Sunrise

[Alex]

58 minutes ago, Squaredeal Sten said:

But estimating the size of Glorantha from celestial observations is still possible:   You have a flat world, and would need simultaneous observations of the sun as it goes though the sky:  Eatimate  east-west distances by measuring the two acute angles of the right triangles formed by the western point A, the sun, and the eastern points B and C.

Bear in mind what a huge deal it was in the RW to have even synchronised time, much less to be able to do simultaneous observations.  There were government projects to solve to longitude problem in the 18th century -- and think how annoyed people get about medieval, dark age, or even iron age tech or cultural tropes!  Ah yes, you say, but in Glorantha, we have magic to solve such minor problems.  To which I counter, no, we have magic to magic them infinitely worse!  The angles of a Sky World triangle add up to...  whatever Yelm says they do.  Personally, I don't think this method would work at all IMG, YGWV.

Does magical surveying in general help?  I'm happy to assume it does quite a bit.  Historical maps suck.  If you gave your players bronze-age accuracy maps as their best reference, you'd be beaten (very slowly) with them until you saw the error of your ways.  Gamers like a good map, and an authentically bad map is in many ways more work to produce!  Who wants to made a cartographic rod for their own back?

[Squaredeal Sten]

5 hours ago, Alex said:

 

.....  Historical maps suck.  If you gave your players bronze-age accuracy maps as their best reference, you'd be beaten (very slowly) with them until you saw the error of your ways.  Gamers like a good map, and an authentically bad map is in many ways more work to produce!  Who wants to made a cartographic rod for their own back?

I have no problem making an authentically bad map:  I did it a few sessions ago in my campaign, and charged a player about 20 lunars for it.    I drew it freehand, so the distances are not exact.  And I included some details and not others - which is the case with all maps, even modern topographic maps.  It's the difference between google maps map default view and their aerial photo view. Anyway, I drew it to the spec that i was given, in the context that the party was in, and interpreted it as a Lhankor Mhy initiate in the Jonstown Library might, putting in reasonable details given that said initiate did not know what the party intended let alone what would unfold in the campaign.  And indeed at that time even I did not know which way they would choose to go to reach their goal.

Edited October 25, 2021 by Squaredeal Sten
capitalization, grammar, clarity.

[Squaredeal Sten]

5 hours ago, Alex said:

Bear in mind what a huge deal it was in the RW to have even synchronised time, much less to be able to do simultaneous observations.  There were government projects to solve to longitude problem in the 18th century -- and think how annoyed people get about medieval, dark age, or even iron age tech or cultural tropes! 

Actually in my proposal I use the same technique those 18th century longitude projects used:  i rely on a unique celestial observation as the synchronizing method.  In this case not the transit of Venus across the sun, but instead Yelm's daily emergence from the underworld.  I do not assume that Yelm follows the same exact schedule from day to day.  Given a flat Glorantha, sunrise should be simultaneous all over the lozenge.  

[D]

when I setup the SkyDome, I used the distance between the dawn and dusk gates as the diameter, I think I found it in the Guide.

[D]

4 minutes ago, Squaredeal Sten said:

 I do not assume that Yelm follows the same exact schedule from day to day.  Given a flat Glorantha, sunrise should be simultaneous all over the lozenge.  

Yelms path is dawn gate, past Polestar then dusk gate, as the SkyDome tilts through the year, so does Yelms path, and it rises and falls vertically.

other than shadows cast by tall objects, I think dawn is simultaneous across glorantha

[Joerg]

14 hours ago, Squaredeal Sten said:

What makes you sure that Glorantha has a horizon?  If Glorantha is not round but flat, then you won't have an Earth type horizon otherwise known as the limit of observation caused by the curvature of the earth.  No mast heads of ships appearing first as they approach. 

Except that the curved light theory of MOB's has become quite canonical. The surface may be flat, but light bends down when it emerges from the eye on its way to the object seen, and if it hits the ground, that's what you see instead of the object in a greater distance.

Who would have made up such a theory of optics? Apparently some ancient Greeks had these vision rays emerging from the eyes. The curvature is pure Gloranthan bollocks, though.


Longitude doesn't happen in Glorantha. Time of day is the same everywhere under the Sky Dome, as far as can be measured. At noon, the sun is more or less directly overhead, depending on the tilt of the sunpath and the sky dome a little further south or north. The sun rises due east, in the same constellation seen from anywhere on the surface world before its rise, faintly under the red glow of Theya, the Jumper star which precedes the sunrise.

There is one stellar object that does change its position in the sky depending on where you watch it from - the Red Moon. That's because it is anchored on the Crater in Peloria.

