The Advances in Age Calculation
Discovering the age of a person simply requires asking. Determining the age of an animal or plant comes about through careful examination of the body structure. Calculating the age of those things which have already died poses an even greater challenge. Scientists have developed several techniques for accomplishing this, and the most common is radiometric dating.
The general concept behind radiometric dating is that isotopes occur in certain concentrations and degrade at a constant rate. This rate is called a half-life, and the number of half-life's elapsed indicates the approximate age of the item. The specific isotopes measured and methods by which they are measured varies. Comparing the results of these various techniques ensures that the dating is accurate.
Science was previously bound to studying those things that occur in the present. The advent of radiometric dating allows for the study of the history of Earth in a different way than any other method. Advancements in this field continue to further the field of calculating ages.