I remember talking to an older man in S. Korea who was a former slave in Japan when one of the atomic bombs was dropped. He had his back towards ground zero during the brilliant flash of light and heat. The pattern of a denim shirt he had on was “tatooed” into his back. He raised his shirt up and showed me.
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I put little if any stock in the Turin cloth being the actual shroud of Jesus.
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However, as a "gedanken" (thought) experiment, consider this:
1) Bodies in Jesus' time were washed and coated ("annointed") with perfumed oils.
2) A cloth is placed in proximity to the body, covering it.
3) The body, itself, totally disappears in a flash of energy.
4) The oils (or their residue) vaporize and travel at speed toward the cloth surface.
5) Following the inverse square law, cloth closest to the body gets the densest (darkest) coating of the condensing material; areas farther away (opposite eye sockets, for example) get proportionally lighter coatings.
Voila! -- a negative image -- only on the surface of the cloth fibers...
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That's an analogue of "Dye Sublimation Printing"...