Can carbon dating
From then on, the ratio of radiocarbon to stable carbon will decrease, because the unstable radiocarbon atoms will slowly decay. From this measurement the age in radiocarbon years is calculated. Modern radiocarbon dates are calibrated using long tree-ring chronologies.
After about 50,000 years, the radiocarbon concentration remaining is too small to be measured for the purpose of radiocarbon dating. This is necessary to remove errors in raw radiocarbon dates caused by fluctuations in the amount of radiocarbon in the atmosphere in the past.
It's almost as if Morgan packed every awesome, bombastic sci-fi idea he ever had into one novel, just in case he never had the chance to do this sort of thing again.This tendency to decay, called radioactivity, is what gives radiocarbon the name radiocarbon.The atmosphere contains many stable carbon atoms and relatively few radiocarbon atoms.The raw radiocarbon date of any sample can then be converted to true date by using this calibration table.This calibration step eliminates any concern about fluctuations in historic radiocarbon to stable carbon ratios or decay rates.