Different cultures around the world record time in different fashions.
According to the Gregorian calendar, it is the year 2009 AD. The Kaliyuga Hindu Calendar maintains it is 5110, the Islamic calendar 1430 and the Persian, 2630.
Smallest Detectable Amount of Radiocarbon Sensitive instruments called acceleration mass spectrometers (AMS) are used to count the C/C ratio in a sample drops below 0.001 p MC?
One can estimate this time by dividing 100 p MC by 2 repeatedly until the resulting number drops below 0.001 p MC.
There are two major assumptions that are impossible to prove or disprove. Based upon the Big Bang theory as well as the theory of evolution, most scientists (and therefore the general public) believe that the universe and the world are billions of years old.
This assumption allows for C in the environment is mostly constant.
It takes another 5,730 for half of the remainder to decay, and then another 5,730 for half of what's left then to decay and so on.
The period of time that it takes for half of a sample to decay is called a "half-life." Radiocarbon oxidizes (that is, it combines with oxygen) and enters the biosphere through natural processes like breathing and eating.
It is naturally unstable and so it will spontaneously decay back into N-14 after a period of time.
It takes about 5,730 years for half of a sample of radiocarbon to decay back into nitrogen.
However, these excessively long ages are easily explained within the biblical worldview, and C should be present in specimens that are even a little more than 100,000 years old!