The Campaign Builder's Guild

A planet which rotates once for every terrestrial month will have many affects on the world. In my world there is a translucent ring around the center of the planet, providing shadow to the equator and diffusing daylight all around the world. Even at midnight there is light equivalent to the darker end of dusk or twilight on Earth. Still the extended cycle will have many effects on life.

There will be few, if any, strictly nocturnal or diurnal creatures. Most creatures will need to operate equally well in bright noon light as they do in the dim nocturnal illumination. Many creatures will have developed echolocation, low-light vision, or some other heightened senses to cope with the long dark.

In addition there will be many effects on weather. With an axis of rotation almost perpendicular to its orbital plane, this world will have no notable seasons outside of day and night. The thick atmosphere also conducts heat well, keeping a more uniform temperature over the planet's surface. Even still, late at night it is significantly colder than it is during the day. Not cold enough for snow, probably more of a rainy season.

The tides will also change with daylight, especially since there is no moon to effect them, only the sun. This will cause them to be somewhat easier to predict, but they will also be less extreme and less frequent making them harder to use for trade purposes.

Plant life will need to be able to store energy for much greater lengths of time. With not enough time to shed leaves every night, most trees will remain green throughout the year. I'm not sure which changes would be required here.

Near the poles there is probably going to be a few species of birds who are able to glide on warm are currents fast enough to stay in continual daylight.


Any other thoughts on what effects this cycle would have, not just on the ecology, but also on the daily lives of the inhabitants of this world?

Quote from: PellanorA planet which rotates once for every terrestrial month will have many affects on the world. In my world there is a translucent ring around the center of the planet, providing shadow to the equator and diffusing daylight all around the world. Even at midnight there is light equivalent to a dozen of earth's full moon. Even still the extended cycle will have many effects on life.

So you don't have night at all, just daytime and a 'nighttime' that is, oddly enough, brighter than the daytime.

the reflectivity of the moon averages .12, meaning that 12% of the sun's light gets to us by way of it being bounced off of the moon. Average, of course. It gets bigger during the full moon, and even at the average a dozen of them all the time gives you a reflectivity of 1.44, or 1 1/2 times as bright as the sunshine. :D

I obviously don't think you would actually have that (although it would be AWESOME. For everyone except astronomers...), it's an interesting point. Night and day become irrelevant as terms, making way for sunny and shaded.

How would time inside of this night and day be kept track of?

ignore this... double post.

Quote from: PellanorThere will be few, if any, strictly nocturnal or diurnal creatures. Most creatures will need to operate equally well in bright noon light as they do in the dim nocturnal illumination. Many creatures will have developed echolocation, low-light vision, or some other heightened senses to cope with the long dark.

The tides will also change with daylight, especially since there is no moon to effect them, only the sun. This will cause them to be somewhat easier to predict, but they will also be less extreme and less frequent making them harder to use for trade purposes.
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Near the poles there is probably going to be a few species of birds who are able to glide on warm are currents fast enough to stay in continual daylight.
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Any other thoughts on what effects this cycle would have, not just on the ecology, but also on the daily lives of the inhabitants of this world?
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Well it's really needless to say that your inhabitants are going to be different. This environment is not an ideal one for mammalian bipeds (elves, humans, dwarves, etc... throw those out, they wouldn't make it to sentience here without major magical/deific help). You would see many more flyers and gliders with only the very largest creatures stuck on the ground. Make note that this can complicate a game since you have to realize that players are now likely moving on three axises instead of the normal two (x, y, and z as opposed to just x and y for non-flyers).

@Stargate525
I believe you are mistaken. While the reflectivity of the moon is .12, that is during the full moon. However the rings don't reflect 12x as much light as the moon (or 1.44x the light that hits them), but rather provide an amount of illumination as the full moon would were it 12 times larger.

Quote from: http://en.wikipedia.org/wiki/Moonlightwikipedia[/url][/i]

So in this case night time is only 41,667 times fainter than noon. 2.4 lx, just slightly darker than civil twilight (3 lx).

Quote from: Ninja D!How would time inside of this night and day be kept track of?

Same way as on earth probably, there would just be alot more or alot longer sections than on earth.

@Nomadic
Lots of really good ideas. Thanks.

