But in December, 1956, the National Geographical Society m conjunction with the Smithsonian Institution made it known that excavations at La Venta proved by radiocarbon that the classical period of the Meso-American civilizations (Olmec, Toltec, Maya, etc.) needs to be pushed back by a full thousand years and ascribed not to the 4th to 8th centuries of the Christian era but to the 8th to 4th centuries before that era.
With these three confirmations (time the Ice Age ended, time petroleum was deposited, time of the classical period of the Meso-American civilizations), my Worlds in Collision received very substantial confirmations.
In Worlds in Collision I claimed that the time since the last glaciation needs to be drastically shortened: the figure considered valid in 1950, the year Worlds in Collision was published, was still Lyells of 100 years earlier, namely 35 thousand years. previously this maximum advance had been assumed to date from about 25,000 years ago, actually 35,000 if one looks up the literature of the time. found that, as I also claimed, another advance of ice took place only 3,500 years ago.
Libby found (and I quote Frederick Johnson, who participated in his volume, Radiocarbon Dating) that the advance of the ice occurred about 1 1,000 years ago . A few years later Rubin and Suess of the Geological Survey of the U. The second confirmation came concerning the age of the petroleum. The surprising fact was that oil was found there in Recent sediment and must have been deposited during the last 9,200 years. (Emphasis added.) Actually I asked Libby whether he would see to it that petroleum should be subjected to tests and it was he who drew my attention to the work done by Smith.
Therefore the claim was made that the magnetosphere around the earth, discovered in 1958, suffered occasional weakening, thus allowing more cosmic rays to pass it and to hit the nitrogen atoms in the upper atmosphere, changing them to radiocarbon.
It was further claimed that the magnetic field of the earth might have reversed its polarity in the last 40 thousand years, a phenomenon known to have happened in geological epochs.
Now let us review in the light of research in cosmic catastrophism the correctives that, in our view, need to be introduced into the method.
However, three or four rings formed in one year is not uncommon, especially if the tree grows on a slope, with the ground several times in a year turning wet and dry because of rapid outflow of water (Glueck et al., Botanical Review, 7, 649-713; and 21, 245-365).Speaking of my research as far as it affects the radiocarbon dating method, I would like to separate the finds concerning natural events (Worlds in Collision, Earth in Upheaval) from finds concerning the true chronology of Egypt and of the ancient World in general (Ages in Chaos).Libbys discoveries, published in 1952, gave immediate support and even vindication to three independent conclusions of my research into natural events of the past.But as the method was refined, it started to show rather regular anomalies.First, it was noticed that, when radiocarbon dated, wood grown in the 20th century appears more ancient than wood grown in the 19th century.If such reversals were not instantaneous but required thousands of years, the atmosphere during that time would not be shielded from cosmic rays and substantially more of them would reach it.However, the scientific literature of the last few decades did not contain any reference to a reversal observed on human artifacts like pottery though a paper by Manley in 1949 (Science News, Penguin Publication) told of the work of G.But I could not and should not satisfy myself with this support without repaying by demonstrating where the difficulties and pitfalls of the method are hidden.In the cataclysmic events reconstructed in Worlds in Collision and also those that preceded the fall of the Middle Kingdom in Egypt, various effects could not but vitiate the radiocarbon performance, some of these effects tending to make organic life appear older than its actual age, and others making it appear more recent.Folghereiter done at the turn of the century on Attic and Etruscan pottery: he found that the polarity was reversed in the eighth century before the present, era.To determine the extent of correction necessary to render the radiocarbon method reliable, dendrochronologists devised a plan to control the radiocarbon dates by building a chronology of tree rings of the white bristlecone pine, the longest living tree.