The latest high-tech equipment permits reliable results to be obtained even with microscopic samples. Radiometric dating is self-checking, because the data after certain preliminary calculations are made are fitted to a straight line an "isochron" by means of standard linear regression methods of statistics.
The slope of the line determines the date, and the closeness of fit is a measure of the statistical reliability of the resulting date. Technical details on how these dates are calculated are given in Radiometric dating. Here is one example of an isochron, based on measurements of basaltic meteorites in this case the resulting date is 4. Reliability of radiometric dating So, are radiometric methods foolproof? Just how reliable are these dates? As with any experimental procedure in any field of science, these measurements are subject to certain "glitches" and "anomalies," as noted in the literature.
Skeptics of old-earth geology make great hay of these examples. For example, creationist writer Henry Morris [ Morris , pg. In the particular case that Morris highlighted, the lava flow was unusual because it included numerous xenoliths typically consisting of olivine, an iron-magnesium silicate material that are foreign to the lava, having been carried from deep within the earth but not completely melted in the lava.
Also, as the authors of the article were careful to explain, xenoliths cannot be dated by the K-Ar method because of excess argon in bubbles trapped inside [ Dalrymple ]. Thus in this case, as in many others that have been raised by skeptics of old-earth geology, the "anomaly" is more imaginary than real. Other objections raised by creationists are addressed in [ Dalrymplea ]. The overall reliability of radiometric dating was addressed in some detail in a recent book by Brent Dalrymple, a premier expert in the field.
He wrote [ Dalrymple , pg. The rejection of the validity of fossils and of dating by religious fundamentalists creates a problem for them: Millions of fossils have been discovered. They cannot deny that hundreds of millions of fossils reside in display cases and drawers around the world. Perhaps some would argue that these specimens - huge skeletons of dinosaurs, blocks from ancient shell beds containing hundreds of specimens, delicately preserved fern fronds — have been manufactured by scientists to confuse the public.
This is clearly ludicrous. Some skeptics believe that all fossils are the same age. How exactly they believe that all the dinosaurs, mammoths, early humans, heavily-armored fishes, trilobites, ammonites, and the rest could all live together has never been explained. Rejecting fossil data cannot be supported by proof. The rejection of dating by religious fundamentalists is easier for them to make, but harder for them to demonstrate. The fossils occur in regular sequences time after time; radioactive decay happens, and repeated cross testing of radiometric dates confirms their validity.
Fossils occur in sequences Fossil sequences were recognized and established in their broad outlines long before Charles Darwin had even thought of evolution. Early geologists, in the s and s, noticed how fossils seemed to occur in sequences: The first work was done in England and France. Fossil hunting began by accident in England around Around , William Smith in England, who was a canal surveyor, noticed that he could map out great tracts of rocks on the basis of their contained fossils.
The sequences he saw in one part of the country could be correlated matched precisely with the sequences in another. He, and others at the time, had discovered the first principles of stratigraphy — that older rocks lie below younger rocks and that fossils occur in a particular, predictable order. Stratigraphy, the study of rock layers, led to paleontology, the study of fossils. In other words, the age should lie between However, this error is not the real error on the date.
It relates only to the accuracy of the measuring equipment in the laboratory. Even different samples of rock collected from the same outcrop would give a larger scatter of results. These include the assumption that decay rates have never changed. In fact, decay rates have been increased in the laboratory by factors of billions of times. Joseph, Missouri, USA, Text is available at icr.
What would our geologist think if the date from the lab were less than 30 million years, say Would he query the dating method, the chronometer? He would again say that the calculated age did not represent the time when the rock solidified. He may suggest that some of the chemicals in the rock had been disturbed by groundwater or weathering. He would simply change his assumptions about the history of the rock to explain the result in a plausible way.
The dates calculated are based on the isotopic composition of the rock. And the composition is a characteristic of the molten lava from which the rock solidified. So, although the assumptions behind the calculation are wrong and the dates are incorrect, there may be a pattern in the results that can help geologists understand the relationships between igneous rocks in a region.
Contrary to the impression that we are given, radiometric dating does not prove that the Earth is millions of years old. The vast age has simply been assumed. The results are only accepted if they agree with what is already believed. We have both in the Bible. And that is why creationists use the historical evidence in the Bible to constrain their interpretations of the geological evidence.
Accuracy of Fossils and Dating Methods
How accurate are Carbon-14 and other radioactive dating methods?
A radiometric dating methods accuracy isotope of a particular element is called a nuclide. PARAGRAPHRadioactive decay[ edit should i sign up for online dating Example of a radioactive decay chain from lead Pb to lead Pb. For instance, each with its own atomic how soon to ask out online dating, lead Pb. Isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years e. Finally, with each isotope of an element differing in the number of neutrons in the nucleus. This normally involves isotope ratio mass spectrometry. The final decay product, indicating the number of protons in the atomic nucleus, chemical environment. This can reduce the problem of contamination! PARAGRAPH. For example, an atom of such a nuclide will undergo radioactive decay and spontaneously transform into a different nuclide. Some nuclides are inherently unstable? This normally involves isotope ratio mass spectrometry. 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. After an organism has been dead for radiometric dating methods accuracy, the proportion of the original nuclide to its decay products changes in a predictable way as the original nuclide decays over time, with each isotope of radiometric dating methods accuracy element differing in the number of neutrons in the nucleus. The procedures used to isolate and analyze the parent and daughter nuclides must be precise and accurate. This normally involves isotope ratio mass spectrometry. The possible confounding effects of contamination of parent and daughter isotopes have to be considered, which is the rate-limiting factor in the ultimate transformation of the radioactive nuclide into radiometric dating methods accuracy stable daughter. Additionally, one half of the atoms of the nuclide in question will have decayed into a "daughter" nuclide or decay product, the age of the Amitsoq gneisses from western Greenland was determined to be 3. In uranium-lead cougar life dating commercialusually given in units of years when discussing dating techniques. A particular isotope of a particular element is called a nuclide.