As for what the rings are made of, I was thinking it would be some a bunch of shards of reflective material, or crystal or something like that. Possibly something that is somehow supernatural in origin. The rings are going to be fairly central to the religion supernatural aspect of the world, as the shade they provide at the equator keeps the planet cool enough that it doesn't form an oven, while providing the illumination at night that allows people to live through and survive the long dark.

As for the bipedal humanoids not showing up. I was thinking that there would probably be a lot of climbers, jumpers and gliders due to the thicker atmosphere. Primates like the Sifaka may have evolved, so we could have something similar to humanoids. I would like there to be on relatively "normal" sentient race, that's just easier for us to understand. Any suggestions on what one might be like?



The primary measure of time will of course be the day. There will probably be a few sections divided up based on how high the sun is in the sky at the time. Outside of that they don't have any really accurate measure of time. And for most people that's good enough. The weather is the most important thing for farmers, fisherman, and just about everybody else, as far as events in time to keep track of. I'm anticipating that most races will have adapted to take a bunch of cat naps throughout the day, rather than having their sleep schedule tied to any one event.

Adventures will probably all pick up the basics of "time magic", at least enough to be able to accurately measure the passage of time. Besides, I want time to be somewhat "fluid" in this world. Not sure how Ill get that to work, but not having a real static method of detailed time keeping should help that out.

Quote from: PellanorI believe you are mistaken. While the reflectivity of the moon is .12, that is during the full moon.

unfortunately, no. That was the average, a full-moon is significantly higher.

Quote from: PellanorHowever the rings don't reflect 12x as much light as the moon (or 1.44x the light that hits them), but rather provide an amount of illumination as the full moon would were it 12 times larger.

That's not exactly what you said above, but whatever. Keep in mind though, that even though the lux remains at or around 1, you're throwing out far more lumens since you've got more reflective area.

Like I said though, your world, I just hover around in it.

hmmm... random website may be wrong then. Whatever.

Let's rephrase it to say that the rings provide enough illumination to be roughly equal to earth at dusk/twilight.

Quote from: http://upload.wikimedia.org/wikipedia/commons/thumb/7/7f/Backlit_Saturn_from_Cassini_Orbiter_2007_May_9.png/800px-Backlit_Saturn_from_Cassini_Orbiter_2007_May_9.pngRings of Saturn[/url]

As you can see the light cuts off quite sharply and Saturn's rings are practically totally composed of ice (something that is highly reflective). This is why from the night side I doubt you would see more than a thin sliver of light arching across the sky. If you want the night side to be less of a night side and more of a shady side while still allowing it to get cold you are going to need a moon or two. There isn't a way around that outside of magic.

In regards to bipedal humanoids it just isn't something you will see, at least not familiar looking. The closest you would have would be spindly and streamlined with perhaps small flaps of skin for gliding. Probably something like an anthropomorphic lizard. You have chosen a very alien world and by that fact things will be very alien. This isn't a world that will be easy to adapt to for players who aren't willing to play something very different.

@Nomadic
Well I guess the rings are going to have to be magical then. No point in having a fantasy setting if we don't throw some magic in the mix :)

I like the anthropomorphic lizard you describe. Sounds fun :)

It's interesting how changing a few features of the world has such a drastic impact. I like that it'll really feel like a different world. Much thanks to everybody for helping me flesh it out.

Just an idea then. Make your rings phosphorescent. They give out their own mystic glow instead of reflecting/refracting other light. This will still work on your day side since they are blocking the suns light and aren't producing nearly enough heat (possibly none at all) to counteract the effect of their shade.

Quote from: NomadicJust an idea then. Make your rings phosphorescent. They give out their own mystic glow instead of reflecting/refracting other light. This will still work on your day side since they are blocking the suns light and aren't producing nearly enough heat (possibly none at all) to counteract the effect of their shade.

I agree with this. Not only would it look cool, the rings would slowly dim during the night until they're almost gone right before dawn (assuming your ring is geosynchronous.)

