(University of Chicago Press) and touched off a total reappraisal of ancient history and prehistory known as the "radiocarbon revolution." Libby later received a Nobel Prize for his pioneering work in this new dating method.
The controversy centers upon the accuracy of these paleointensity measurements derived from rocks, sediments, and artifacts.
Barnes contends that the only accurate measurement of the earth's dipole moment is through actual observatory measurements that are averaged on a worldwide basis.
For example, an associate professor of geology at Calvin College, Davis Young, has devoted a whole chapter in his latest book to pointing out the flaws in the magnetism method of determining the age of our planet.
Three pages in this thirty-four-page work are devoted to rebutting Davis Young's critique of Thomas Barnes's model for the decay of the earth's magnetic field.
While the magnetic forces are very complex and are continually in a state of flux, we can clearly identify the main component of the total magnetic field, and it is called the dipole field.
The other components, which are lumped under the nondipole field, comprise only a fraction of the total magnetic field.
Equations can be developed for the continuous decrease In intensity, or "decay of the earth's magnetic field," as Barnes calls it. Assuming a more or less constant "decay rate," one can estimate what the intensity of the magnetic field was at any time in past history by means of extrapolation from present conditions.
According to the equations used by Barnes, the strength of the earth's magnetic moment would have been fifty thousand times greater some twenty thousand years ago than what it presently is.
One purpose for the development of the magnetism method of dating was to explain why radiocarbon dates are in direct conflict with the early Biblical dates.