Absolute or radiometric dating
These are often characterised as the norm, rather than the exception.
This, of course, is so that it can be properly catalogued, and, if valid, can be related to or associated with other objects from the same era. Fossils and artifacts don't come with labels attached that clearly state their age.For example, in decomposing organic bodies - such as an animal carcass - carbon-14, an isotope of carbon, is present.Overtime, the C-14 atoms give off radiation, and, eventually, transform into nitrogen-14 atoms.The example used here contrasts sharply with the way conventional scientific dating methods are characterized by some critics (for example, refer to discussion in "Common Creationist Criticisms of Mainstream Dating Methods" in the Age of the Earth FAQ and Isochron Dating FAQ).A common form of criticism is to cite geologically complicated situations where the application of radiometric dating is very challenging.For example, techniques based on isotopes with half lives in the thousands of years, such as Carbon-14, cannot be used to date materials that have ages on the order of billions of years, as the detectable amounts of the radioactive atoms and their decayed daughter isotopes will be too small to measure within the uncertainty of the instruments.
One of the most widely used and well-known absolute dating techniques is carbon-14 (or radiocarbon) dating, which is used to date organic remains.
Absolute dating provides a numerical age or range in contrast with relative dating which places events in order without any measure of the age between events.
In archaeology, absolute dating is usually based on the physical, chemical, and life properties of the materials of artifacts, buildings, or other items that have been modified by humans and by historical associations with materials with known dates (coins and written history).
and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of the Earth itself, and can also be used to date a wide range of natural and man-made materials.
Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geological time scale.
his document discusses the way radiometric dating and stratigraphic principles are used to establish the conventional geological time scale.