malaysia mp datin datin hot photos - Bomb pulse dating
Carbon-14 was discovered on 27 February 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, California.Its existence had been suggested by Franz Kurie in 1934. The primary natural source of carbon-14 on Earth is cosmic ray action on nitrogen in the atmosphere, and it is therefore a cosmogenic nuclide.
One of the frequent uses of the technique is to date organic remains from archaeological sites.
Plants fix atmospheric carbon during photosynthesis, so the level of C level for the calculation can either be estimated, or else directly compared with known year-by-year data from tree-ring data (dendrochronology) up to 10,000 years ago (using overlapping data from live and dead trees in a given area), or else from cave deposits (speleothems), back to about 45,000 years before the present.
However, local variations in the 14C specific activity of air and foodstuffs occur, which are caused by natural processes as well as by various human activities.
As 14C enters the human body mainly through the diet,...
The marine component of the diet is believed to be of particular importance due to the non-equilibrium in 14C specific activity between the atmosphere and aquatic reservoirs during the bomb pulse.
This article reviews the 14C concentration in marine foodstuffs during the bomb-pulse era, and models how the marine component in one’s diet can affect the precision of bomb-pulse dating of human material.
When cosmic rays enter the atmosphere, they undergo various transformations, including the production of neutrons.
The resulting neutrons ( but attempts to directly measure the production rate in situ were not very successful.
Liquid scintillation counting is the preferred method.