This represents the ideal date for the amount of 14C measured for the sample.However, as the quantity of 14 absorbed by all life fluctuates from year to year, the figure must be calibrated based on known fluctuation.It is used in dating things such as bone, cloth, wood and plant fibers that were created in the relatively recent past by human activities.
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.
Because the time it takes to convert biological materials to fossil fuels is substantially longer than the time it takes for its in the atmosphere, which attained a maximum in 1963 of almost twice what it had been before the testing began.
At an archaeological dig, a piece of wooden tool is unearthed and the archaeologist finds it to be 5,000 years old.
A child mummy is found high in the Andes and the archaeologist says the child lived more than 2,000 years ago.
The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire in a sample from a dead plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died.