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[Snaake]

Does anyone know if the seasons are reversed if you embark in the "southern" hemisphere of the map? 

They are not as far as I've been able to tell.  While I dont think I've ever tried embarking on the far north or far south on the same generated world I've embarked on both northern and southern glaciers and they always started with spring on the first of granite. I sopose its always possible that this could be explained away by saying that the dwarves set their local calendar to the local seasons and have no knowlage of the far hemisphere from their location.   Because every world I've generated always goes from extream cold on one side to extream heat on the other it is somewhat logical to asume any world we gen only shows us 1 hemisphere and its possible theres a continent in the other hemisphere that we dont know about that has their first of granite on our first of limestone.   Personly I think its more likely that toady just hasnt goten around to simulating that aspect of the world yet.

I have seen cold-hot-cold worlds, they're more common but not guaranteed with the larger map sizes. But yea, dwarven calendar is fixed relative to seasons, I think.


To itg: I presume Cerol the werelizard doesn't dehydrate/starve because he's not a member of the fort? Or is it the transformation that resets his/her thirst/hunger counters?

Now I'm trying to think of stuff that either the werebeast or vampire repeater could be used for. Slow execution of prisoners via once per (lunar or calendar) month repeating spikes (vampire one could actually be set to patrol back and forth over a pressure plate for a more conventional "fast" repeater), periodically dropping trash down a chute, or magma down the trash chute to burn the magma, operating an atomsmasher regularly, refilling cisterns, sending off minecarts (that have come to rest on deactivated rollers), dropping magma into a prisoner disposal pit (prisoners get automatically sent there by a minecart double shotgun or something)...

The great thing about the vampire repeater especially is that if you build a complex of various pressure plates for him to trigger (give it plenty of doors so it's easier to safely add to), you can do pretty much whatever, even doing eg. all of the above ideas, each once or twice a year.

[Swonnrr]

Seasons are fixed, but tropical aeras simply have a "dry season", and a "wet season", wich could still give an idea of distance, if we consider the scorching aera to be the equator, and the freezing ones to be the pole.

[Tarqiup Inua]

To itg: I presume Cerol the werelizard doesn't dehydrate/starve because he's not a member of the fort? Or is it the transformation that resets his/her thirst/hunger counters?

I can confirm this... when adventurer transforms, he stops being hungry/thirsty

[Lielac]

itg...

wierd...

you're both such geeks

-sniffle-

Thank you for reminding me why I lurk in this community. It's because you guys are all made of awesome scientific nerditude.

[itg]

I actually rather like the way that a 13 month year, with 26 days for 11 months and 25 for 2, works out numerologically (yes, in magickal parlance), in perfect synchronicity with both lunar and solar calendars mathematically. (Even the max error in sync of 1 day for this arrangement is a neat, whole quantity!)

I may have to create a fictional mythos built around it! The potential there is incredible!

(One of the akward side effects of having studied "magic" as an aspect of human psychology, is that one ends up with a kind of cogitative dissonance, where one can see where "magic" would be applied in a circumstance, yet be perfectly grounded in objective reason and mundanity at the same time; having studied the how's and why's of magical traditions, I can comprehend the relationships those traditions attempt to create, while not actually believing in them. When such clearly phenomenal conditions appear, part of my mind creates such magical relationships, that my concious mind soundly rejects afterward.)

Having applied a little neural processing time to this set of numbers, a very powerfully profound basis for a numerological cosmology appears, rich with potentials.  Fleshing it out here would detract from the thread, but I WOULD like to point out that the indivisibility of the number 13 is NOT a fault in that respect.

(Today's numerologically magic numbers are: 1, 2, 5, and 13, where the number 2 is almost perfectly synonymous with raw magic, and the numbers 3, 6, and 26 have secondarily derived compound significance.)

To really make it complete, you should make slade the 11th month of the year, and adamantine the 4th.

If you guys really want to see the resulting numerologically based magical cosmology my brain seems intent on producing, I am sure we can find a way to present it. Perhaps the creative projects subforum?


*edit

Looks to me like toady's moon has an eccentric orbit. Let me see if I can calculate the eccentricity, assuming a perfectly circular planetary orbit around the star. (This would explain why the length of the lunar cycle changes slightly over the year, with the events always occuring on the same days each year.)

Both the numerology and the orbital calculations sound pretty interesting to me. Feel free to post it all in this thread, if there's nowhere else you'd rather put it.

