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.
In 1779, Swedish scientist Carl Scheele showed that graphite burned to form carbon dioxide and so must be another form of carbon.
In 1796, English chemist Smithson Tennant established that diamond was pure carbon and not a compound of carbon; it burned to form only carbon dioxide.
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.
Lavoisier noted the overall weight of the jar was unchanged and that when it burned, the diamond had combined with oxygen to form carbon dioxide.
He concluded that diamond and charcoal were made of the same element – carbon.
Aside from radiocarbon dating, ISO/IEC 17005-accredited Beta Analytic also provides biobased/renewable carbon content testing to manufacturers, product distributors, and researchers worldwide for biobased products, biofuels, waste-derived fuels and their combustion emissions (CO2 gas).
The lab also uses Carbon-14 analysis for natural product source testing on materials such as flavors, fragrances, essential oils, cosmetics and supplements to identify petrochemicals.
In 1772 he pooled resources with other chemists to buy a diamond, which they placed in a closed glass jar.