Two methods used for dating fossils


23-Sep-2016 20:24

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.

The nucleus of every radioactive element (such as radium and uranium) spontaneously disintegrates over time, transforming itself into the nucleus of an atom of a different element.

In the process of disintegration, the atom gives off radiation (energy emitted in the form of waves). Each element decays at its own rate, unaffected by external physical conditions.

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.

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).

Half-life: Measurement of the time it takes for one-half of a radioactive substance to decay.By measuring the amount of original and transformed atoms in an object, scientists can determine the age of that object.Cosmic rays: Invisible, high-energy particles that constantly bombard Earth from all directions in space.Absolute dates must agree with dates from other relative methods in order to be valid.

The most widely used and accepted form of absolute dating is radioactive decay dating. Radioactive decay refers to the process in which a radioactive form of an element is converted into a nonradioactive product at a regular rate.

Dating techniques are procedures used by scientists to determine the age of an object or a series of events.