Eruption of the Laacher See volcano redated

The eruption of the Laacher See volcano in the Eifel, a low mountain range in western Germany, is one of Central Europe's largest eruptions over the past 100,000 years. The eruption ejected around 20 cubic kilometers of tephra ...

Leonardo da Vinci definitely did not sculpt the Flora bust

"It is machination, it is deception," said the director general of the Berlin Royal Museums in his defense when criticized for buying a fake. Wilhelm Bode did not budge an inch: The sculpture he acquired in 1909 was an as-yet ...

Neanderthal ancestry identifies oldest modern human genome

Ancient DNA from Neandertals and early modern humans has recently shown that the groups likely interbred somewhere in the Near East after modern humans left Africa some 50,000 years ago. As a result, all people outside Africa ...

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Carbon-14, 14C, or radiocarbon, is a radioactive isotope of carbon discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, though its existence had been suggested already in 1934 by Franz Kurie. Its nucleus contains 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method to date archaeological, geological, and hydrogeological samples.

There are three naturally occurring isotopes of carbon on Earth: 99% of the carbon is carbon-12, 1% is carbon-13, and carbon-14 occurs in trace amounts, e.g. making up as much as 1 part per trillion (0.0000000001%) of the carbon in the atmosphere. The half-life of carbon-14 is 5,730±40 years. It decays into nitrogen-14 through beta decay. The activity of the modern radiocarbon standard is about 14 disintegrations per minute (dpm) per gram carbon.

The atomic mass of carbon-14 is about 14.003241 amu. The different isotopes of carbon do not differ appreciably in their chemical properties. This is used in chemical research in a technique called carbon labeling: some carbon-12 atoms of a given compound are replaced with carbon-14 atoms (or some carbon-13 atoms) in order to trace them along chemical reactions involving the given compound.

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