# Carbon dating the process

Once an organism is decoupled from these cycles (i.e., death), then the carbon-14 decays until essentially gone.The half-life of a radioactive isotope (usually denoted by $$t_$$) is a more familiar concept than $$k$$ for radioactivity, so although Equation $$\ref$$ is expressed in terms of $$k$$, it is more usual to quote the value of $$t_$$.Fallout from nuclear bomb tests during the cold war has just yielded encouraging news for those searching for ways to reverse heart disease.

Carbon-14 is constantly be generated in the atmosphere and cycled through the carbon and nitrogen cycles.

"Everything which has come down to us from heathendom is wrapped in a thick fog; it belongs to a space of time we cannot measure.

We know that it is older than Christendom, but whether by a couple of years or a couple of centuries, or even by more than a millenium, we can do no more than guess." [Rasmus Nyerup, (Danish antiquarian), 1802 (in Trigger, 19)].

"This study shows for the first time and very clearly that there is some turnover of cardiomyocytes within the lifetime of an individual." It also lays to rest claims that heart cells turn over quickly, says Deepak Srivastava of the Gladstone Institute of Cardiovascular Disease in San Francisco, California.

To conduct the study, Frisén created his own version of radiocarbon dating.