This looks like it could be really cool and fascinating to play with and in. I think you're off to a great start in your critical thinking approach and evident research checking along the way. Given the sheer number of "variations from the norm" it may prove useful to start embedding URLs to your info sources as you go, e.g. the online source you mention in reply for moonlight intensity. (Something I've only done occasionally but should probably start to do a little more often now for similar reasons.) Please don't take any of the following as arguments against/in discouragement of any of what you're proposing about your world. This is fantasy and as such can ultimately work any way you want it to. Even more, (please forgive me if I'm restating the obvious, but for purposes of this discussion I wish to ensure it is clear that:) "realism" and verisimilitude are not the same thing - and it is the latter which is most important. Achieving the latter however is often easiest if you take the former as far as remains convenient, then focus on the latter when realism starts to interfere with the effects you wish to achieve. Magic of course can establish alternative rationals at any point in the development process - so long as it behaves consistently as a "natural law" (even if a poorly understood one), verisimilitude will be maintained no matter how far you deviate from "reality."

In simple reality, under laws of physics, bio-chemical processes, etc., neither this planet, my setting, nor many others are at all likely to be physically possible, at least not as we describe them. (My own I'm reasonably certain would have to orbit the binary stars at a much greater distance, producing a much longer year, to maintain a viable climate for life as assumed/described. The cycle of glacial/interglacial periods moreover would probably grow far too cold and far too hot well before their peaks to support any life.) Again, magic can resolve this - the essential consideration will usually be that magic effects on the planet replace necessary physical factors - e.g., to have "green" plants (depending on light spectrum chlorophyll may actually reflect a different predominant wavelength to the viewers' eyes) you need a proper spectrum of light to facilitate photosynthesis, so either you have a magical (or "undiscovered"-by-our-world physical) source for such light where a normal physical one is absent or plant life functions much differently. The difficulty with the latter then is there will be a cascade effect of further considerations since photosynthesis is essentially a means of storing energy consumed not only by the plant, but by anything which consumes the plants and whatever consumes the herbivores on up the food chain.

 

QuoteA planet which rotates once for every terrestrial month will have many affects on the world.

I just want to be sure I understand the statement correctly as meaning the time span of a single axial rotation; from sunrise to sunrise = 24 x (28 to 30) hours with 24 x 12,13 hours daylight and equal night? Next - how long is a year in strict terms of planetary orbit around the sun? Planetary and solar mass are the critical factors - but then two choices arise from these. Earth mass orbits solar mass at a specific distance and velocity. Assuming for the moment that your planet and its sun are the same mass as ours then the year's length is a function of orbital distance (circumference can be derived from orbital radius) and velocity. Move the planet closer then you must also increase velocity proportionately in order to keep it in orbit. Move it faster at the same distance and it eventually breaks free, move it closer at the same velocity and it is eventually pulled into the sun - so with both masses roughly the same, the year is the same length or a lot shorter or a lot longer (covering less distance at a higher speed or more distance more slowly.) Tweaking mass of either or both celestial bodies will allow you then to play with orbital radius and velocity further. Your year can even be shorter than your day but the planet is probably pretty close to the sun - or super massive - enough to maintain earth orbit at a much higher velocity. Of course a more massive sun pushes orbital radii outward proportionately while a more massive planet increases gravity.

 

Quotethere is a translucent ring around the center of the planet, providing shadow to the equator and diffusing daylight all around the world. Even at midnight there is light equivalent to the darker end of dusk or twilight on Earth.

Some discussion of this of course has already occured. To throw in some slightly different suggestions - fibrous strands of material may carry light from end to end - imagine an old fashioned twisted fibre (hemp/sissel/coconut) rope made of bits of fiber-optic type material - one end of each fibre has to face the sun and the other end face the planet - the "rope" can of course spin around it's core causing ends to rotate around that core facing out then in. Alternatively (along the lines Nomadic suggests) a radioactive material forming a (dust to pebble size) particulate cloud of a photoreactive substance (like old glow-in-the-dark watch hands) might be actually circling the planet in the opposite direction of axial rotation, absorbing light  then emitting it as it passes into the planet's shadow. With no axial tilt the band cannot in fact directly reflect sunlight from its orbit above the planetary nightside to the planetary surface since the "back half" of the equatorial plane remains in planetary shadow regardless of distance from the planet. Even with a noticeable tilt the ring must be extremely large in order to actually be in sun light above the equator on the nightside of the planet. (The Roadstar around Panisadore's equator is of the second variety I've mentioned, and only bright enough to create a visible navigational reference - night navigators plot versus a line over the equator rather than points over the poles.) Either of these could conceivably cast a shadow over the equator since in the first case the fibre optic ends pointing at the planet over the day side run from strands terminating outward on the night side, hence carry no light, while those pointing outward on the dayside are carrying light around to the nightside, hence the rope blocks sunlight from passing through it in a direct line from sun to surface. A particulate cloud will like wise simply be absorbing photons - some may make it past, or be released before that point of the band has passed into planetary shadow, but only a small amount - the particles still act as a barrier to light in a direct line just as with the rope theory.

