Problems with radioactive carbon dating American ero chat
The amount of carbon-14 in the air has stayed the same for thousands of years.
There is a small amount of radioactive carbon-14 in all living organisms because it enters the food chain.
Y., reported today in the British journal Nature that some estimates of age based on carbon analyses were wrong by as much as 3,500 years.
They arrived at this conclusion by comparing age estimates obtained using two different methods - analysis of radioactive carbon in a sample and determination of the ratio of uranium to thorium in the sample.
Comparison of ancient, historically dated artifacts (from Egypt, for example) with their radiocarbon dates has revealed that radiocarbon years and calendar years are not the same even for the last 5,000 calendar years.
In last Tuesday’s lecture, radiocarbon dating was covered briefly.
Because it is radioactive, carbon 14 steadily decays into other substances.
The field of radiocarbon dating has become a technical one far removed from the naive simplicity which characterized its initial introduction by Libby in the late 1940's.
Other radiometric dating methods such as potassium-argon or rubidium-strontium are used for such purposes by those who believe that the earth is billions of years old.Later called Ötzi the Iceman, small samples from his body were carbon dated by scientists.The results showed that Ötzi died over 5000 years ago, sometime between 33 BC. It is found in the air in carbon dioxide molecules.Once an organism dies, it stops taking in carbon-14.The carbon-14 it contained at the time of death decays over a long period of time, and the radioactivity of the material decreases.
Some organic materials do give radiocarbon ages in excess of 50,000 "radiocarbon years." However, it is important to distinguish between "radiocarbon years" and calendar years.