Using the earth for radiometric dating Sextalk room mit cam
His estimate came into question after the discovery of naturally occurring radioactivity by the French physicist Henri Becquerel in 1896 and the subsequent recognition by his colleagues, Marie and Pierre Curie, that compounds of radium (which occur in uranium minerals)...Another role of isotopic geochemistry that is of great importance in geology is radiometric age dating. Beginning with studies in the 1950s, a much better chronology and record of Pleistocene climatic events have evolved through analyses of deep-sea sediments, particularly from the oxygen isotope record of the shells of microorganisms that lived in the oceans.In 1905, shortly after the discovery of radioactivity, the American chemist Bertram Boltwood suggested that lead is one of the disintegration products of uranium, in which case the older a uranium-bearing mineral the greater should be its proportional part of lead.Analyzing specimens whose relative geologic ages were known, Boltwood found that the ratio of lead to uranium did indeed increase...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 is radioactive, resulting in a decay chain.Radioactive elements "decay" (that is, change into other elements) by "half lives." If a half life is equal to one year, then one half of the radioactive element will have decayed in the first year after the mineral was formed; one half of the remainder will decay in the next year (leaving one-fourth remaining), and so forth.The formula for the fraction remaining is one-half raised to the power given by the number of years divided by the half-life (in other words raised to a power equal to the number of half-lives).
However, when we speak of the distant past, there are no historical records and thus no verifiable way to prove that a certain 'date' is correct.What is less commonly known are any of the details of how the issue was settled: such as that the 4.5 billion year 'date' came from a single meteorite that was assumed to be the same age as the earth's core.And since this favored 'date' is the only one that's trumpeted by the media it is the only date that many assume to be correct.There are at least 67 different uniformitarian (the present is the key to the past) methods of dating the earth other than long-age radiometric dating: each of which yield ages of less than 500 million years.
Yet all these other science-based methods that point to a much younger age than 4.5 billion years for earth's age are ignored or rejected by evolution-believing people with degrees from college who apparently think that nobody (of importance) made them. Yet when asked why they reject all but the oldest science-based dating methods, the answer often given is that (they think) long-age radiometric dating is more reliable and that science settled the matter of the earth's age many years ago.
By establishing geological timescales, radiometric dating provides a significant source of information about the ages of fossils and rates of evolutionary change, and it is also used to date archaeological materials, including ancient artifacts.