 

QuoteStill the extended cycle will have many effects on life./There will be few, if any, strictly nocturnal or diurnal creatures.

Yup - circadian rhythms overall are blown to hell and gone. Given the glandular (neuro-chemical, hormonal and many other) effects on most animal life this is a fact with incredibly far reaching implications. My best suggestion is dietary - healthy balance is maintained through acquiring the necessary chemicals derived from plant life - you've already got to mess with the process of photosynthesis - wrap numerous chemical derivatives of sunlight via plantlife into a tidy bundle. Starvation/dietary deficiencies can have some interesting side effects. . . Nomadic's suggestions re: hibernating plant life folding up at night are a good starting place as the chemical mechanisms producing some of these physical reactions  could be roughly analogous (plant sterol precursors) to the missing glandular chemicals. Circadian cycles could even be deliberately self-regulated in such a fashion within a certain range of physical/psychological tolerance. i.e., animals essentially choose when to sleep and consume a "sedative" containing plant (containing analogues to melatonin and similar chemicals) in order to do so, waking up as it is metabolized. If safe, and desirable, this can be repeated. Where/when unsafe/undesirable they may instead consume serotonin and related analogues (probably heavily buffered - or you'll have to call your setting Candyland and put a giant mirrorball and lightshow in the sky. It would be incredibly difficult to come up with any plotlines because everyone would be convinced they're in love with everything else. . .) Of course rolling like this for an extended length of time - even if well buffered, will eventually become debilitating, but animals would at least be able to seek a place of safety before choosing to sleep. Sleep, and sleep causing plants, could further serve to counter depletion of other body chems used to metabolize the activity producing plants - neither can be consumed for too long because the body requires constituents derived from the other to metabolize them or they stop working. (Sorry ravers, the DJ's gotta take a nap sometime.)

 

QuoteMost creatures will need to operate equally well in bright noon light as they do in the dim nocturnal illumination. Many creatures will have developed echolocation, low-light vision, or some other heightened senses to cope with the long dark.

To reframe this with a different emphasis, I think your concepts and their further implications may flow better if you start with the low-light adaptations as the "norm" or baseline. That is, normal vision for everything is suited to the night and different creatures adapt in various ways to the presence of brighter light. This will make even more sense if you have a lot of heavy cloud cover (I'll get to that and albedo value in a bit. . .) Essentially most things will tend toward "shade loving", more for heat adaptation, and protective (nictating) membranes to shield the eyes in brighter light. Looking at typical concepts of Drow culture specifically arising from their environment could provide some ideas for how sentient lifeforms behave then. One question arising through much of this discussion in regard to night side visibility is color saturation or absence - the world under moonlight tends to appear very grey shade - color tints/shades of the same value tend to be indistinguishable even if on opposite sides of the color wheel. If they are perceived more normally at night on this world, then during the day they probably appear extremely saturated and garish!

 

QuoteIn addition there will be many effects on weather. With an axis of rotation almost perpendicular to its orbital plane, this world will have no notable seasons outside of day and night. The thick atmosphere also conducts heat well, keeping a more uniform temperature over the planet's surface. Even still, late at night it is significantly colder than it is during the day. Not cold enough for snow, probably more of a rainy season.

