>>A bit off the refraction topic but Chuck O'Connell expressed interest in >>dials that use polarisation. There was an interesting article recently in >>one of the BSS Bulletins about using Sellotape as a polarising medium to >>make a dial that would indicate hours even when it's cloudy - it uses the >>fact that the background light from the sky is polarised. > > The article was in the BSS Bulletin 98.1 February 98 pages 3-9. The >'dial' > is based on Charles Wheatstone's use last century of the polarisation of > skylight to determine the azimuth of the sun. > > Les Cowley
There also was an article in Sky & Telescope magazine a while back which showed a sundial using polarized light from the sky. I can't lay my hands on the issue, but I believe it was about 18 months ago. Mac Oglesby
