Method of historical dating
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....
If this assumption is not true, then the method will give incorrect dates. If the production rate of C in a specimen difficult or impossible to accurately determine. Willard Libby, the founder of the carbon-14 dating method, assumed this ratio to be constant.
His reasoning was based on a belief in evolution, which assumes the earth must be billions of years old.
These cosmic rays collide with atoms in the atmosphere and can cause them to come apart.Neutrons that come from these fragmented atoms collide with C to be useful in age estimates.This is a critical assumption in the dating process.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.
Search for method of historical dating:
So, a carbon atom might have six neutrons, or seven, or possibly eight—but it would always have six protons.