I had asked Ludwik "What kind of instrument did you use to make this scratch?"
His reply came after our deadline for NET25. I enclose it if it helps.
"Steve,
Any mechanical scratch is ALWAYS surrounded by tracks-looking pits.
That is why one of the rules of counting, established by oriani, is to
ignore tracks which form straight line segments. Tracks that are very
close to the edges are also not counted; they are probably produced
during cutting. The picture you have was a very shallow scratch. I do
not remember how it was produced; most likely not deliberately."
The thing that I didn't completely follow in his logic was, if he didn't
know for sure how the "scratch" was caused, how was he sure it was a scratch?
And the fact that nature caused a repeating pattern, with nearly a perfect
similarity in each of the groups and sub-features and their relationship to
each other, in a slightly crescent, shape seemed inexplicable to me.
S
