Is carbon 14 dating reliable
Thus, all living things on earth at any given moment contain about the same amount of carbon-14.When you die and stop eating, that amount of carbon-14 is locked in - you don't take any more into your body.Within that 50,000 year range, however, radiocarbon dating is very accurate.To find the age of things older than that we would need a different radiometric dating method Carbon-14 is a type of carbon (a very common element) with 8 neutrons.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.So looking at things like rock and organic material that take carbon in when they're formed, if we check how much carbon 14 they have now, we can form a pretty good measure of how old they are.(The further back, the less carbon 14 is found)Being able to make that calcination depends a lot on knowing how much carbon 14 was about when the material formed in the first place.
This may make it sound like a bad deal, but it's also important to note these measurements are generally not used in isolation, but in combination with other dating techniques, which both allow us to build confidence (they tend to line up well in a predictable fashion, which we wouldn't expect with random results) and also discard outliers (like if some event totally messed up the results, we can see the discrepancy and discard the bad finding).We've been doing this for a long time, and have a huge set of data about carbon-14 and how to measure it.It doesn't work further back than 50,000 years or so, since anything older than that has very little carbon-14 left in it, but new techniques are extending that date range further back.Its reliability is not perfect, but most of the time isn't off by more than 3-5%.
The rarer form of carbon "carbon 14" is unstable and decays in a predictable way over time.But carbon-14 also has natural fluctuations due to volcanoes or interaction of cosmic rays with nitrogen in the atmosphere.