Carbon dating fact fiction
The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire in a sample from a dead plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died.The older a sample is, the less (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by this process date to around 50,000 years ago, although special preparation methods occasionally permit accurate analysis of older samples.Many scientists will use carbon dating test results to back up their position if the results agree with their preconceived theories.But if the carbon dating results actually conflict with their ideas, they aren't too concerned. Thorpe, Nikos Kokkinos, Robert Morkot and John Frankish), Preface to Centuries of Darkness, 1991) So, is carbon dating accurate?In addition to permitting more accurate dating within archaeological sites than previous methods, it allows comparison of dates of events across great distances.Histories of archaeology often refer to its impact as the "radiocarbon revolution".Carbon dating is somewhat accurate because we are able to determine what the ratio was in the unobservable past to a certain extent.By taking a carboniferous specimen of known age (that is, a specimen which we are able to date with reasonable certainty through some archaeological means), scientists are able to determine what the ratio was during a specimen's lifetime.
Unfortunately the ratio of carbon-12 to carbon-14 has yet to reach a state of equilibrium in our atmosphere; there is more carbon-14 in the air today than there was thousands of years ago.
The resulting data, in the form of a calibration curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the sample's calendar age.
Other corrections must be made to account for the proportion of throughout the biosphere (reservoir effects).
The results were summarized in a paper in Science in 1947, in which the authors commented that their results implied it would be possible to date materials containing carbon of organic origin.
Libby and James Arnold proceeded to test the radiocarbon dating theory by analyzing samples with known ages.