If I were you, I'd start moon's orbit project by investigating a DF world's topology, if you don't know a lot about it already. For example, if you travel far enough east, do you end up on the west side of the map, or do you run into a wall? My money's on the second one, but I really don't know. I'm sure these questions have been answered somewhere on the forum, but if not you'd have to take an adventurer out there.

I'll also be interested to see how you handle different sized worlds. Will you treat them as different sized plots on one much larger planet, or as same-proportion plots on different sized planets?

Also, since it's a fantasy world, you could look into off-the-wall ideas like the hollow earth theory.

To itg: I presume Cerol the werelizard doesn't dehydrate/starve because he's not a member of the fort? Or is it the transformation that resets his/her thirst/hunger counters?

Both are reasons I don't have to feed him. The great thing about him being an outsider is that I don't have to worry about his feelings. Come to think of it, though, an insane werebeast would do the job just as well, so I take that back.

[wierd]

Ok, Without fully computing out the orbits (Weekend project!), and JUST working with the periodicity of the months and days between cycles...

here's a tentative numerological/cosmological/astronomical framework.

First up, the clearly and profoundly significant numbers, and why they are so.

(1) The number one is the primary ordinal. The fundamental unit from which all others spring. It is the mythic counter balance and origin to the indivisible number 13. (See 13). There is but the one earth, and its ending is also its beginning.

(2) This number represents mystery, the raw power of the esoteric and arcane. To fully explain why, we need to explain the rest of the cosmology, so more on that later. in a nutshell, it represents the unknown and unknowable, and equal but opposite quantities that are only distinct when viewed side by side. It has manifestations EVERYWHERE. (A left hand, and a right hand. The mirror symmetries of living creatures, and reflections in mirrors. Etc.) It is also associated with works and wonders on a cosmic scale. (there are 2 spheres in the sky, The moon and the sun, etc.)

(5) This number represents a count of days, or a cycle of measure for mortal and mundane creatures and tasks. (i'd expect a base 5 number system for ordinary tasks, like book keeping, or base 10, with special magical significance added, based on 5 and 2.) It represents physical labors, and processes. (See the section on gods and their devisions below.)

(13) This is the indivisible number of completion. A full turning of the world, and a manifestation of the divine world beyond the physical one, which reflects it.


OK then.

First up, we have a year laid out like this:

3 months with 26 days, then one month with 25. This is followed by 5 months with 26 days, and then a month with 25, followed by 3 months of 26 days. This creates a full year.

Significance, and magical thinking mode engaged:

This places the first month of 25 days on or near the spring equinox, and the second month of 25 days on or near the fall equinox. There are 2 such times of the year.

Each normal month is 5 counts of 5 days, plus one holy day dedicated to the patron god of that month. Each god has 2 axes of manifestation, and the first is celebrated in the daylight hours, and the second after nightfall. So, EG, on the month of Granite, the god of "Wealth" is represented, and on the holy day, all the pleasures of excess that wealth brings are celebrated-- but after dark, the sobering realities of poverty and the pains it brings are given religious devotions. These months all fall during times of the year when the day and the night period are of uneven lengths, as is fitting for the gods they patronize on those months. (Some align more with a positive daytime influence, and other align more with a negative night time influence, making the time spent in the devotions to each apropos to their roles in dwarven civilization and cosmology.) This is magically represented as a full count of counts of days, (5 weeks, 5 days each, representing a full cycle of toil) in observance of 1 god, and its twin axes of the celestial mystery. It is important to point out that these are the lesser gods more associated with mundane events and occurrences. (Things involving mortals, or the mechanical nature of the mortal world.)

Each month sees a cycle from full moon, to new moon, to full moon again. In this cosmology, the full and new moons are not what are considered magical. Instead, it is the 2 periods of half moon that are given significance. (This is a masterwork pigtail cloak made of master work pigtail cloth made by Urist McClothier, Masterfully dyed midnight blue with dimple dye by Urist McDyer. On the item is an image of crescent moons in pearl. The crescent moons are the symbol of the local dwarven civilization. Etc.) This is because these two cycles always occur each month, and are both equal, yet opposite, despite being identical. (Both are 1/2 moon. BUT-- One is the left side white, and the other the right side white.) The new and full moon phases are simply the extrema heralded by the 2 half moon phases, and mark the beginning and end of the month.

