[Swordmaker]

But then, neither do they go to physicists, generally. A physicist might well be able to tell you that the wood or canvas is however many centuries old, and the paint is composed of X

Actually, they do. The physicist and the Chemists can tell a lot about the painting's provenance.

Huh. I'm sure Harry Houdini might have some things to say about that.

Are you channeling now, Orion? Erich Weiss (aka Harry Houdini) has been dead since Halloween, 1926. I doubt he can say much of anything. If you are referring to his exposure of frauds, he only exposed the "performance frauds" of the mystics and seers who claimed they could speak with the dead or allow others to do so.

Amazing what traces the passage of centuries will erase.

You have great faith. Please show me any other work of art in which ALL pigments, stains, or other image producing media have completely disappeared, leaaving no detectable trace, over any length of time.

[orionblamblam]

> f you are referring to his exposure of
frauds, he only exposed the "performance frauds"

Well, except for all those pesky "ghost photos" and "fairy photos..."

> Please show me any other work of art in which ALL pigments, stains,
or other image producing media have completely disappeared, leaaving no detectable trace,
over any length of time.

Gosh, you're right. The shroud ahs faded so far it's invisible.