What is radioactive dating of rocks archeological dating
Symbolically, the process of radioactive decay can be expressed by the following differential equation, where N is the quantity of decaying nuclei and k is a positive number called the exponential decay constant.The meaning of this equation is that the rate of change of the number of nuclei over time is proportional only to the number of nuclei.Some isotopes have half lives longer than the present age of the universe, but they are still subject to the same laws of quantum physics and will eventually decay, even if doing so at a time when all remaining atoms in the universe are separated by astronomical distances.Various elements are used for dating different time periods; ones with relatively short half-lives like carbon-14 (or C) are useful for dating once-living objects (since they include atmospheric carbon from when they were alive) from about ten to fifty thousand years old. Longer-lived isotopes provide dating information for much older times.Most rocks contain uranium, allowing uranium-lead and similar methods to date them.Other elements used for dating, such as rubidium, occur in some minerals but not others, restricting usefulness.
Carbon-14 decays almost completely within 100,000 years of the organism dying, and many fossils and rock strata are hundreds of times older than that.
Radiometric dating — through processes similar to those outlined in the example problem above — frequently reveals that rocks, fossils, etc.
are very much older than the approximately 6,000 to 10,000 years reckoned by young earth creationists.
This leaves out important information which would tell you how precise is the dating result.
Carbon-14 dating has an interesting limitation in that the ratio of regular carbon to carbon-14 in the air is not constant and therefore any date must be calibrated using dendrochronology.