Information in the Shroud of Turin About Its Variable Molecular Properties

Three earlier papers on the Shroud of Turin showed that ultraviolet induced fluorescence (UVIF) intensity is non-uniform over the surface of the Shroud. These intensity results were based on an analysis of UVIF photographic images taken in 1978 as part of a scientific investigation of the Shroud. In this paper the statistical technique, principal component analysis (PCA), is used to analyze the information present in the UVIF images. It is shown that the vast majority of information in the UVIF Shroud images is contained in their International Commission on Illumination (CIE Lab) image intensity. Differences in UVIF intensity indicate differences in the Shroud’s molecular properties. Such differences can be due to differences in molecular structure, contamination, and burned regions. Fluorescence spectral results published as part of the same 1978 scientific study confirm the intensity variation with position of the UVIF images. These spectral fluorescence results are discussed in detail. The combined photographs and spectral results demonstrate that color contributes relatively little to the information in the UVIF images. One possible cause of the variation of UVIF intensity, namely neutron radiation, is briefly discussed. Charred Shroud material, collected during its cleaning in 2002, can be used to assess whether the Shroud was exposed to neutron radiation. Such testing would be completely non-destructive to the Shroud. New UVIF photographs need to be taken to validate the results discussed in this paper.