Radiocarbon Dating Founded on a false belief that levels of carbon isotopes never vary, initial radiocarbon dates were commonly off by hundreds of years.
Because wood can be dated directly and by radiocarbon, scientists used bristlecone pines to calculate a new calibration curve, and convert radiocarbon results into accurate calendar dates.
Greatly simplified, the process samples living and dead trees in a given area.
The tree-ring patterns are matched, and laid down in series, building a continuous timeline of known dates.
The most significant problem is that of biological alteration of materials in the soil. To produce an error of 50 percent in the age of a 10,000 year old specimen would require the replacement of more than 25 percent of the carbon atoms.
For a 40,000-year-old sample, the figure is only 5 percent, while an error of 5000 years can be produced by about 1 percent of modern materials.
Possible variations in the size of the exchange reservoir under glacial climates are unimportant.
Purpose To determine the absolute age of wood and organic artifacts.
Method A scientific date is either absolute (specific to one point in time) or relative (younger or older than something else).
By the application of some very well thought-out techniques, Libby and his colleagues have actually not only identified the radiocarbon in nature, but have also made quantitative estimates thereof.
Since this carbon in the atmosphere mostly becomes attached to oxygen to form carbon dioxide, and since the carbon dioxide is ingested by plants and animals and is incorporated in their biological structures, and further, since this process stops at the time of the death of the specimen, the percentage of radiocarbon among the normal carbon atoms in its system can be used to establish the date at which the specimen stops metabolizing.7-68There is no doubt that this constitutes a very ingenious and powerful dating tool, provided only that the inherent assumptions are valid.