Teaching the methods of absolute dating

This technique is based on the principle that all objects absorb radiation from the environment.

This process frees electrons within minerals that remain caught within the item.

However, it can be used to confirm the antiquity of an item.The development of accelerator mass spectrometry (AMS) dating, which allows a date to be obtained from a very small sample, has been very useful in this regard.Other radiometric dating techniques are available for earlier periods.The relatively short half-life of carbon-14, 5,730 years, makes dating reliable only up to about 50,000 years.The technique often cannot pinpoint the date of an archeological site better than historic records, but is highly effective for precise dates when calibrated with other dating techniques such as tree-ring dating.

Carbon-14 moves up the food chain as animals eat plants and as predators eat other animals. It takes 5,730 years for half the carbon-14 to change to nitrogen; this is the half-life of carbon-14.