1, definition
Fourteen-carbon dating is a method to determine the age of primitive living animals and plants by using the naturally occurring radioactive dating method of carbon isotope 14. This method can be used to date organic matter as early as 50,000 years ago, and it is an accurate archaeological dating technique.
2. Application
Archaeology, history, anthropology and archaeology are three completely different but closely related knowledge systems, which tell human beings with the help of the past. Historians can know which cultures flourished in different regions and when they declined. Anthropologists can describe people's physiological characteristics, culture, environment and social relations.
For many years, without radiocarbon dating, tree ring dating, paleomagnetism dating, luminescence dating and obsidian hydration analysis, historical and cultural information would never be known. Radiocarbon dating technology has completely changed archaeology. Carbon 14 dating is still a powerful technology, which is of great value to archaeologists and other scientists.
Principle and calibration of carbon 14 dating method;
1, principle
Under the action of cosmic rays, nitrogen 14 loses a proton while gaining a neutron, and becomes carbon 14, with 6 protons and 8 neutrons. Carbon 14 is called radioactive carbon isotope because of its special atomic structure and very unstable. Carbon 14 combines with oxygen in the air to form carbon dioxide containing carbon 14.
Due to the metabolism of organisms, including photosynthesis of plants and respiration of organisms, carbon 14 is in a dynamic equilibrium process in the whole food chain. It can be understood that in a certain period of time, the carbon 14 content in the whole biosphere is the same as that in the atmosphere at that time, and we can regard it as a stable carbon 14 environment.
Step 2 calibrate
Because the frequency of galactic cosmic rays will change, the ratio and content of C 14 in the atmosphere will also change, so the age obtained by C 14 dating has a certain gap with the real age of the sample, so the final age is not the directly measured age of C 14.