Methods of dating prentice hall
The illustration below shows the three isotopes of carbon.Some isotopes of certain elements are unstable; they can spontaneously change into another kind of atom in a process called “radioactive decay.” Since this process presently happens at a known measured rate, scientists attempt to use it like a “clock” to tell how long ago a rock or fossil formed.
His reasoning was based on a belief in evolution, which assumes the earth must be billions of years old.
It cannot be used directly to date rocks; however, it can potentially be used to put time constraints on some inorganic material such as diamonds (diamonds could contain carbon-14). Cosmic rays from outer space, which contain high levels of energy, bombard the earth’s upper atmosphere.
These cosmic rays collide with atoms in the atmosphere and can cause them to come apart.
The variation is certainly partially the result of a change in the cosmic ray production rate of radiocarbon.
The cosmic-ray flux, and hence the production rate of C-14, is a function not only of the solar activity but also of the magnetic dipole moment of the Earth.4Though complex, this history of the earth’s magnetic field agrees with Barnes’ basic hypothesis, that the field has always freely decayed....