So no diffraction gratings? Cause if only 3 beams we cannot submit pictures of a multiline Argon with all its lines? If we can use a diffraction grating, then a lot of Brucemir's would be good to go since it looks like he uses diffraction gratings with 2 or 3 lasers to achieve the myriad of beams.
Bugs. Gotta be. We have like four species of night flying bug eating birds around here and they are often WAY up there. ( day time Swallows and Purple Martins too ) Evidently some species of bugs do their thing far up in the air. Dust would not be recognizable in a laser beam at hundred or two hundred ft in the air. Plus it would not make those big 'splashes'. JMO :tinfoil:
Dang! One of these days I will spend awholelotamoney to get a decent yellow laser. :eg: