Several dating methods exist, depending on different criteria and techniques, and some very well known examples of disciplines using such techniques are, for example, history, archaeology, geology, paleontology, astronomy and even forensic science, since in the latter it is sometimes necessary to investigate the moment in the past in which the death of a cadaver occurred.Relative dating methods are unable to determine the absolute age of an object or event, but can determine the impossibility of a particular event happening before or after another event of which the absolute date is well known.That means that the play was without fail written after (in Latin, post) 1587.
Dating is very important in archaeology for constructing models of the past, as it relies on the integrity of dateable objects and samples.
Many disciplines of archaeological science are concerned with dating evidence, but in practice several different dating techniques must be applied in some circumstances, thus dating evidence for much of an archaeological sequence recorded during excavation requires matching information from known absolute or some associated steps, with a careful study of stratigraphic relationships.
For example, in a stratum presenting difficulties or ambiguities to absolute dating, paleopalynology can be used as a relative referent by means of the study of the pollens found in the stratum.
This is admitted because of the simple reason that some botanical species, whether extinct or not, are well known as belonging to a determined position in the scale of time.
The absolute dating method first appeared in 1907 with Lord Rutherford and Professor Boltwood at Yale University, but wasn’t accepted until the 1950s.
The first method was based on radioactive elements whose property of decay occurs at a constant rate, known as the half-life of the isotope.The stratigraphy of an archaeological site can be used to date, or refine the date, of particular activities ("contexts") on that site.For example, if a context is sealed between two other contexts of known date, it can be inferred that the middle context must date to between those dates.Chronological dating, or simply dating, is the process of attributing to an object or event a date in the past, allowing such object or event to be located in a previously established chronology.This usually requires what is commonly known as a "dating method".Another absolute dating method is thermoluminescence, which dates the last time an item was heated.