Great examples!

Thrown together from cardboard and dowels and a PAR yanked from my living room. I'll probably redo this demo with more controlled objects and terrain and an actual sun angle of 9°.

You can even see highlights on the ribbed edges at the top of the battery on the shadow side created by the reflected light from the table.

Sure, you and I agree that's what they are. But try to tell that to a hoax believer, who will just maintain it's scatter from the atmosphere.

Your examples taken with the par lamp also show the other limitation of studio light...falloff.

True. I have touched on this in various posts elsewhere, but I haven't gotten around to discussing it in detail. Of course a real studio lighting designer wouldn't use a PAR or any kind of flood to create the shadows on a set. But of course a focused spot (e.g., ellipsoidal) has other unpleasant properties. And there's still falloff.

I have some proof photos of various umbra/penumbra effects, but so far no page in which to incorporate them.