While traveling to the dig site on morning, Mr. Rauluk remembers his Archeology professor giving a lecture about Radiocarbon dat
ing (Carbon dating). Carbon dating is a technique used to determine time passed after a living organism died or the age of a specimen according to the radioactivity of its remaining carbon, found in any organic matter that makes up the specimen—for example, bones, cloth, wood or plant fibers. The professor said that "All living things are made up of carbon. Some of the carbon is unstable and breaks down over time after organisms die; you can measure the unstable (radioactive) carbon levels in fossils to determine how long ago the individuals died. Carbon is the basis of life on earth and Carbon comes from the food we eat."Mr. Rauluk took a bite of his protein bar, as the van entered the dig site and he thought back to lessons he taught his students at Elevation. "There are two kinds of food sources: plant and animal. A plant combines carbon dioxide (from the air), water (from the ground), and solar energy (in the form of light with two wavelengths: 680 nm and 700 nm) to produce carbohydrates and oxygen. This process is called photosynthesis, and it is essential to all life on earth. Through photosynthesis, plants produce carbohydrates and oxygen; both are vital to sustain life for all animals, including humans. The carbohydrates provide carbon and energy; oxygen is essential in releasing the energy stored in the carbohydrates in the metabolic process."As Mr. Rauluk was getting his tools ready to continue excavating, he paused and thought back to a Chemistry lecture he heard in undergraduate school. The professor asked the class: "Did you know that a very small amount of CO2 in nature contains unstable carbon atoms and therefore is radioactive?" After a few seconds of wait time, the professor explained: "There are three kinds of carbon atoms: carbon-12, carbon-13, and carbon-14. Although C-12 and C-13 are non-radioactive and stable, C-14 is the opposite; it’s radioactive and unstable. All of these are isotopes of the same element, since they have the same number of protons (six, 6) in the nucleus and same number of electrons (six, 6) in the electron cloud of the atom; the difference in these isotopes are the number of neutrons in the nucleus of each atom. The CO2 in the atmosphere contains all of these isotopes, which is absorbed by plants and then passed the herbivores that each the plants. When animals eat each other, these isotopes are passed along the food web and radioactive C-14 can be found in all life, including humans. Since C-14 is unstable, or radioactive, the nucleus breaks down via spontaneous decay, and releases particles and energy to be in a more stable form. Through this process, C-14 gives off Beta radiation and turns into a non-radioactive N-14 atom. That being said, C-12 and C-13 are not radioactive, so they do not undergo radioactive decay".So as Mr. Rauluk continued to excavate remains as he waited in anticipation to test for the amount of remaining C-14 so he could determine the age of the remains.