There are 2 months of 25 days, in which no holy day is observed. Instead, the entire month is held special, and takes place when the first period of day and night are of equal duration. Like the magical period of the half moon (which occurs twice a month), this time occurs twice a year, and both have equal periods of day and night-- but one heralds the ascent of warmth and life, and the other of cold and desolation, and conversely, the counter to their opposite, while being equal quantities. These months hold much magical significance, and are dedicated to the opposite halves of the same deep mystery. The number of days in these months is a perfect count of a count of days (5 weeks of 5 days, even) and taken together, add up to 2 counts of counts of days (50 days), dedicated to the 2 equal, harbinger gods who share a single axis of mystery. (These gods are unknown, and unnamed. It is presumed one is male, and the other female, but which is which is not known, as is appropriate for their sphere of mystery. Only standing side by side can they be discerned one from the other.)

This gives 11 mundane gods each with 2 axes of expression, and 2 special gods of mystery that occupy an obscured  single axis of power.

5 of those gods are strongly associated with beneficial mortal wellfare, which have months of devotion which align strongly with a daytime bias. (The summer months between the equinox months.) 5 of those gods strongly align with deleterious aspects of mortality, and have a strong nighttime bias. (Winter months.) At the winter solstice month, The most nighttime aligned god of mortal affairs is given devotions, The god of destruction and of fiery and bloody rebirth. (Armok, if you feel so inclined. ) This gives 2 counts of 5 gods, 2 gods of mystery, and 1 god of endings and origins, signaling a full turning of the cycle. (The god of destruction is also the god of creation; For through the destruction of the old is the new created, and the purpose of the new creation is to satisfy the will to destroy.) This makes 5 mundane gods of works of creation and benevolence, and 5 gods of decay and malevolence, 2 harbinger gods of equal mystery, and one god of origins and endings.  A count of celestial days of creation, and a count of celestial days of destruction, driven by 2 hands of 1 will, making an indivisible circle of 13 points.

Thus, are there 13 gods for one planet, and through the expression of one for the other, both are fully manifested in their fullest entirety.



It needs more thought, and more refinements, but it very neatly deals with all of the "problems" of the 13 month model, and paints a very vivid mythic backdrop for a very unique culture, that fits VERY well with many already existing world features. (Is it merely coincidence that there are TWO truely fantastical metals in the world, and that both are buried deep, and hold deep mysteries? How about how one is the harbinger of great fortunes, and the other of certain doom?)

Isnt magical thinking fun?

[itg]

That's impressively well thought out. I'd follow that religion if I were a dwarf.

So, as they're currently named in my calendar, the 25-day months are Hematite and Moonstone. Maybe they don't fit as well as adamantine and slade, but you might be able to do something with them. Hematite is an iron ore, so it represents a source of steel, the quintessential dwarven metal (adamantine being sort of transcendental in that regard) and a strong symbol of industry. Moonstone, on the other hand, is purely ornamental, associated with the heavens (including, obviously, the moon), and it is pretty strongly associated with the elves in some fantasy universes. Together, the holy months represent heaven and earth, dwarf and elf, two forces which are neither good nor evil, yet they are diametrically opposed.

Hematite is one of two metal ores in the calendar, and the other, Malachite, is the next month. Moonstone is one of two gemstones in the calendar, and the other, Opal, is the month after that. Two two-month pairs. Each holy month is followed by its counterpart. Coincidence?

[wierd]

Would it surprise you that this cosmology was nearly "instantaneous" in my subconscious, after seeing the numbers?

It quite literally grabbed hold and shook my rational mind by the hair. LOL. With some refinements, it would be very eloquent, and flawless in its self-refferential beauty. Everything that makes my rational mind want to curbstomp it into oblivion. LOL.

Having a conflicted nature, and reflecting upon it in silent contemplation has some very interesting pleasures sometimes.

[nanomage]

In my opinion, suggesting an eccentric moon orbit is wrong because high eccentricity would result in varying time intervals between the full moon and the new moon (which is not observed) and varying visible size of moon (which is not noted, but is likely not observed too because it would be mentioned otherwise)

EDIT: corrected some grammar

[wierd]

The eccentricity is very small, but is the only way to account for the different periods of time that some months have. (it varies by 2 days, if you actually count them.)

This means that either the moon speeds up and slows down, or the vector the moon travels changes, or both. Again, the eccentricity should not be very big. (and it has to be eccentric unless orbital velocity is exactly matched to mass. As the man in that thread points out, perfectly circular orbits are "Very goldilocks" , and that gravitational disturbances would make it not be circular anymore. Since the DF planetary system appears to lack other planets besides just the planet the dwarves and such live on, its orbit can be essentially circular, if plotted through the barycenter of the planet/moon system, and not the center of mass of the planet.  Incidentally, this would give an explanation for seasonal insolation differences without needing axial tilt at all, which would explain the curious lack of reversed seasons below the equator.

