The basis of radiocarbon dating is simple: all living things absorb carbon from the atmosphere and food sources around them, including a certain amount of natural, radioactive carbon-14. When the plant or animal dies, they stop absorbing, but the radioactive carbon that theyve accumulated continues to decay.

How do they date carbon-14?

Carbon-14 dating, also called radiocarbon dating, method of age determination that depends upon the decay to nitrogen of radiocarbon (carbon-14). Because carbon-14 decays at this constant rate, an estimate of the date at which an organism died can be made by measuring the amount of its residual radiocarbon.

How long is carbon-14 effective for dating?

Because the half-life of carbon-14 is 5,700 years, it is only reliable for dating objects up to about 60,000 years old.

How reliable is carbon 14 dating?

To radiocarbon date an organic material, a scientist can measure the ratio of remaining Carbon-14 to the unchanged Carbon-12 to see how long it has been since the materials source died. Advancing technology has allowed radiocarbon dating to become accurate to within just a few decades in many cases.

What are the limits of carbon-14 dating?

The diminishing levels via decay means that the effective limit for using c14 to estimate time is about 50,000 years. After this time, there is little if any c14 left. Subsequent work has shown that the half-life of radiocarbon is actually 5730 ± 40 years, a difference of 3% compared to the Libby half-life.

What are two limits to using carbon 14 dating?

Radiocarbon dating is therefore limited to objects that are younger than 50,000 to 60,000 years or so. (Since humans have only existed in the Americas for approximately 12,000 years, this is not a serious limitation to southwest archaeology.) Radiocarbon dating is also susceptible to contamination.