Carbon-14 Dating: An Invaluable Yardstick in the Chronology of Humans
Archaeologists utilize several methods to analyze data from the past. One scientific tool helps to analyze the radioactive decay of chemical elements found in plant and animal remains, pottery, and even rocks. Radiocarbon dating, also known as carbon-14 dating, has developed into one of the most important radioisotope dating methods archaeologists employ. This scientific tool, first developed by Willard F. Libby in the late 1940s, began with the discovery of the isotopic carbon-14 atom. Following this discovery, scientists began to ponder ways to utilize carbon-14 to date previously living organisms. Since scientists knew that living organisms absorb carbon-14 at a constant rate while alive, they started to formulate a process to measure C-14 to C-12 ratios in dead organisms. This procedure made it possible for scientists to age an organism using this carbon ratio. To ensure the formula was correct, they began to perform experimental trials of radiocarbon dating to test its accuracy, and while testing, discovered several methods of carbon 14 dating that yielded accurate results including the Geiger counting method, liquid scintillation method, and AMS dating method. These three methods have significantly improved the accuracy of assigning dates to past events and artifacts, dating as far back as 70,000 years. Using and describing the techniques, procedures, and applications, the anthropological school of thought for carbon-14 dating will be derived. Although this method has drawbacks and critics, carbon-14 dating has shaped and influenced the historical classification artifacts to the point that archaeologists, geologists, and anthropologists now have the ability to construct the world’s history by filling in some of the many blank dates in the chronology of the history of our human world and by substantiating and revising other dates. The foundation of radiocarbon dating began with scientist Williams F. Libby and, throughout history, has evolved into a valid dating technique proved through several experiments. Carbon-14 dating emerged in 1941, when scientists isolated and discovered the radioactive atom, carbon-14. Utilizing this discovery of the unstable radioactive isotope of carbon, Libby formulated an idea for using the decay rate of this radioactive form of carbon to date the remains of once-living plants and animals using discovered charcoal, wood, bone, shells, and fossils from the past. In 1948, while at the University of Chicago, he and his colleagues started experimenting with carbon-14 as a means for dating the past. The scientists proved that carbon-14, which is present in our atmosphere as carbon dioxide, is absorbed by plants, animals, and human beings at a constant rate; thus, organisms contain a constant amount of carbon-14 throughout their lifespan. A living organism can only intake a certain amount of carbon-14, and since the ratio of C-14 to C-12 in a living organism is approximately 1.35x10-12, scientists can assume the amount of carbon-14 an organism absorbs. Then, at the moment the living organism dies and stops respiring, the carbon-14 remaining in the organism starts to disintegrate at the half-life rate of 5,568 years (Poole 1961:27). Today, based on refined calculations/techniques the half-life rate of carbon-14 is generally considered to be 5,730 years (Wheatley 2004:98; DeYoung 2005:46). From the experimental results, Libby devised an apparatus to measure the amount of carbon-14 that had been lost and the amount that remained in the substance. He planned to calculate the age of an object from the amount of carbon-14 remaining after death. To test the validity of his carbon-14 counting device and subsequent calculations, Libby tested many items that archaeologists had previously dated. Some of the items he tested included: acacia wood from the first stepped pyramid tomb of Egyptian ruler Zoser (established date: 2700-2600...
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