Carbon dating explained for kids
Other corrections must be made to account for the proportion of throughout the biosphere (reservoir effects).
Additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests done in the 1950s and 1960s.
The Mayan calendar used 3114 BC as their reference.
Isotopes are atoms with the same number of protons and electrons, but a different number of neutrons. These are the elements that we see around us and find in nature. Radioactivity is measured using a unit called the "curie". The curie measures how many atoms spontaneously decay each second. There are three main types of radiation or radioactive decay depending on the isotope. When isotopes are unstable they emit energy in the form of radiation.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.