Carbon dating Essay Example

dating of artifacts, including those from Pompeii, the Dead Sea Scrolls, Stonehenge, and New Mexico. His colleagues contributed to his significant discovery of dating glacial debris in Two Creeks, Wisconsin. This finding provided compelling evidence that North America's last Ice Age occurred more recently than previously believed by geologists - around 11,000 BCE instead of the commonly accepted date of 25,000 years ago (Libby 1952:105).

Despite significant advancements in radiocarbon dating techniques, the general approach established by Libby remains widely accepted as a viable means of dating. The method relies on the radioactive properties of carbon-14, an unstable isotope of carbon-12 with two additional neutrons in its composition. Cosmic rays penetrating the earth's atmosphere and interacting with nitrogen atoms generate carbon-14.

Plants and trees absorb carbon dioxide, as well as both C-14 and C-12 during photosynthesis. The radioactive carbon-14 combines with oxygen to form carbon dioxide that contains stable carbon-12 when it descends towards the earth's surface. Once consumed by animals in various forms, the isotopes of carbon are incorporated into their tissues.

After the death of plants and animals, there is a gradual decrease in the small amount of carbon-14 present in them as it undergoes Beta decay to form Nitrogen-14 (Carbon-14 ”+ Nitrogen-14 + Beta (P)).

When determining the age of a sample, the initial carbon-14 content is compared to its current carbon-14 content and adjusted based on factors such as carbon-14's half-life and calibration (DeYoung 2005:46-48).

In order to ensure accuracy in carbon dating, scientists and archaeologists typically collect large samples to account for loss during the purification and distillation processes. The sample location's stratigraphy is also examined to verify consistency.

Trowels used for collection are cleaned thoroughly, and artifacts are packed in chemically neutral materials to prevent alteration of the C-14 to C-12 ratio. Additionally, similar tests are performed on artifacts to confirm the accuracy of calculated dates.

To determine the age of a sample, scientists carry out experimental trials by identifying and counting the number of carbon-14 atoms present in it. This process uses the distinctive physical characteristics of carbon-14 such as its larger mass and radioactivity (Hedman 2007:58).

This is a formula used to determine the elapsed time since an organism's death. It involves an exponential decay equation, A = eA(-Xk), where "A" represents the remaining carbon-14 atoms after a period of "t" time, "AO" is the initial amount of carbon-14 atoms, and "X" is the decay constant (L'Annunziata 2007:523). Scientists can use this formula to calculate the ratio between the current amount of the radioactive isotope and the original amount in relation to time.

It is crucial to note that archaeologists and scientists presume the steady production of radiocarbon in the atmosphere and constant carbon-12 to carbon-14 ratio when employing these equations. The dating system was formulated by Libby and peers in the 1940s, relying on carbon-14's radioactive nuclei decay. Geiger counters have since been used by them and other experts to detect radioactive carbon within specimens.

The Geiger counter clicks when exposed to rays, indicating the presence of radioactivity, allowing scientists to determine the historical age of the substance. In the case of determining the age of a wood piece destroyed by fire, the specimen is treated with chemicals to remove any remaining contamination particles before testing. The following step

involves isolating carbon-14 atoms from other components present in the wood by burning it in a heavy glass tube.

In the purification process of the gas produced by burning wood, carbon dioxide is emitted and collected in a vacuum system for purification. The purified gas containing carbon-14 is transferred to a glass jar and introduced into a carbon-14 counter consisting of a casing with Geiger counters arranged in a ring. The counter is shielded from atmospheric radiation by surrounding it with lead or iron bricks. The carbon-14 atoms of the sample are observed by an electronic panel that records the disintegration time of each atom.

Scientists utilize formulas discussed earlier to estimate the age of a sample by determining the number of years that have passed since carbon-14 intake ceased and decay began (Poole 1961:40-46). Liquid Scintillation counting is a second radiocarbon dating technique, which was prevalent during the 1960's. This method involves converting a sample to carbon dioxide via combustion or acid hydrolysis.

According to Higham's article, the gas is prepared for its reaction with benzene by undergoing purification. (2002, para. 2)

Certain scientists are challenging the validity of assuming a 5,730 year half-life for nuclear stability.

In the industrial era, the escalation in fossil fuel combustion led to an elevation of carbon dioxide levels and a decline in the carbon-14 to carbon-12 ratio, causing a distortion of age perception in objects.

Charged particles in cosmic rays can be redirected by magnetic fields, which affects the amount of cosmic rays that reach the Earth's atmosphere.

The radiocarbon dating process takes into account variations in magnetic fields when dating artifacts, as it is an essential factor

(IHedman 2007:75-76). Additionally, radiocarbon dating assumes that the fraction of C-14 to C-12 was equivalent in past and present organisms. However, it is known that certain living creatures can accumulate a higher amount of carbon-14, known as mass fractionation. For instance, corn exhibits 2-3% more carbon-14 during its photosynthesis compared to sugar beets or tree leaves during the same period.

In my viewpoint, despite its limitations, carbon-14 dating is an essential tool for dating artifacts. While acknowledging that the influence of corn-derived materials can lead to underestimation of the artifact's age according to Hedman (2007:68-69), experts in archaeology, geology and anthropology have a better comprehension of human history thanks to carbon-14 dating's chronological information. Although it has a limit of 70,000 years for dating artifacts, it has helped revise our understanding of human history by revealing that the Ice Age occurred only 13,000 years ago rather than 25,000 years ago.

Radiocarbon dating has contributed to the confirmation of existing dates.

Bibliography

1. 'Dating. " Encyclopaedia Britannica. 2009. Encylopaedia Britannica Online.
2. 09 Sept. 2009 . DeYoung, Don. Thousands, Not Billions: Challenging an Icon of Evolution.