Radiocarbon- and calendar-years
One can date organic material less than c. 50 000 years by radiocarbon-dating since carbon, an essential building stone in living material, contains radioactive carbon. The method is of great help to date material, both in geology and archeology. Radiocarbon-years correspond not entirely the calendar years. It is difficult to specify the exact calendar year based on age dating since the proportion of radioactive carbon is not constant in the atmosphere over time. Scientists therefore prefer to use radiocarbon-years. In popular science given ages based on radiocarbon-material is confusing, since it isn’t normally specified. In this presentation ages are in calendar-years.