Shroud of turin carbon dating controversy
A poster advertising the 1898 exhibition of the shroud in Turin.
Secondo Pia's photograph was taken a few weeks too late to be included in the poster.
In the next stage, the graphite derived from the shroud sample, consisting of a mixture of stable carbon isotopes with radioactive carbon 14, was bombarded by heavy cesium atoms.
This process knocked carbon atoms loose from the graphite, endowed some of them with electric charges and sent them toward the accelerator.
Scholars debate its existence previous to 1390, describing the period before that as “very murky territory.” Even during the middle ages there was disagreement over authenticity of the cloth, with written claims at the time between church officials suggesting it was a forgery.
In the technique used by all three institutions, carbon and other atoms and molecules extracted from the sample are electrically charged and hurled through a series of magnetic fields by a special nuclear accelerator, called a tandem accelerator mass spectrometer.
These fields deflect atoms of varying mass and electrical charge so they strike different regions of a detector target.
By passing accelerated carbon atoms through argon gas, the instrument next stripped electrons from the carbon atoms, thereby giving them positive charges.
In the process, ''background'' molecules having the same masses as carbon atoms were removed, eliminating a potential source of error.