Yeah, I had been thinking of a globe sundial for awhile also. One other thing you could do is make many gnomons around the globe in a circle at every 15 degrees (for each hour), and mark a line directly under each gnomon on the globe.
Then, you can tell at which place it is exactly noon, and once you've done that, you can simply count the gnomons around to another area to add or subtract hours and get a very precise time reading. I'm new at the sundial thing, but I think this would work. I have ideas for using circles of gnomons which each represent an hour, so that whichever one is casting a shadow to the center is the current hour. By the way, with everyone talking about using the Schmoyer dial on the Southern Hemisphere, I got to thinking about using sundials in different latitudes than they were meant for. I came up with this: it should be possible to use a sundial in any latitude by angling the entire thing (dial plate and all) so that the gnomon aims directly North (or South). Of course, this wouldn't work with Northern-hemisphere sundials in the S. hemisphere or vice-versa, since the dial plate would end up upside-down (which, when read from above, gives counter-clockwise numbers!) I think one idea for a sundial that would fix this is this: a gnomon that is horizontal to the dial plate. The lines on the dial plate would be parallel with each other and the gnomon. Lay it flat if you are directly on the equator, and angled up towards the North or South on the N and S hemispheres, respectively. --And on the Sundials on the Internet web page, I found that this type of dial is a "polar dial". The dial plate could also be curved in a circle, so then it would be more of an armillary sphere. Whoever said more explanations of the math involved in sundials were needed, was correct. I haven't had any math classes for a couple years, and the talk of all these equations is making me want to get back into it! Ryan Weh Sundials are truly magic!! Jeff Adkins wrote: > Ryan Weh wrote: > > > > > (Would it be called "equitorial"?--the dial plate is perpendicular to the > > gnomon) to set in my office window right now. > > > > Equatorial. Yes, that is a characteristic. The gnomon will point north and > should be tilted upward from horizonal at an angle equal to your latitude, > which makes the gnomon parallel to the earth's axis and the dial face parallel > to the plane of the equator. > > -=-- > ...and it occurs to me that if you were to take a miniature globe, such as the > kind often found on pencil sharpeners or key chains, and stick the south pole > of it on the end of your gnomon, then rotate the globe so that your location > on > the globe is on top (pointing toward the zenith) then natural sunlight on the > sundial would make the sunlit face of the miniature globe exactly mimic the > sunlit face of the earth. > > This would be much like the globe found in many model celestial spheres > suspended within a transparent globe of stars. > > You could then tell what time it was in other locations at a glance. > > It would even compensate for latitude differences and seasonal differences > automatically. > > Hmmm.... > > ...there's a sundial design in there somewhere. > > Jeff Adkins
