Chemtrails/contrails "black beam" question?

This isn't about chemtrails/contrails or whatever they are. This is about the black shadow or "black beam" (as some folk call them) that come with the trails. Question - Why is the shadow always dead straight when the contrail has been blown into a squiggly line?

I've never heard about a black beam before. Any pictures available?

Are you talking about anti-crepuscular rays like this one?

Dramatic, but not mysterious.

Here's one from youtube but there are loads of pics onlne. I've seen a few myself. I know it's just a shadow but I've always thought it kind of wierd that the line seems to stay straight when the trails disperse.

Originally posted by Tom Bedlam
Are you talking about anti-crepuscular rays like this one?

Dramatic, but not mysterious.

Well, they were mysterious to me till I read your post. Thanks for the info. I'm going to look into this right now. Cheers.

[edit on 24-10-2007 by wigit]

There's some pretty good photos of anti-crepuscular rays on the net. The one of the Atlantis launch is probably the most striking I've seen, though.

It's a shame that Greenler wants so much for his tape on the subject, I hear he does a great job explaining it.

Looks like exhaust to me after the ice crystals fade away. Great dancing music by the way.

mikell

I love sky pictures but the ray ones are fabulous. Thanks. You learn something new every day, (well, about once a year in my case. ) It was about a year ago I found out what diamond dust was. Nature never ceases to amaze me.

I saw a "black beam" in the sky in San Diego a couple weeks ago when the trails were heavy.
I was by the beach in La Jolla near sunset (which occurs in the West). I looked up and saw a long black beam pretty high in the sky and thought it seemed odd. Less than a minute later, a plane comes along following the beam leaving it's (whichever prefix you prefer) trail in the beams path. I see a lot of people claiming this "black beam" is a shadow, but the plane was heading East to West, toward the sun, so the shadow would be behind the plane, right?
Looking forward to finding out the truth on this and many other theories.