Sky Stuff (long)

From: Stephen Martin <ilium_at_juno.com>
Date: Sun, 15 Feb 1998 16:05:54 EST


Alex Ferguson is a fellow Sky Lore fan, and I never realized it!
>Which reminds me, Steve, did you re-investigate the change-of-day-length
>thing? I intended to hack up a slightly more "realistic" approximation
>to this myself, but never got around to it.

Actually, yes -- I have been working on a number of topics related to the Sky Stuff. I now have all the raw data needed from Greg to determine the exact rising times of each of the Sunpath planets, I just haven't had time to sit down and do the math. Quite awhile back I figured out the exact timing of Theya and Rausa, too; though Shargash has some data known now, most of the rest of the Southpath is still being discussed -- I favor a longer period for it than does Greg at this time.

Although I don't want to go into great detail at this time, for a couple of reasons, here are a few points:

The length of day and night in Glorantha does in fact vary with the season. Although this is NOT because of the tilt of the Dome north and south, day length varies in exact proportion to the tilt. At this point, I favor a sinusoidal model (is that the right term?), rather than a fixed change one, to allow day length to change faster at the equinoxes* than at the solstices*.

Unless things change, on the Summer Solstice* day length is 14 hours 24 minutes (Theyalan reckoning), with a night length of 9 hours 36 minutes. As Nick Brooke originally determined, midsummer's day* is the day listed as Yelm's High Holy Day in Gods of Glorantha: Fireday, Harmony Week, Fire Season.

At midwinter*, night length is longer than day length at midsummer, because of the greater tilt of the Dome. But I am having trouble determing the exact length at this point -- my original calculations were off, and we have to redo them. This was only pointed out to me a week ago, I'm afraid. Regardless, the Winter Solstice* is Fireday, Illusion Week, Dark Season.

Currently, the model I am working from assumes that the two equinoxes* (Freezeday, Disorder Week, Sea Season and Clayday, Fertility Week, Earth Season) have day and night of equal length. The problems with day and night length above may force this to change, however.

The planet Shargash always rises in the exact same spot on the Eastern horizon, though the setting place in the West varies in a complicated cycle. This is the reason Shargash was recognized as a regular planet so early by the Dara Happans -- they saw him rise 100 times in the same place before they did so.

Theya is never visible when she is setting, only rising. Conversely, Rause is never visible rising, only setting. Currently, the model has Theya always visible for the same length of time at night, with Rausa's visibility being longer or shorter based on the season. Yes, this is a contradiction from Elder Secrets.

If people have specific questions they would like to ask me, please let me know, and I will answer them as I can, and as I am allowed to. Hopefully, there will be a complete and working model available for distribution before too long, that is the goal of my current research.

Jane Williams demands, with good reason:
> Do we have a Zodiac to play with?

Alex replies:
>No actual zodiac, since the sun and the stars move along different
>nightly paths (d'oh!). I think the most likely analogues are: the
>constellations along the horizon; and the constellations around Polaris.
>Gloranthan star-fans could then say a given body is "in" a constellation
>on a given day or night if it (variously) rises in it, passes through it
>in the Upper Sky, or sets in it. I think I considered the first scheme
>for Kralorela, the second for Dara Happa (or maybe vice versa: argh!)

In fact, a probably near-universal equivalent would be the constellation in which Lightfore rises each night -- this will be a uiversally visible phenomena, as Lightfore is the brightest of all the planets, and is probably brighter than all but one or two stars. Given the early wanderings of the proto-Buseri across most or all of Genertela based on Greg's current view, it is likely that the association of these constellations would be fairly consistent (though affected by the local culture and religion).

This is not to say that other constellation systems might not exist, but it seems likely to me that 90% of Genertelans would stick with Lightfore's rising constellation. Depending on how you count them (and whether individual stars, like Oasis, count) (and, whether the constellation must be near the horizon, or is simply the first one Lightfore reaches, such as in the Desert), you can get anywhere from 12 to 20 such constellations. I have not investigated further at this point.

I also favor a model for the West where they view each of the planets as an astrology-style primal force, which rules the lives of mortals. I don't think such a scheme would be prevalent anywhere but in the West, though I imagine that the Holy Country would be full of astrologers analyzing your personality based upon where the Love Planet, War Planet, King Planet, etc. were at the moment of your birth. But this is a nascent idea, based on a single conversation with Greg.

Another semi-interesting tidbit -- the Twin Stars were originally Yellow-white in color, as described in Elder Secrets. They had no visible cyclic nature until the coming of the Red Goddess. At the moment they were illuminated**, they began to exhibit a cyclic nature -- on Dark and Dying Moons they are still yellow-white, gradually changing to bright red on the night of the Full Moon, then returning to yellow-white. And because the Full Moon is on different days in different parts of Glorantha, a viewer in Fronela might see them as red on a day that a Kralorelan sees them as Yellow-white. That is my current belief, anyways.

"THE TWIN STAR SISTERS were said to be the daughters of the Red Moon and an otherwise unknown 'man inside the invisible shirt.'" Who is, of course, Nysalor -- this refers to their illumination, so I am told.

>The presumption seems to be be that there are no "latitude effects" in
>Glorantha, but one never knows... This is one of the things I wanted to
>pin Greg on, but haven't managed to. There are two separate issues,
>here, in fact: latitude effects per se, and those caused by parallax.
>By actual latitude effects I mean those caused by living on a curved
>world (which Glorantha isn't), or an _apparently_ curved world (which it
>is -- see Wonky Light thread _passim_, ignoring the more plaintive cries
>of pain it caused).

