See Renfrew for more details. How do you reply? Now if the magnetic field several thousand years ago was indeed many times stronger than it is today, there would have been less cosmic radiation entering the atmosphere back then and less C would have been produced.
About the Author s: Many archaeologists were skeptical when Ferguson's calibration with bristlecone pines was first published, because, according to his method, radiocarbon dates of the Western megaliths showed them to be much older than their Near-Eastern counterparts. Hence at least some of the missing rings can be found. If anything, the tree-ring sequence suffers far more from missing rings than from double rings. National Center for Science Education, Inc. Stonehenge fits the heavens as they were almost four thousand years ago, not as they are today, thereby cross-verifying the C dates.