 

The planets of the Sunpath provide a precision clock if you know how to read them. Mastakos provides a steady 8 hour beat. Lightfore gets tardy in nichts when the sun gets fast in the day, and vice versa, and by comparing that tardiness to the steady beat of Mastakos you know the date. The stars of the sky dome do an almost 24 hours rotation from sunset to sunset, the slight precession repeating on the exact same date - another way the night sky offers a time-keeping element. Depending on the tilt, the rim stars may dip below ground, or rise above it.
 

Precision measurement could use Stormgate, the Red Moon, the direction of Magasta's Pool using a magical compass, and the position of sunrise or sunset due east or west to do some triangulation that might allow an estimate of your coordinates on the surface.

 

There are no henges or passage tombs where the sun rises along that one specific angle once a year in Glorantha. It's every day, or not ever.

As a result, the south is not a preferred cardinal direction of sun cults (as it is in the northern hemisphere of our planet). The east probably is.

There could be wells or light shafts that allow the sun to fill the entire bottom two dates in a year when the tilt of the Sunpath brings the sun into the correct angle.

Edited October 25, 2021 by Joerg

[MOB]

On 10/23/2021 at 2:07 AM, D said:

I kind of agree and it makes my life easier, but in a world where the sun rises through a hole in the ground, surely it would be different?

Dawn and dusk on Glorantha look exactly the same as here on earth. How and why that happens is entirely different, and to me that's the point.

[Alex]

10 hours ago, Squaredeal Sten said:

Actually in my proposal I use the same technique those 18th century longitude projects used:  i rely on a unique celestial observation as the synchronizing method.  In this case not the transit of Venus across the sun, but instead Yelm's daily emergence from the underworld.

That was one of the methods applied, yes.  I dunno why that'd seem any less anachronistic than the split-minute precision steam-driven clockworkpunk one, though!  Indeed, presumably you'd need to combine the two, since you don't want to make your observations at Yelmrise (angle = zero, not a very useful surveying triangle), but at some precisely defined later time of day.  And you don't want to do that celestialogically, otherwise you have no independence of your assumptions and measurements at all.

 

10 hours ago, Squaredeal Sten said:

I do not assume that Yelm follows the same exact schedule from day to day.

Prudent, as canonically he does not!

 

9 hours ago, Squaredeal Sten said:

Given a flat Glorantha, sunrise should be simultaneous all over the lozenge.  

For me, that seems unlikely to be the case, for exactly the same reasons as with the horizon problem.  Your horizonless Glorantha will presumably vary.

[Alex]

3 hours ago, Joerg said:

The planets of the Sunpath provide a precision clock if you know how to read them. Mastakos provides a steady 8 hour beat.

I suppose depending on how many sigfigs precision you want to assume that period is, or whether there's absolutely no seasonal nor other variation in it...

 

3 hours ago, Joerg said:

Lightfore gets tardy in nichts when the sun gets fast in the day, and vice versa, and by comparing that tardiness to the steady beat of Mastakos you know the date.

Guid tae sei thi Scots leid beyin' spake oan thi forum! 😄

 

3 hours ago, Joerg said:

The stars of the sky dome do an almost 24 hours rotation from sunset to sunset, the slight precession repeating on the exact same date - another way the night sky offers a time-keeping element.

That one I'd take to the bank, and probably easier to work out if you have a general knowledge of the seasonal positions of constellations, or even if you just took note of their positions earlier that night.

 

3 hours ago, Joerg said:

Precision measurement could use Stormgate, the Red Moon, the direction of Magasta's Pool using a magical compass, and the position of sunrise or sunset due east or west to do some triangulation that might allow an estimate of your coordinates on the surface.

Yeah, I think that works, even without either the first or the last.  The compass thing might not be as refinable as the others just by getting ever-fancier celestialabes.  OTOH, if you go with the theory that Gloranthan engineering and trig is terrible (bronze-age level or go home!), but its magic is multiverse-beating, maybe one just needs to dump a ton of magic points into a sufficiently advanced compass to get arbitrarily precise directions.  Navigation Trace, Garzeen's infamously overpowered game-breaking rune magic!

So yeah, no longitude problem on Glorantha, it would seem.  The Creator Gods really made it easy for ocean sailors!  ... right up until they added ship-eating sea monsters, the Closing, and testy tribes of triolini, all armed with awls...

 

3 hours ago, Joerg said:

There are no henges or passage tombs where the sun rises along that one specific angle once a year in Glorantha. It's every day, or not ever.

As a result, the south is not a preferred cardinal direction of sun cults (as it is in the northern hemisphere of our planet). The east probably is.

There could be wells or light shafts that allow the sun to fill the entire bottom two dates in a year when the tilt of the Sunpath brings the sun into the correct angle.

Conceivably sun cults might favour south -- or north, or indeed Straight Up -- for the very reason that those do permit such monumental solar alignments.  Though east is pretty popular with solar-crazed RW religions too, obviously.

Maybe some of those Star Towers are notoriously Leaning?  Say by about 9 degrees north or so, and a little more than that to the south...