3 methods of radiometric dating
Despite this, the momentum gained in the two decades prior to 1972 has made 4.5 b.y.
a popularly accepted “universal constant” even though the foundations on which it was based have been virtually removed.
The simplest form of isotopic age computation involves substituting three measurements into an equation of four variables, and solving for the fourth.
The equation is the one which describes radioactive decay: If one of these assumptions has been violated, the simple computation above yields an incorrect age.
(For brevity's sake, hereafter I will refer to the parent isotope as ).
In addition, it requires that these measurements be taken from several different objects which all formed at the same time from a common pool of materials.
Isochron methods avoid the problems which can potentially result from both of the above assumptions.
By comparing fossils of different primate species, scientists can examine how features changed and how primates evolved through time.
As we pointed out in these two articles, radiometric dates are based on known rates of radioactivity, a phenomenon that is rooted in fundamental laws of physics and follows simple mathematical formulas.
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.
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.