The ratio of14C to 12C in living creatures is about one 14C atom for every 1 trillion 12C atoms.
When an organism dies, this ratio (1 to 1 trillion) will begin to change.
A favorite tactic of Young-Earthers involves citing studies which show trace amounts of Indeed, this results from a unique decay mode known as "cluster decay" where a given isotope emits a particle heavier than an alpha particle (radium-226 is an example.) This fact is extremely inconvenient and creationist literature, accordingly, usually does not mention it.
Carbon-dating Carbon dating, like other radiometric dating methods, requires certain assumptions that cannot be scientifically proved.
The amount of 12C will remain constant, but the amount of 14C will become less and less.
The smaller the ratio, the longer the organism has been dead.
Recall that atoms are the basic building blocks of matter.
The older a sample is, the less (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by this process date to around 50,000 years ago, although special preparation methods occasionally permit accurate analysis of older samples.
The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained.
Research has been ongoing since the 1960s to determine what the proportion of in the atmosphere has been over the past fifty thousand years.
Note that, contrary to a popular misconception, carbon dating is not used to date rocks at millions of years old.
Before we get into the details of how radiometric dating methods are used, we need to review some preliminary concepts from chemistry.