The age of the remains of plants, animals, and other organic material can be determined by measuring the amount of carbon-14 contained in that material.
Carbon-14, a radioactive form of the element carbon, is created in the atmosphere by cosmic rays (invisible, high-energy particles that constantly bombard Earth from all directions in space).
The older the pottery, the brighter the light that will be emitted.
Using thermoluminescence, pottery pieces as old as 100,000 years can be dated with precision. Known as dendrochronology (pronounced den-dro-crow-NOL-o-gee), tree-ring dating is based on the fact that trees produce one growth ring each year.
With sensitive instrumentation, this range can be extended to 70,000 years.
In addition to the radiocarbon dating technique, scientists have developed other dating methods based on the transformation of one element into another.
These include the uranium-thorium method, the potassium-argon method, and the rubidium-strontium method. Thermoluminescence (pronounced ther-moeloo-mi-NES-ence) dating is very useful for determining the age of pottery.
Absolute dating methods are carried out in a laboratory.
Before the advent of absolute dating methods in the twentieth century, nearly all dating was relative.
The main relative dating method is stratigraphy (pronounced stra-TI-gra-fee), which is the study of layers of rocks or the objects embedded within those layers.
Dating techniques are procedures used by scientists to determine the age of an object or a series of events.
The two main types of dating methods are relative and absolute.