Carbon 14 C , or radiocarbon , is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues to date archaeological, geological and hydrogeological samples. Its existence had been suggested by Franz Kurie in The primary natural source of carbon on Earth is cosmic ray action on nitrogen in the atmosphere, and it is therefore a cosmogenic nuclide.
Carbon 14 dating 2
BioMath: Carbon Dating
The term anno Domini is Medieval Latin and means "in the year of the Lord"  but is often presented using "our Lord" instead of "the Lord",   taken from the full original phrase " anno Domini nostri Jesu Christi ", which translates to "in the year of our Lord Jesus Christ ". This calendar era is based on the traditionally reckoned year of the conception or birth of Jesus, with AD counting years from the start of this epoch and BC denoting years before the start of the era. This dating system was devised in by Dionysius Exiguus of Scythia Minor , but was not widely used until after It is often directly contrasted to the more ancient, Anno Mundi AM conferring "in the years of the world" which recounts the ages based on biblical tradition beginning with the Creation account. To this day, it is firmly observed through virtually all Jewish religious sources, some minor non-Jewish orthodox societies, and is a reference in many aged and restituted manuscripts. The Gregorian calendar is the most widely used calendar in the world today.
Historical artefacts like moa bones can be dated using a technique that measures the activity of the radioisotope carbon still present in the sample. By comparing this with a modern standard, an estimate of the calendar age of the artefact can be made. To use this interactive, move your mouse or finger over any of the labelled boxes and click to obtain more information.