Not A Poet
Stephen, I thought that was what I said. I intended to anyway.
It has been a very long time since college physics and optics was not my best anyway but I don't think a laser light would be bent say by passing through a prism like ordinary light. As I recall, light is ben by a prism because it is made up of multiple wavelengths. The longer ones (red) being slowed more than the shorter ones (blue) by the change of optical density passing into then out of the prism. Gee, I think that's right. Since a laser must be a single wavelength, I don't see how it could bend.
Ok, I guess that is really a new subject, so, no more on that now.
But yes, the shadow is not a presence. It is the absence of light (or reduction of light) caused by the object between the source and the target. That, to me, invalidates proposition #2.
Hey, thanks again for making me think and try to remember old, old stuff.