Radioactive age dating definition
Relative dating helps determine what came first and what followed, but doesn't help determine actual age.Radiometric dating, or numeric dating, determines an actual or approximate age of an object by studying the rate of decay of radioactive isotopes, such as uranium, potassium, rubidium and carbon-14 within that object. This rate provides scientists with an accurate measurement system to determine age.
In a related article on geologic ages (Ages), we presented a chart with the various geologic eras and their ages.
Radiometric dating is self-checking, because the data (after certain preliminary calculations are made) are fitted to a straight line (an "isochron") by means of standard linear regression methods of statistics.
The slope of the line determines the date, and the closeness of fit is a measure of the statistical reliability of the resulting date.
Dating schemes based on rates of radioactivity have been refined and scrutinized for several decades.
The latest high-tech equipment permits reliable results to be obtained even with microscopic samples.