Radiocarbon dating

Living things take in carbon-14 while they live; after death it decays at a known rate, so the amount left in bone, wood, cloth or parchment gives the time since death, to within a few decades once calibrated against tree rings. On this site it dates the Voynich Manuscript's vellum to the early fifteenth century, the Shroud of Turin's cloth to the Middle Ages (a result still argued over), and the bones, hearths and seeds of a dozen excavations. It dates the material, not the making: old parchment can be written on late.