This inconsistent amount of carbon-14 renders the test less accurate but opens up testing possibilities not available for older samples.
Carbon-14 is a radioactive isotope used to date organic material.
Its consistent rate of decay allows the age of an object to be determined by the proportion of carbon-14 to other carbon isotopes. Carbon-14 is also used as a radioactive tracer for medical tests.
Human remains, fossils and organic materials from archaeological sites are all dated using carbon-14.
Books, clothing and food remains are all archaeological artifacts that can be carbon dated.
Carbon-based rocks, such as bitumen and tephra, can also be dated in this manner.
Carbon dating is most effective on material that predates the 1940s; this is due to above-ground nuclear tests increasing the amount of carbon-14 in the environment.