Re: Gloranthan Eclipses

From: Alex Ferguson <>
Date: Sat, 21 Apr 2001 01:26:25 +0100 (BST)

Mike Dawson:
> It seems to me that there must be a band of geography in the northern
> part of the Pent, the Lunar Empire and Rathorela where there is a solar
> eclipse every day. The moon hangs there all the time, and the sun is
> higher and further south than it is.

The complexification here is the "height" of the moon. Greg's not been pinned down 100% on this (though since he posts to the Digest more often than I do these days, you should all feel free to try...), but the gist of it seems to be that it's at "height weird", and appears at a position in the sky determined by mythic and magical factors, rather than by mere materialist trigonometry. And just to rub salt on the wound, the apparent height depends if you're inside the Glowline or not -- inside, it looks like an actual celestial object, essentially; outside, not quite sure yet).

> Of course, determining where this Eclipse band is would require
> extensive celestial head scratching to determine the angle of the
> Red Moon relative to the Sunpath.

Yer no' kiddin'... As I say, I don't have bomb-proof info on this, but doing a quick check of my "working model" assumptions, it _appears_ that at any given point within the Glowline, you'll get a total eclipse once per year. They'll be much briefer than terrestrial ones, however, because the RM is stationary. (This is all assuming the RM and Yelm have disks of the same apparent size.) How many partial ones you might get makes my head hurt a bit too much right now.

> I suppose the Blue Moon also eclipses the sun once a week, but I'm not
> sure what effect an invisible eclipse would have. Sounds weirdly
> mystical to me. The path of that shadow would also be directly over
> Magasta's Pool.

It's been my assumption that the Blue Moon is much "smaller" than the sun, as are the other planets and moons. The BM is also invisible/ behind the sky dome, as has been alluded to, but any planet's "conjunction" with Yelm would be effectively invisible anyway, due to the differences in size and brightness, unless some Weird Magical Effect(TM) comes into play. After the Red Moon, the largest and brightest object in the sky is Shargash. My understanding is that it's not quite big enough to eclipse the sun, and not on the correct path to do so anyway. At least, "not normally"...

> Annilla doesn't eclipse the sun (as viewed from the ground) while
> traversing the Dome--She eclipses it while she falls through the
> center of the world, manifesting her "Blue Streak".

That wouldn't have the appearance of an "eclipse" under circumstances where Yelm's in the sky world, and the BM is in the Inner World: that would be more akin to "the Goodyear blimp passes in front of the sun".

> In fact, if the eclipse happened exactly at noon on a spring or
> summer equinox, AND we can assume that Annilla rises as high on the
> Sky Dome as Yelm (I'm not at all sure we can assume that) THEN at that
> exact moment Annilla and Yelm would be in the same place.

That would be the one circumstance in which an "eclipse", or rather a conjunction would be possible, at the very instant the Blue Moon starts to "fall out of" the sky world, and might be "in front of" Yelm, while they're both at "mythic" distances, in fact. I can't imagine it would be normally perceptible, but it _does_ sounds a little weird and spooky, all right. It would in all likelihood be _very_ rare, due to the 'random' nature of the Blue Moon's motion (i.e. there's a D. Phil or twelve at Yuthuppa U. in it for anyone ever working this out).

These celestial matters are topics that about half a dozen Gloranfans find _utterly fascinating_, while evidently sending several thousand other pretty much instantly to sleep. Please bear with us, all ye of the latter camp.


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