On This Day in Science History -- December 17 -- Carbon 14 Dating
December 17th is Willard Libby's birthday. Libby was the American physical chemist who developed the carbon-14 dating technique. This method is used to determine the age of 'once living' objects up to approximately 50,000 years.
Carbon 14 is an isotope of carbon that is created naturally in the atmosphere by cosmic rays which in turn is breathed by living things or absorbed by plants. Over a lifetime of breathing, plants and animals maintain a natural ratio of carbon-14 to carbon-12. When the living thing dies, it stops absorbing the carbon-14 from the air.
147N + 10n → 146C + 11H
Carbon-14 decays into nitrogen by beta decay over time, but the process takes a long time. The half life of carbon-14 is 5,720 years, meaning after 5,720 years, the organism will have half the carbon-14 levels it did when it was alive. If you measure the amount of carbon-14 in a once living object, you can determine the approximate age of the organism.
Find out what else occurred on this day in science history.
Carbon 14 is an isotope of carbon that is created naturally in the atmosphere by cosmic rays which in turn is breathed by living things or absorbed by plants. Over a lifetime of breathing, plants and animals maintain a natural ratio of carbon-14 to carbon-12. When the living thing dies, it stops absorbing the carbon-14 from the air.
147N + 10n → 146C + 11H
Carbon-14 decays into nitrogen by beta decay over time, but the process takes a long time. The half life of carbon-14 is 5,720 years, meaning after 5,720 years, the organism will have half the carbon-14 levels it did when it was alive. If you measure the amount of carbon-14 in a once living object, you can determine the approximate age of the organism.
Find out what else occurred on this day in science history.
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