Mechanical and opto-chemical dating of the Turin Shroud
G. Fanti, Pierandrea Malfi, F. Crosilla
The present paper discusses the results obtained using innovative dating methods based on the analysis of mechanical parameters (breaking strength, Young modulus and loss factor) and of opto- chemical ones (FT-IR and Raman). To obtain mechanical results it was necessary to build a particular cycling-loads machine able to measure the mechanical parameters of single flax fibers 1-3 mm long. A least squares multi linear regression (MLR) has been applied to the measured mechanical data estimating a TS age equal to 260 AD. Furthermore, two opto- chemical methods have been applied to test the linen fabric, obtaining a date of 250 BC by a FT-IR ATR analysis and a date of 30 AD by a Raman analysis. These two dates combined with the mechanical result, weighted through their estimated square uncertainty inverses, give a final date of the Turin Shroud of 90 AD ±200 years at 95% confidence level. While this date is both compatible with the time in which Jesus Christ lived in Palestine and with very recent results based on numismatic dating, it is not compatible with the 1988 radiocarbon measurements that should be repeated after the necessary clarifications relative to the possible environmental factors that could have biased the results.
Mechanical dating methods
A new micro-cycling machine has been designed for the measurement of single fibers
extracted from flax fabrics. These single fibers, about 1 mm long have been tabbed on a special self-
hand-made polyester mask with cyanoacrylate glue and subjected to multiple loading and unloading cycles.
a) Mechanical Multi-Parametric Dating Method (MMPDM)
A mean date of 372 AD.
b) Multiple Linear Regression (MLR)
260 AD with standard uncertainty of 137 years.
By means of vibrational spectroscopy, two alternative dating methods have been proposed based
on FT-IR and Raman analysis. These techniques exhibit different relationships between the
concentration of a molecular species and the measured parameter. Whereas infrared absorbance
follows the Lambert-Beer’s law, and therefore there exists a linear correlation between absorbance
and concentration, the use of Attenuated Total Reflection (ATR) can significantly change this relation
being both refraction and absorption indexes changing with wavelength and concentration.
a) FT-IR analysis
250 BC with 200 years standard uncertainty
b) Raman analysis
30 AD with 250 years standard uncertainty
FT-IR and Ramen dating: 140 BC with 156 years standard uncertainty
Mechanical and Opto-chemical
Shroud dated to 86 AD with 103 years standard uncertainty using mechanical and opto-chemical analysis.
Further work to improve these techniques:
To improve the reliability of the TS dating by the mechanical method, some more analytical
investigations can be done. These should consider also some weighting factors of the known
regression terms due to the different uncertainty of the flax samples dating. Furthermore, the
weighting should be extended also to the mechanical parameters determined for each flax sample. In
this way a total least squares procedure could be finally carried out.
An alternative way to improve the obtained results could be to apply an innovative robust procedure
so to avoid the definition of the uncertainty distribution that is instead required when a parametric
model is applied. Both kind of experiments are let for future works.
Shroud Wars: Panel Review (Part 3B)- Scientific Dating Evidence (with Giulio Fanti)
Questions and answers:
Presentation of talk:
https://realseekerministries.files.word … tation.pdf
Real Seekers page on dating of the shroud:
Joe Marino’s list of articles on dating of the shroud: