What Kind Of A Shadow Is This?

[nomadguy]

Posted by Dennis Leahy (here)

Posted by RMorgan (here)

Posted by Dennis Leahy (here)
... I don't believe a shadow can be cast onto blue sky...

It´s not a matter of belief, Dennis. It simply can...Well, not in the sky itself, because the very word sky is relative and subjective, but in the atmosphere, which has volume and a billion kinds of suspended particles.

Clouds, trails or anything else between the sun and your point of view will cast shadows.

...will cast shadows ONTO [________________] <-- something of substance, not blue sky

Hi Raf,

As an amateur photographer, I have photographed the sky thousands of times, and have looked at many thousands more in magazines such as "Outdoor Photographer." As someone who has spent a lot of time outdoors, I can't even guess how many times I have seen blue skies. I have seen clouds cast shadows on clouds and on the ground. I have never seen a shadow "in the clear blue sky."

You need a "screen", an object, or something of substance to cast a shadow upon.

There are two pilots in my extended family, so I'll add that I have never seen a shadow cast from a contrail or aerobatic smoke, cast onto the blue sky either.

I have also spent hundreds of hours in 3D animation software, learning about all of the types of lighting and how to deliberately cast shadows (for realism.)

Again, if there is enough crap/pollutants in the sky to turn it from "blue" to "hazy", then I think it is feasible. However... in addition to the hazy non-blue sky conditions, the sun would need to be very low in the sky, behind the plane of the observer, to cast any visible shadow onto anything of substance in the sky (such as a cloud.)

I have a bad habit of sounding dogmatic, and over the years I have made my words more gentle and less dogmatic by using phrases such as "it seems..." and "I believe..." but in this case, I'll go ahead and be dogmatic and state that it is impossible to cast a shadow onto a normal blue sky. ("Blue sky" indicating that there is nothing of substance upon which a shadow could be cast - and I use the word "normal" to indicate the sky as it was for the first 40 years of my life, when no contrail or cloud or bird or jet could ever cast a shadow onto the "empty" blue sky (which even included some industrial pollutants.)

Dennis

I happen to agree with you on this point Dennis... However if this 'visible vapor trail' regardless of it's contents, were a lot higher up in the atmosphere couldn't it then have this effect? I ask this to expand the inquiry I also agree that you need a fair amount of particle in the air to create a 'volumetric shadow'. Like you might see in water. Far more than was presented. I too am an outdoor photographer and I have never seen this phenomena without these 'persistent contrails', chemtrails whatever they really are. Occasionally after a thunderstorm you may see something similar, where a large thick cloud with enough dust and water vapor in the sky generate a long volumetric shadow as the sun nears the horizon. But from a single thin contrail in mid day... How can that be explained?

[Ol' Roy]

Hey Fred,

Brilliant observation. We vacation in Pigeon Forge every year about this time.

We see some of the most unusual phenomenom in the skies. Maybe has to to do with the humidity.Especially looking at I 40 E and I 75 N all toward the mountains.

Hope you are enjoying Tennessee! I like it down there myself!

Oak Ridge is just outside Knoxville! Still highly classified! Just a thought!

Just up the road, your ole Kentucky buddy, Roy

[noprophet]

Remembered this thread from awhile back and just wanted to note that I saw one of these in person the other day while walking home from work. I was going to take a picture when i got home but could no longer see it. I don't know if it "dissipated" or it couldn't be seen from a different angle but it was on an empty blue sky with a "contrail" across it.