Attempt to Affect the Apparent 14C Age of Cotton by Scorching in a CO2 Environment

Abstract

One explanation for the radiocarbon dates on the Shroud of Turin being younger than the time of Christ is that the heat from a fire, which scorched a portion of the Shroud, may have affected the 14C content (dates) on the shroud by affecting molecular exchange between the fabric and atmospheric carbon. This report describes a laboratory test on the susceptibility of cellulose, in the form of cotton, to incorporate carbon from CO2 while it is heated in a closed tube with carbon dioxide until the cotton considerably darkened. To maximize the effect of this hypothetical process, we simulated the shroud material with cotton that had a 14C level of 0.55 modern (55 pMC, equivalent to 4800 yr), and the atmosphere with pure CO2, which had a 14C level of 1.3 modern (130 pMC). No measurable 14C transferred from the gas phase to the solid phase. The implication of this test is that scorching is an unlikely mechanism to affect the apparent age of cellulose-like material.