[AT] sundogs??

[rlgoss at insightbb.com]

Some of you guys are much better versed in that particular phenomenon than I am, George, but I assumed the bright spot that should be a shadow was a visual example of the fact that light bends when it passes by an object.  Astronomers are able to establish the location and existence of black holes on the basis of observing starlight bending around the invisible objects as it comes close.  I assumed the bright spot made by an aircraft is the same thing.  Light coming from the sun is broader than the shadow of any aircraft would be, so what ends up being observed on the ground (or clouds) as you fly by, is a shadowy penumbra region around a bright spot where the shadow should be.

This brings up thoughts about Schlieren systems.  Isn't the bright spot a subsonic Schlieren?  If so, what does the shadow look like to the pilot of an ultrasonic aircraft?  Humm.

Larry
 

----- Original Message -----
From: George Willer <gwill at gwill.net>
Date: Monday, February 11, 2008 19:40
Subject: Re: [AT] sundogs??
To: 'Antique tractor email discussion group' <at at lists.antique-tractor.com>

> The term is sometimes used to indicate the airplane's strange 
> shadow on the
> ground also.  It is very different from what one would expect.
> 
> George
> 
> > -----Original Message-----
> > From: at-bounces at lists.antique-tractor.com [mailto:at-
> > bounces at lists.antique-tractor.com] On Behalf Of Gene Dotson
> > Sent: Monday, February 11, 2008 7:29 PM
> > To: Antique tractor email discussion group
> > Subject: Re: [AT] sundogs??
> > 
> >     Sun dogs are an optical anomaly caused 
> by the sun beign refracted
> > through ice crystals in the upper atmosphere giving the 
> illusion there are
> > 1
> > or 2 extra suns in the sky. Usually will see one on each side 
> of the sun.
> > Caused by very cold ice crystals in the upper air.
> > 
> >                 Gene
> > 
> > 
> > 
> > ----- Original Message -----
> > From: "Paul Waugh" <pwaugh at embarqmail.com>
> > To: "Antique tractor email discussion group" 
> <at at lists.antique-
> > tractor.com>
> > Sent: Monday, February 11, 2008 7:03 PM
> > Subject: [AT] sundogs??
> > 
> > 
> > >I don't recognize this phrase .. 'sundogs'  can some one 
> tell what this
> > is
> > > ... yes Dave I know some one can
> > >
> > > Paul Waugh
> > >
> > >
> > > ----- Original Message -----
> > > From: "Ralph Goff" <alfg at sasktel.net>
> > > To: "Antique tractor email discussion group"
> > > <at at lists.antique-tractor.com>
> > > Sent: Monday, February 11, 2008 6:53 PM
> > > Subject: Re: [AT] TEST? NOW Ramble! (long)
> > >
> > >
> > > .
> > >> Sundogs and exteme wind chill warnings have been the trend 
> here since
> > >> Friday
> > >> when we dropped about 50 degrees in 24 hours.....
> > >>
> > >> Ralph in Sask.
> > >>
> > >> _______________________________________________
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