> Hello John and everybody on this list, > I don't want to extend this discussion endlessly >, but I am surprised to read that the value of >EOT depends on longitude. Perhaps I am totally >wrong, but for me EOT is absolute. It is linked >to the motion of Earth about the Sun and has >nothing to do with longitude. Taking again Jim >Cobb's formula, for any place on Earth : > >UT = Local Solar Time - EOT + 12 + Longitude(west >is positive). >The time when EOT = 0 is : >UT = Solar Time + 12 + Longitude ; or >UT = Local Sidereal Time - AD + 12 + Longitude >;and : >UT = Greenwich Sidereal Time - AD + 12 >Longitude of the place has gone away. >Am I wrong ? > >Best regards > >Jean-Paul Cornec > >. Jean-Paul
I was involved some weeks ago (relative to the location of the analemma) with this issue and now view the issue as follows. When the EOT is zero the geographical position of the sun and the mean sun (longitude only) are the same. This happens at a particular moment, ie. a certain time. The time is the same for everyone, subject to time zone changes, and the event certainly occurs associated with a definite longitude. This longitude changes somewhat from year to year due to the fact that the earth's rotation is not coupled exactly to its location in its orbit about the sun. Hope I am clear and correct for everyone here. Dan Wenger Daniel Lee Wenger Santa Cruz, CA [EMAIL PROTECTED] http://wengersundial.com http://wengersundial.com/wengerfamily
