the s, isotopes would be shown to have nuclei with differing numbers of the neutral particles known as " neutrons ".
In that same year, other research was published establishing the rules for radioactive decay, allowing more precise identification of decay series.
Age of the Earth
Many geologists felt these new discoveries made radiometric dating so complicated as to be worthless. His work was generally ignored until the s, though in Joseph Barrella professor of geology at Yale, redrew geological history as it was understood at the time to conform to Holmes's findings in radiometric dating.
Barrell's research determined that the layers of strata had not all been laid down at the same rate, and so current rates of geological change could not be used to provide accurate timelines of the history of Earth.
Holmes published The Age of the Earth, an Introduction to Geological Ideas in in which he presented a range of 1. No great push to embrace radiometric dating followed, however, and the die-hards in the geological community stubbornly resisted. They had never cared for attempts by physicists to intrude in their domain, and had successfully ignored them so far. Holmes, being one of the few people on Earth who was trained in radiometric dating techniques, was a committee member, and in fact wrote most of the final report.
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 14C left.
How Science Figured Out the Age of Earth
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 14C in the atmosphere is not always constant. However, cross-checking techniques such as tree ring dating and coral analysis, 14C 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 14C 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. 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 14C 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 14C but actually contain very small amounts of it.
Since the accelerated mass spectrometer can detect 14C to a higher precision than what was found in the samples, the 14C 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 14C found in very old samples, the Rate team first discusses the possibility of contamination.
Besides the cosmic rays creating 14C in the atmosphere, other ways to create 14C have been identified. Alpha particle emissions from uranium and thorium decay can convert 14N into 14C just as it is formed in the atmosphere. However, as Baumgardner discusses the possible contamination through these processes, he concludes that "production of 14C by thermal neutrons at presently observed levels in unable, by several orders of magnitude, to account for the 14C levels we measure" Baumgardner The RATE team has used this anomaly to advance an alternative theory.
Noting that 14C exists in samples which should be 14C 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 14C. 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 14C 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. However, the entire idea is based on an arbitrary, unproven assumption. Without the Bible, there is no reason to believe that all of the life represented in the fossil record was alive at the same time, creating a different ratio of 14C to carbon than we see now.
There is also no reason, other than the Bible, to assume that there was a world-wide flood.