The impact of the radiocarbon dating technique on modern man has made it one of the most significant discoveries of the 20th century.No other scientific method has managed to revolutionize man’s understanding not only of his present but also of events that already happened thousands of years ago.If you're seeing this message, it means we're having trouble loading external resources on our website.
The number at the top is how many half-lives have elapsed.
Note the consequence of the law of large numbers: with more atoms, the overall decay is more regular and more predictable.
This is calculated through careful measurement of the residual activity (per gram C) remaining in a sample whose age is Unknown, compared with the activity present in Modern and Background samples. Thus 1950, is year 0 BP by convention in radiocarbon dating and is deemed to be the 'present'.
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).
Another standard, Oxalic Acid II was prepared when stocks of HOx 1 began to dwindle. The ratio of the activity of Oxalic acid II to 1 is 1.29330.001 (the weighted mean) (Mann, 1983). There are other secondary radiocarbon standards, the most common is ANU (Australian National University) sucrose.
The ratio of the activity of sucrose with 0.95 Ox was first measured by Polach at 1.50070.0052 (Polach, 1976b:122).
A chlorofluorocarbon (CFC) is an organic compound that contains only carbon, chlorine, and fluorine, produced as volatile derivative of methane, ethane, and propane.
They are also commonly known by the Du Pont brand name Freon.
The most common representative is dichlorodifluoromethane (R-12 or Freon-12).