Calculate the age of organic samples using radiocarbon dating
Radiocarbon dating is a method used to determine the age of organic materials by measuring the content of carbon-14 (¹⁴C), a radioactive isotope of carbon. The technique is based on the fact that ¹⁴C is constantly formed in the atmosphere and is incorporated into living organisms through the food chain. When an organism dies, it stops exchanging carbon with the atmosphere, and the ¹⁴C it contains begins to decay at a known rate, known as the half-life. The half-life of ¹⁴C is approximately 5,730 years, meaning that every 5,730 years, half of the original amount of ¹⁴C in a sample will have decayed.
By comparing the remaining ¹⁴C in a sample to the amount of ¹⁴C in the atmosphere, researchers can estimate the age of the sample. This method is widely used in archaeology, anthropology, and other fields to date samples of wood, bone, textiles, and other organic materials. However, it's essential to calibrate the results, as the amount of ¹⁴C in the atmosphere has varied over time due to factors like changes in solar activity.
The calculation of radiocarbon age involves measuring the ratio of ¹⁴C to the stable isotope carbon-12 (¹²C) in a sample and comparing it to a standard reference material. The result is then adjusted for isotopic fractionation and reported as a radiocarbon age in years before present (BP), where 'present' is defined as 1950 AD.
| Sample Type | ¹⁴C/¹²C Ratio | Age (BP) |
|---|---|---|
| Fresh wood | 1.2 | 0 |
| Ancient bone | 0.5 | 5730 |