i didn't notice that the lines were slightly off from vertical before. the times i have seen this, the angle was much more visible because the effective horizon is higher here with nearby mountains in the west.
Herb... ----- Original Message ----- From: "Anthony Farr" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, March 02, 2004 6:34 AM Subject: Re: March PUG > For most of the day the sky is between the sun and the viewer, but at > twilight the sky is above the sun relative to the viewer's position. As > twilight progresses the directly sunlit sky retreats upwards, but the edge > (or more correctly the bottom surface) of the sunlit zone is visible because > of dust and water vapour in the air. .Sometimes a distant cloud, perhaps > even over the horizon, casts a shadow into the sky which creates a 'step' or > 'notch' in that surface, and that is the change of brightness that you > photographed.
