On Thu, 19 Sep 2002, [ISO-8859-1] Anselmo P?rez Serrada wrote: > Dave Bell wrote: > > >part way, maybe 90 degrees. Ah-HAH! It's the old effect of blue sky light > >being fairly highly polarized, especially in the morning and evening. This > >interacts with the polarized filter overlaying the LCD screen, to give a > >directional sensitivity that doesn't happen under artificial lighting! > > > >This only works in the shade (contrary to the anti-sundial ideas), with > >clear sky. Hold the cell phone or PDA horizontally in front of you, while > >you rotate through 360 degrees. You should see two distinct peaks and two > >valleys of shade on the screen. The lighter condition corrsponded - on my > >phone - to North and South. > > > > > This sounds quite well but does anybody know if it is accurate within, > say, +/- 15 deg and if it can > be done with any LCD screen (big enough and in the same shade > conditions, of course)? > > Best regards, > > Anselmo
Well, it's probably good to within 15 degrees, BUT, I realized last night that it isn't related to compass direction, but rather to the Sun's direction! It's another sundial... No real help. Dave 37.28N 121.97W -
