Dear Rudolph, You are quite right to doubt my explanation:
> If rays from the sun are deflected > downward by the mountain's knife edge, > wouldn't their light appear to come > from higher up in the sky, rather than > from lower down? I was unconvinced myself! I have now consulted various experts (physicists and photographers) and we currently think the answer lies in Roger's use of his camera... There is a huge change in brightness between the centre of the solar disc and even half a degree away. This is a big challenge for a camera and what we are seeing is local over-exposure. On the image sensor at the back of the camera, there is spill-over of light onto neighbouring pixels. If Roger had used a sufficiently dark filter, the sun would not appear to spill over the edge of the mountain. One of my experts noted that he had witnessed an annular eclipse of the sun. At peak eclipse, if viewed for a brief instant with the naked eye, the largely-obscured sun looked very much as it normally does. The small annular ring of light spilt over the entire surface of the moon. When viewed with eclipse glasses, the annular ring looked convincingly like a ring of light. In short, the bite taken out of Mount Baker has nothing to do with diffraction, refraction or the atmosphere (or lack of it) on the mountain. Frank King Cambridge, U.K. --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
