Carbon dating accurate up
The amount of cosmic rays penetrating the earth's atmosphere is itself affected by things like the earth's magnetic field which deflects cosmic rays.
Precise measurements taken over the last 140 years have shown a steady decay in the strength of the earth's magnetic field.
At least to the uninitiated, carbon dating is generally assumed to be a sure-fire way to predict the age of any organism that once lived on our planet.
Without understanding the mechanics of it, we put our blind faith in the words of scientists, who assure us that carbon dating is a reliable method of determining the ages of almost everything around us.
Specifically, each nucleus will lose an electron, a process which is referred to as decay.
This rate of decay, thankfully, is constant, and can be easily measured in terms of ‘half-life’.
Specifically, there are two types of carbon found in organic materials: carbon 12 (C-12) and carbon 14 (C-14).
When a creature dies, it ceases to consume more radiocarbon while the C-14 already in its body continues to decay back into nitrogen. This is how carbon dating works: Carbon is a naturally abundant element found in the atmosphere, in the earth, in the oceans, and in every living creature.C-12 is by far the most common isotope, while only about one in a trillion carbon atoms is C-14.So, if we find the remains of a dead creature whose C-12 to C-14 ratio is half of what it's supposed to be (that is, one C-14 atom for every two trillion C-12 atoms instead of one in every trillion) we can assume the creature has been dead for about 5,730 years (since half of the radiocarbon is missing, it takes about 5,730 years for half of it to decay back into nitrogen).If the ratio is a quarter of what it should be (one in every four trillion) we can assume the creature has been dead for 11,460 year (two half-lives).