> If the axis of rotation was perpendicular to the sun, we'd still
> have longer days on the equator compared to closer to the poles,
> because (due to curvature of the earth) the sun would be visible
> for less time the closer you get to the poles.
Not true. It would be a perpetual equinox, except at the poles which would have 24 hours of light. Due to curvature, the higher latitudes would have longer periods of twilight, too.
Me:
>> The fact that each noon has the sun almost vertically above has >> always been one of the stranger facts of Glorantha to me (more so >> than any horizon theories).
> It occurs to me, that isn't quite correct.
> If the sun travels above the nominal equator during the course of
> the day, then at noon, the sun would be (roughly) above Magasta's
> whirlpool, yes?
Yes. However, the Gloranthan sky has no meaningful parallax towards the ground. That means if a stellar body is up 38 degrees north viewed from Pamaltela, it won't be any higher viewed from Genertela.
> On the nominal equator, the sun would move in an arc through
> the middle of the sky, straight up over your head. 'north' or
> 'south' of the equator, you'd see the sun travel in an arc.
If the sun had a measurable distance from the ground, yes. Since it doesn't...
> In the north, it would start in the southeast, peak, and set in the
> southwest. In the south, the reverse.
That doesn't seem to be the case. Both the Gates of Dawn and Dusk are so far outside of the "Circle of Time" that they appear directly east and west from anywhere within the "Circle of Time".
> Hmm. Sundial type clocks would theoretically require calibration
> both north/south and east/west, making them much more complex than
> earthly ones, which just require calibration for distance
> north/south of the equator.
Sundials don't really work on Glorantha. Yelm, and in the nights Lightfore, move at varying angular speed across the sky. You could create a sundial if you took a flexible piece of graded metal whose curvature you could tune to the angular movement of Yelm. You can ignore vertical deviation of the sunpath (or include that in the curvature tuning). Basically, you get a horizontal needle and a curved east-west-strip of grades that allow dawn to cast a shadow on the western time mark and dusk a shadow on the eastern time mark of the dial. By knowing the date, you can calibrate at dawn.
> Sun dials show subjective time, rather than mechanical time. If you
> divide the day into 12 hours, by dividing the time from sunup to
> sundown into 12 hours, your hours are longer in summer than in
winter.
This, too, would be built like a boat with the mast laid down (or a segment thereof, cut perpendicular to the keel).
> Using some sort of orbital mechanics to explain varying day lenghts
> vastly complicates things.
Only if you use the sun. In a clear night, you get Mastakos/Uleria as a very reliable timepiece. Always visible, crossing the sun path in 8 hours - four hours to meet Polaris, four hours down again.
> A simpler explanation is to make it
> mythic, and the sun simply really DOES take longer or shorter times
> to travel the same route depending on the season.
There is room for an easier, mechanical explanation which has circular paths for both Yelm and Lightfore which have an opposed up- -down movement and constant angular movement (wrt the circles, not the ground).
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