An area of exploration for you -- even a flat world will have parallex effects if the stars are close enough. The current working model has the Sky Dome approximately 20,000 km in radius (though admittedly one is far, far into the God Plane at this point, it is used to determine certain potential physical correspondences -- I gotta start somewhere). Although this might as well be light-years as far as most Gloranthans are concerned, it is moe than close enough to get a parallex difference given two viewers in Yuthuppa and in Pamaltela. The exact differences haven't been worked out yet, of course, but they do seem to be there.

An example of why this might be important is that it affects the constellation in which a given planet (such as Lightfore) is seen to be in at a certain time. Differences near the horizon would be slight, but differences at the "top" of the sky could be significant, depending on how ":far" the planetary paths are from the Sky Dome. And certainly angles between planets would be affected.

>There are other sorts of "precession" which probably could be nic^H^H^H
>adapted to Glorantha, though. Degree of axial tilt, orbital transit,
>eccentricity of orbit, and likely several others I'm forgetting all vary
>on earth, with effects that could be "simulated", even in a world that's
>Copernicus' and Galileo's worst nightmare...

The degree of axial tilt appears to not change over time, and I don't know what orbital transit is, nor do I see how eccentricity of orbit could affect things here. Elder Secrets says that Pole Star has a yearly wobble, which implies to me that he does not just move due north and south, and I am investigating just how far to the east or west we can move him -- one very important myth actually hinges quite closely on this, and it could certainly follow a pattern that takes longer than a year to play out (I favor ten years for Dara Happan reasons, but it could be longer).

>More serious "lacks" in the Sky are non-integral periods for different
>heavenly objects (and worse, ones that don't have pretty trivial lcm's,
>for the most part),

Yes, this is a serious lack, and one which we unfotunately are stuck with. But this makes sense when you consider that the Gloranthans _know_ the sky was perfect once, created by the Gods to be perfect, which is not necessarily the case on earth -- did any ancient peoples wish that the planets were more regular, or wonder how they got screwed up?

>varying rising and setting points, retrograde motion, that type of thing

Well, with the Southpath we do get varying rising and setting points, at least for three of the planets (well, for 2 1/2 of them anyways). And the Southpath is the source of most planetary variations in Glorantha.

We do have some planets who have changed their motion in the past (Wagon and the Boat Planet, which had a very slightly irregular path). As far as I can tell, we only get retrograde motion in Lost Rocks, and I do favor finding some sort of mathematical model (however complicated) to explain its motion.

Additionally, given that the Blue Moon _is_ a moon, I would expect that the apparently variable 2-7 day period of the Blue Moon actual follows a somewhat complicated cycle, and this could also be of importance to star seers -- "if the Blue Streak is falling at hour x of day y, then the importance of the angle between Shargash and Lokarnos at that time is thus, whereas if the Blue Moon is rising along the Dome it is thus, and if the Blue Moon is traveling through the Underworld it means thus." Note that the current model has the Blue Moon (invisible, of course) always rising in the east at the exact moment that a certain star of the constellation Lorian is due east -- Annilla rising upon the Blue Dragon. Thus, the hour of the rising of the Blue Moon varies, as does the houy the Blue Streak occurs.

Another possible source of importance to Gloranthan star seers is the length of time before Dawn and after Dusk in which light is visible. A fragment of Greg's Harmast's Saga has a student of star lore in Dorastor tasked with detailing the length of the gloaming (time light is visible after sunset), and I think that this time should vary with the season. Given the Dara Happan fixation on the light of the Sun, the amount of light in the sky and the positions of various planets could be important as well. But that is probably too esoteric for most people in Glorantha to care about.

>One can only imagine than anyone trying that sort of stunt in Glorantha
>would either be swiftly executed when one of their more blatantly
>observable predictions bombed, or would be landed with the sort of rep
>for stiff-necked intransigence and mental inflexibility normally enjoyed
>by dronars hacking away at glaciers with their hoes -- or with Dara
>Happans, most days of the week, come to that...

It is worth pointing out that I believe some of the more conservative Buseri perform all of their calculations as if the lengths of day and night were equal every day (an idea which I believe also originated with Nick); they might ignore certain other variations in the sky as well, to

>Given what we know of the Buserian model, it seems more likely that said
>latter variations (angular differences between Sunpath planets and the
Sun) >are reckoned according to position in the _Sky_, rather than relative to the
>path of the sun. Introducing a slight wiggle into the course of the
>Sunpath planets (other than Yelm and Lightfore, of course) would give
>some extra complexity without really breaking anything else, however.

Given that Pole Star may have a slight wobble, it is possible to have Lightfore and the Sun always follow a "perfect" Sunpath (through where Pole Star is supposed to be), while the Sunpath planets travel a path through Pole Star, wherever he is. After all, I think most cultures will account Lightfore and the Sun as greater than Pole Star, but could easily see the others as being subservient to the head Star Captain, since they are but "wandering stars" after all. Since each planet is on its own Crystal Sphere if you follow a Greek model of the Heavens (which I do), they do not have to follow the exact same path.

IN CONCLUSION
As I am working on the Sky Stuff fairly regularly (with someone competent doing the math, I assure you), and talk to Greg about it when needed, I am open to any questions, ideas, suggestions, or corrections anyone might note, though I ask that such be sent to me directly to ensure a reply. Greg's and my intent is to making a working, accurate, interesting model that is useable both to determine historical events and to give local color and detail to campaign events. Anything which will serve either goal would be appreciated.

Stephen Martin
ilium_at_juno.com

- -----------------------------------------------
The Book of Drastic Resolutions
drastic_at_juno.com

You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866]

End of The Glorantha Digest V5 #423


Powered by hypermail