reply to post by MickC
But, since there is no such thing as a "black laser beam" then you can immediately toss that concept out the _ (It would also be informative
to study and research lasers in general. The "beam" of a laser is generally NOT visible, unless it is being projected through some medium...some
sort of particulates suspended in the air, for example, to make it visible).
And, in any event....airplanes do NOT "follow" lines in the sky. A bit of aviation and aeronautical knowledge would come in handy, too. (Sadly,
that is completely lacking amongst the myriad of "chem"-trail websites online....they are rife with absolute nonsense that seems "plausible", I
suppose, to the layperson. That's how "snake-oil" salesmen ply their wares, too.... of course).
Your "black line" could have been nothing else but
a shadow....your description makes that clear. Where the confusion arises is a
matter of perspective. The shadow did not represent the entire length of the contrail....as you pointed out, the portion of the trail first formed,
and well behind the airplane was spreading, as contrails will do. You were seeing the "newer", "sharper" part just being made, as it continued to
project a shadow.....the shadow was "following" the airplane, not the other way 'round....
Perspective of being on the ground, viewing at just the right angle, gave an illusion of a longer shadow....what was the time of day, and Sun angle?
Consider that....it's important, too.
Remember how shadows work....they can be MUCH longer than the object that is casting it (Earth-bound examples):
Those, cast against the ground, and seen from about the same level...compared to being cast against the expanse of the SKY!
And, of course, you know of the other illusion, with contrails? Seen at the right angle, they appear to be vertical..."As if" they are rising from
the Earth's surface,upward. When, in fact, they are not.