on dendrochronology of fossil trees and had ample opportunity to analyze the procedures there, and to work with Ferguson for a while. I can say on pretty firm grounds that the Bristlecone chronology before 4000bp is fraught with problems and unanswered questions. While Ferguson was alive, he never allowed anyone to analyze his original data or the bases for the many suppositions that went into the establishment of the chronology. Thus the chronology was not subjected to the normal rigors of science. This is regrettable, because I believe he was a careful and sincere scientist. Of course one could always excuse Ferguson for not revealing the bases of his decisions (for example, the most important rings in any chronology are the "missing rings" which have to be added by the investigator). But suffice to say the chronology before 4000bp is entirely dependent on C14 dates of the wood, and is thus tautologous. This does not mean it is meaningless or necessarily wrong, just that I wouldn't base too much on it. Coral dating Some coral formations apparently show a longer year in the past, of about 400 days. This is taken as a confirmation of radiometric dating, since the earth's rotation should be gradually slowing down due to the effect of the moon and tides. Here is some information that was sent to me by a proponent of this method: How does a flood explain the accuracy of "coral clocks"? The moon is slowly sapping the earth's rotational energy. The