When objects of the Old Kingdom and Middle Kingdom of Egypt yielded carbon dates that appeared roughly comparable with the historical dates, Libby made his method known.
With initial large margin of error and anything that did not square with expectation, judged as contaminated, the method appeared to work and was hailed as completely reliablejust as the atomic clock is reliableand this nobody doubted.
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.
As years passed and more tests were made (soon by laboratories counted in scores), a rather consistent deviation between radiocarbon age and historical age started to receive the attention of researchers.
The radiocarbon dates diverge from the historical dates by several hundred years (often 500 to 700), and, interestingly, in the Egyptian samples more so than in samples from most other ancient civilizations.
Suess explained the phenomenon by the fact that the increased industrial use of fossil carbon in coal and in oil changed the ratio between the dead carbon C12 and the C14 (radiocarbon) in the atmosphere and therefore also in the biosphere.
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.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.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.We must also evaluate the basic reliance on Egyptian chronology that, as we shall see, needs to be discontinued.This led Libby to write in 1963: The data [in the Table] are separated into two groups Egyptian and non-Egyptian. The combined efforts of several researchers led them to believe that one of the conditions stipulated by Libby for a flawless functioning of his method was not historically sustained; it is claimed that the influx of cosmic rays varied with time.This separation was made because the whole Egyptian chronology is interlocking and subject to possible systematic errors . . Also, Egyptian historical dates beyond 4000 years ago may be somewhat too old, perhaps 5 centuries too old at 5000 years ago. Yet, since this influx comes from many sources, the sun being only one of them, sunspot activity could be related to the variation only in a very limited degree.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.The correctness of the method depends greatly on the condition that in the last 40 or 50 thousand years the quantity of water in the hydrosphere (and carbon diluted in it) has not substantially changed. The method depends also on the condition that during the same period of time the influx of cosmic rays or energy particles coming from the stars and the sun has not suffered substantial variations.To check on the method before applying it on various historical and paleontological material, Libby chose material of Egyptian archaeology, under the assumption that no other historical material from over 2,000 years ago is so secure as to its absolute dating.