(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.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.It is not uncommon for a cosmic ray to collide with an atom in the atmosphere, creating a secondary cosmic ray in the form of an energetic neutron, and for these energetic neutrons to collide with nitrogen atoms.When the neutron collides, a nitrogen-14 (seven protons, seven neutrons) atom turns into a carbon-14 atom (six protons, eight neutrons) and a hydrogen atom (one proton, zero neutrons).
He is presently employed in the Space & Atmospheric Sciences Group at the Los Alamos National Laboratory.
It has become increasingly clear that these radiometric dating techniques agree with each other and as a whole, present a coherent picture in which the Earth was created a very long time ago.
Further evidence comes from the complete agreement between radiometric dates and other dating methods such as counting tree rings or glacier ice core layers.
Carbon-14 is radioactive, with a half-life of about 5,700 years.
For more information on cosmic rays and half-life, as well as the process of radioactive decay, see How Nuclear Radiation Works.