Re: interesting pic for a classroom exercise?

["Kilmer, Skip" <kilmers@GREENHILL.ORG>]

By a lucky coincidence, last week, just after I bought a solar filter for my
little Meade scope, I saw the same thing. No more than a couple of seconds
after I found the sun, a 737 flew in front of it. One of thowe WOW
experiences. My question for the group, however, is why the exhaust trails
are so opaque. They were in what I saw, just as in this photo. I looked at
the plane a few seconds later, and the it was not leaving visible contrails.
Refraction phenomenon, maybe?
Skip

> -----Original Message-----
> From: Stefan Jeglinski [SMTP:jeglin@4PI.COM]
> Sent: Friday, January 26, 2001 2:30 PM
> To:   PHYS-L@lists.nau.edu
> Subject:      interesting pic for a classroom exercise?
>
> <http://perso.club-internet.fr/legault/s010113.jpg>
>
> Q: how far away is the plane from the camera?
>
> My zeroth-order back of the envelope, unchecked, rough estimate, is
> 30 mi. Seems reasonable, but this depends linearly on the assumed
> length of the plane in my approximation. People familiar with
> airliners can probably recognize the plane immediately and know its
> length...
>
>
> Stefan Jeglinski