It is important that total angular momentum is conserved in such systems, but angular velocity can vary. As an orbiting body moves in closer to its companion, it speeds up-- and as it moves away,  slows down again.  A very slight ellipse would account for the discrepancy.

I haven't done the math yet, but will do so this weekend.  I think I have a better method of deriving the planet's volume worked up, using 2 points and a tangent line with an angle, where the first point is at the normal vector to the surface (90deg, at the thermal equator) and the second point is at 50% of the intensity seen at the equator on the same longitude, where sine 1/2 gives 30 degree angle of incident, and the distance between the points is an arc length. The plane through this measurement will hold the centerpoint of the sun, and the convergence of the angles of incident will define its location on that plane. That actually has fewer points to measure than the 3 points, 3 arclengths method. Though I may do both, to get a better idea of how much map distortion there is, and perhaps, derive what kind of projection the flat map is. (then I could properly map a DF world's geometry onto a sphere in my favorite CAD software. )

Regardless, the elliptical eccentricity is required. It will only be very large if the moon is VERY massive. (The closer the moon is to being exactly identical to the mass of the planet, the more the barycenter of rotation will be out in space away from the planet's core. The smaller it is compared to the mass of the planet, the more tightly constrained to the point of the planet's center of mass it will be, and the less eccentric the orbit. By measuring the eccentricity required to get the variance in periodicity of the moon's motion, we can derive the moon's mass, and if we assume it has similar composition to the planet, we can derive it's density, and thus it's actual size.)

[Eric Blank]

Wierd, you scare me. Quite often. I love the idea for the cosmology though, and the idea of trying to put maps of DF worlds on a sphere.

[itg]

The eccentricity is very small, but is the only way to account for the different periods of time that some months have. (it varies by 2 days, if you actually count them.)

Can you explain how you got that the periods of the months vary by 2 days? I count (by the dates I posted) 2 25-day and 11 26-day months, which is just what you'd expect from a constant orbital period of about 25.8, after you round to the nearest day.

That said, I like the idea of a very massive moon in a highly eccentric orbit. That would make for an incredible night sky. And some hardcore tides. Now that I think about it, the fact that those tides don't exist in game puts a limit on the mass of the moon, unless you'd rather just chalk it up to incomplete simulation.

[wierd]

Nature doesn't "round", since it is an analogue system.  In order for the days on which lunar events occur to remain fixed year after year, the system must be precisely balanced.

Because there are 25 days between periods for some months, and 26 days for others, and still in perfect sync, then the velocity of the moon must vary. With a circular orbit, that is impossible without violating angular momentum being a constant. (Without an elliptical orbit, the moon's phases would drift slowly over time away from perfectly consistent days each year.)

In reality, you are most certainly right-- toady just truncates the value as a rounding error. But, to get the same phenomenon in an analog system, you have to be more clever. The moon needs to speed up twice a year, then slow back down.

If you want an epic moon in the sky while still conserving all the math, you just alter a simple assumtion: the density of the moon is similar to that of the planet.

So far, it looks like the DF planets are smaller, and denser than the earth. That's a no brainer, we have something akin to electron degenerate matter down in the core! (Slade). If the moon lacks slade, or has it in a different proportion, the moon will be less dense, and will need a larger volume for the same orbital profile, making much bigger in the sky, for the same distances and velocities.

Making it more mundane, like our moon, would make it quite big in volume compared to its gravitationally dominant partner.

[itg]

Actually, I meant that the rounding is (probably) just in my list of dates. I recorded the date of the full moon every month, since that's all the game records, but I didn't mean to imply that the full moon occurred precisely at midnight on each day. In fact, I'm fairly certain, though I can't say for sure, that each full moon occurs at a different time of day. I strongly suspect that the number of hours between each full moon is constant.

[Larix]

Yeah, i can't find a 24- or 27-day month, either. That the period appears pretty much the same over the year doesn't exclude eccentricity, our own moon's time between two new moons varies between 29d 6h and 29d 20h (source: wikipedia), largely due to eccentricity of the moon's and the earth's orbits. It still averages out to ~29 1/2 days over every year.

The way the world map pans out to a plain rectangle suggests we're not looking at an actual equator and poles. The maps we're playing with could be a mere part of the world, or the whole world could be a torus. In the latter case, you should be able to 'wrap around' to the opposite end of the world by going past the edge, so clearly the world is flat. Probably a tabernacle.