Is carbon 14 dating reliable fast dating lisa
However, the carbon-14 already in your body starts to decay. Since we know more or less how much carbon-14 you started with, counting how much you have will tell us how long ago you died.
An example, with completely made-up numbers: Say that the standard for living things is that 10% of their carbon is carbon-14 (this is way too high, but it makes the numbers easier).
We know that the decay rate of carbon, which has a half life of 5730 years.
So when we sample a specimen and find out how much radiocarbon there is left, we can use the decay rate to find out quite precisely when that organism died.
These depend on tracking the decay of some radioactive substance at a known rate (the half-life of the substance) against some known start point.It is radioactive, meaning that it slowly decays (and turns into nitrogen).The air is full of a more-or-less constant amount of carbon-14, and plants take it up via photosynthesis; animals eat that plant and acquire the same levels of carbon-14 (and carnivores eat herbivores and acquire carbon-14 as well).Once the organism dies there is no new carbon-14 being cycled into the cells and knowing the rate of decay (half life) of carbon-14 you are able to work back to an approximate date of death.Many human activities such as coal power plants and nuclear testing have increased the amount of carbon-14 in the environment.
Carbon-14 breaks down into carbon-12 in a predictable, logarithimic rate.