Arthur Carlson wrote: >is there any > chance of getting around the 2 minute limit on sundial accuracy due to the > sun's angular diameter?
This part of your message struck me as something new. We've had many discussions about the limits of precision attainable, but this is the first time I have heard that it is two minutes. I can read the center of the cable gnomon's shadow on my Flandrau sundial to within 20 seconds. John John L. Carmichael Jr. Sundial Sculptures 925 E. Foothills Dr. Tucson Arizona 85718 USA Tel: 520-696-1709 Email: [EMAIL PROTECTED] Website: <http://www.sundialsculptures.com> ----- Original Message ----- From: "Arthur Carlson" <[EMAIL PROTECTED]> To: "Sundial Mailing List" <sundial@rrz.uni-koeln.de> Sent: Tuesday, January 08, 2002 2:19 AM Subject: AW: Polar ceiling sundial > Since a caustic is a very different animal from an image, is there any > chance of getting around the 2 minute limit on sundial accuracy due to the > sun's angular diameter? Does the caustic of an extended object form a line, > or is it also smeared out? (I suspect there's no free lunch here, but I > thought I could ask.) > > --Art > > -----Ursprungliche Nachricht----- > Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Auftrag von Tim Yu > Gesendet: Tuesday, January 08, 2002 3:22 AM > An: Sundial List > Cc: Tim Yu > Betreff: RE: Polar ceiling sundial > > > [David] > > What is a caustic curve? > > See the website: > > http://www.cacr.caltech.edu/~roy/Caustic/ > > A simple Java applet demonstrates how a caustic curve is formed by > parallel light rays bouncing off a cylindrical, reflective surface. > > > Tim > >
