Carbon dating dinosaur bones wiki
In 20,000 years the concentration of C14 decreases by a factor of 0.089 (to less than a tenth) because (1/2) or about 7 billion C14 atoms in a mole of C12.
Thus a sample that dates to 40,000 years by C14 dating still has about 7 billion C14 atoms per mole of carbon.
Thus, measuring the ratio of D to L in a sample enables one to estimate how long ago the specimen died.
This dating method is considered to be accurate for ages up to several hundred thousand years.
In a 2015 paper in , her group reported isolating fragments of eight other proteins from fossils of dinosaurs and extinct birds, including hemoglobin in blood, the cytoskeletal protein actin, and histones that help package DNA. All amino acids except glycine (the simplest one) are optically active, having a stereocenter at their α-C atom.
This means that the amino acid can have two different configurations, “D” or “L” which are mirror images of each other.
That means that in 5730 years, half of the C14 will decay to nitrogen 14.Mary Schweitzer, a professor at North Carolina State University (North Carolina), has found soft tissue and protein in dinosaur bones.Even more, proteins in this tissue retain their structure.By measuring the C14/C12 ratio, one can get an estimate of the age for the date of a once living object or a fossil, assuming that the production of C14 and its decay rate have been constant in the past.These estimates are roughly correct for historic time, that is, the past several thousand years.