Range of carbon dating
But the radiocarbon detected in diamonds is equivalent to ages of up to 80,000 years.
So you can see why the various age limits have appeared in different publications of ours.
You can get an idea of the relationship between C14 and age at the Carbon Dating calculator page.
1950 was chosen for no particular reason other than to honour the publication of the first radiocarbon dates calculated in December 1949 (Taylor, 19).
By knowing how much carbon 14 is left in a sample, the age of the organism when it died can be known.
It must be noted though that radiocarbon dating results indicate when the organism was alive but not when a material from that organism was used.
The Oxalic acid standard which was developed is no longer commercially available.
The older beta counting instrument was stretched to get results of 50,000 years, whereas the AMS instrument should be effective up to 95,000 years.It is rapidly oxidized in air to form carbon dioxide and enters the global carbon cycle.Plants and animals assimilate carbon 14 from carbon dioxide throughout their lifetimes.The levels of Carbon Dioxide (Co2) gas have risen to levels civilization has not seen before.The Oxalic acid standard was made from a crop of 1955 sugar beet.
When they die, they stop exchanging carbon with the biosphere and their carbon 14 content then starts to decrease at a rate determined by the law of radioactive decay.