Science of carbon dating how to not be intimidating to guys
The physics, chemistry, and biology, behind carbon dating is absolutely fascinating and worth knowing. Earth is constantly being bombarded with cosmic radiation, which are highly energetic, charged particles that originate from stellar disturbances, like solar flares and supernovae.
Some of these particles collide with atmospheric nitrogen and knock off one of its protons.
The term ‘half-life’ refers to the amount of time it takes for half of a sample’s radioactive isotopes to turn into a stable isotopes.
We can determine the half life of an isotope by measuring how much radiation a sample produces over a given time period from a known number of radioactive atoms.
Most carbon consists of the isotopes carbon 12 and carbon 13, which are very stable.
A very small percentage of carbon, however, consists of the isotope carbon 14, or , which is unstable.
Carbon 14 has a half-life of 5,780 years, and is continuously created in Earth's atmosphere through the interaction of nitrogen and gamma rays from outer space.
Because atmospheric carbon 14 arises at about the same rate that the atom decays, Earth's levels of carbon 14 have remained fairly constant.
He first noted that the cells of all living things contain atoms taken in from the organism's environment, including carbon; all organic compounds contain carbon.
Once an organism is dead, however, no new carbon is actively absorbed by its tissues, and its carbon 14 gradually decays.
Libby thus reasoned that by measuring carbon 14 levels in the remains of an organism that died long ago, one could estimate the time of its death.
What do you get when you subtract one proton from nitrogen? But not any old carbon – you get a radioactive form called carbon-14 (the number ’14’ is the number of protons and neutrons the isotope has).
During photosynthesis plants turn carbon dioxide into sugar.
Limestone (calcium ate) can introduce much older carbon to a sample giving it the appearance of age.