Radiometric dating and radiocarbon dating
Plants obtain all their carbon atoms from the atmosphere.
is a technique used by scientists to learn the ages of biological specimens – for example, wooden archaeological artifacts or ancient human remains – from the distant past.
Carbon combines with other elements in complex ways to form the molecules that make up our bodies.
Most carbon on Earth is not radioactive, but a very small percentage is.
The results provide conclusive evidence that the linen of the Shroud of Turin is mediaeval.
Subsequently the shroud was made available for scientific examination, first in 19 by a committee appointed by Cardinal Michele Pellegrino .This is because the amount and strength of cosmic radiation entering the earth's atmosphere has varied over time.