Carbon 14 nitrogen 14 dating
The rate at which the regeneration takes place has gone virtually unchanged for centuries; a feature which depends on the flux of particles bombarding the earth, and the strength of the magnetic field capable of diverting them.This magnetic shield, and consequently the particle flux, has slowly changed over time, and the quantity of carbon 14 formed on Earth changes with it.Human remains, fossils and organic materials from archaeological sites are all dated using carbon-14.Books, clothing and food remains are all archaeological artifacts that can be carbon dated.This radioactive isotope of carbon is called radiocarbon.The carbon 14 found in nature is constantly being regenerated by cosmic rays hitting the atmosphere.
After 5,730 years, the amount of carbon 14 left in the body is half of the original amount.At any particular time all living organisms have approximately the same ratio of carbon 12 to carbon 14 in their tissues.When an organism dies it ceases to replenish carbon in its tissues and the decay of carbon 14 to nitrogen 14 changes the ratio of carbon 12 to carbon 14. Carbon-14 dating can be used on objects ranging from a few hundred years old to 50,000 years old. Libby and others (University of Chicago) devised a method of estimating the age of organic material based on the decay rate of carbon-14.