Friday, May 12, 2006
Shadows during the annular eclipse
Günther Können took these pictures in Madrid during the annular eclipse of 3rd Oct 2005. They are solar images projected onto three mutually perpendicular surfaces: one horizontal and two vertical. During the annular phase (right hand image) the solar images were ellipses, with their long axes oriented in different directions on the two walls and the steps and ground. This was not unexpected. However, in the picture showing the pre-annular phase, one notices that the sun crescents on the ground and steps comprised the more pointed part of the ellipse, whereas on the walls they are the more rounded part of the ellipse. The key is in the third picture, where the shadow of the roof overhang kinks from one projecting plane to the other. In hindsight, all of this is understandable, but I have never seen a comment on this 'solar image puzzle'.