Radiocarbon dating is possible because, while alive, plants, animals and humans absorb tiny amounts of radioactive carbon-14 from the atmosphere.
When they die, absorption stops and the amount of carbon-14 begins to decrease in a predictable way as described by the law of radioactive decay.
But carbon-14 levels have fluctuated over time, so to allow accurate dating, an adjustment must be made using a calibration curve.
To illustrate the exact spectrum of looks we’re talking about here, and to put some human faces on our discussion, I want to introduce a few photos of real Ok Cupid users.Funnily enough, I had to write about a dozen beautiful female users before anyone would even get back to me. Anyhow, I know attractiveness is far from a universal concept, but maybe keep these folks in mind as we go through the data.Our chart shows how men have rated women, on a scale from 0 to 5.To give an example if a sample is found to have a radiocarbon concentration exactly half of that for material which was modern in 1950 the radiocarbon measurement would be reported as 5568 BP.For two important reasons, this does not mean that the sample comes from 3619 BC: Many types of tree reliably lay down one tree ring every year.