How do scientist do carbon dating
Archaeology and other human sciences use radiocarbon dating to prove or disprove theories.
Over the years, carbon 14 dating has also found applications in geology, hydrology, geophysics, atmospheric science, oceanography, paleoclimatology and even biomedicine.
Plants and animals assimilate carbon 14 from carbon dioxide throughout their lifetimes.
When they die, they stop exchanging carbon with the biosphere and their carbon 14 content then starts to decrease at a rate determined by the law of radioactive decay.
Gas proportional counting is a conventional radiometric dating technique that counts the beta particles emitted by a given sample. In this method, the carbon sample is first converted to carbon dioxide gas before measurement in gas proportional counters takes place.
Liquid scintillation counting is another radiocarbon dating technique that was popular in the 1960s.
Scientists can determine how long ago an organism died by measuring how much carbon-14 is left relative to the carbon-12.
Carbon-14 has a half life of 5730 years, meaning that 5730 years after an organism dies, half of its carbon-14 atoms have decayed to nitrogen atoms.
Similarly, 11460 years after an organism dies, only one quarter of its original carbon-14 atoms are still around.
Radiocarbon present in molecules of atmospheric carbon dioxide enters the biological carbon cycle: it is absorbed from the air by green plants and then passed on to animals through the food chain.
Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food.