By "thick atmosphere" are you referring to atmospheric depth (http://en.wikipedia.org/wiki/Atmosphere) (length of vertical column of atmospheric gases from planetary surface to edge of gaseous exosphere)? Or do you mean gases of greater density? Either produces greater atmospheric pressure - the weight of that column upon the surface, further varying with gravity (as a function of planetary mass). Or are you referring to denser cloud cover? While this last does insulate at lower altitudes (preventing warm air from rising away form the surface) it also reflects a lot of sunlight - how much is reflected is quantified as a planet's albedo (http://en.wikipedia.org/wiki/Albedo) value. This overall is not only a function of cloud cover (and different types of clouds at different altitudes have different values), but also a function of terrain - both how light or dark (blacktop versus sidewalk versus snowfield) and how flat or irregular the surface (angles of incidence directing reflected light in various directions). Constant (stable) very thick clouds will produce an overall cooler temperature beneath them while keeping that temperature more stable (warmer at night as described earlier, but average over an entire day/night cycle being cooler than without them). The physics involved in these considerations are extreme and far too complicated to try and produce a "realistic" set of different values. In terms of a viable planetary setting it may not be possible at all (part of what I was talking about at the very beginning)  - I would however recommend some cursory research to grasp basic primary principals and variables - how the systems react in general to changes in their parts then go with what's generally along the lines of the effects you want. Tweaking preceding concerns further can assist here - gravity, i.e. mass (basically determined by size if composition is the same as Earth) of the planet will influence a lot about the atmosphere. So will heat from the sun and weight of gases at various layers. More massive planets can hold lighter gases in their atmospheres. More solar heat will speed up molecular motion causing more gases to escape. If anyone know of a good meteorological modeling program that will let you play with these values please let us know! The Wikipedia links should be sufficient - any arguable inaccuracies I'm pretty sure will be at the level of detail/complexity to be irrelevant to our purposes in modeling a fantasy planet. . .  In all of the above (this paragraph) one major influence will be how much of the planet's surface is covered with water. Planetary albedo as a whole is pretty directly dependent upon this - not only due to a consistent amount of reflection since even if less than half the surface, this still is the greatest single set of consistent values in terms of both light/dark value and evenness of terrain. Further, it directly influences atmospheric water vapor exchange - again the single largest factor although vegetation also has significant influence (Rainforests perpetuate their own climates because of this; n a healthy rainforest, most of the water falling in rain is the same water that previously evaporated from that very same forest! Loss of surface area of a rainforest collapses the system when a critical value is reached - not enough moisture is released into the atmosphere above it to produce rainfall before the clouds have a chance to move away.)

The atmosphere however will not be sufficient to evenly distribute heat across your bands of latitude - lack of tilt causes extreme (though evenly progressing) differences in overall climatic temperatures. To compare with Earth the equatorial zone between the tropical bands (23.5 degrees) won't really change much - the sun is always pretty much directly above this zone year round in both cases. However, with no tilt the polar regions don't get warmed significantly (no melt off = changes atmospheric water exchange) instead will (if receiving the same overall light as Earth) probably remain frozen in small(er) polar icecaps with temps in the ares between these extremes a stable year round 33-70 degrees - slide this up gradually as you move closer to the 23 degree points. One reference I have states about a 54 degree tilt is required to create even temp distribution from equator to poles - that is, you've pushed the tropical bands to 54 degrees north and south.

 

QuoteThe tides will also change with daylight, especially since there is no moon to effect them, only the sun. This will cause them to be somewhat easier to predict, but they will also be less extreme and less frequent making them harder to use for trade purposes.

Pretty true here. Tides (http://en.wikipedia.org/wiki/Tides) are even more confusing and complicated than the preceding stuff(!) and in some places on earth the moon has little effect and the solar tidal cycle does - this is mostly related to features of the coastline and I haven't a clue how. Given the slow rotation of the planet the tidal changes will likely be even great, rather than less because the sun will have more time to impose its gravitational effects on the points of the planet's surface directly below them. However, this will be most pronounced at the equator and least at the poles. Also, because this is so slow you will have a semidiurnal cycle much like the moon produces - the solar component will clearly effect the opposite (nightside) point on the globe in the very same way the moon does on earth. The rise and fall will proceed very gradually and slack tides between the two motions will be long. Outside of coastal and wind effects the cycle will be quite predictable, occurring at almost exactly the same time of day and night all year. (High at noon and midnight, low at sunrise and sunset, all adjusted for coastal features, underwater terrain, etc.) In some ways mariners can take even greater advantage of them - they would probably have a huge impact on shipping since navigators would try as much as possible to actually benefit from them and to sail against them as little as is absolutely necessary. They would likely cause some distinct trade cycles to arise in terms of longer oceanic voyages (trying to "ride the tide") while coastal vessels will be predominantly lateen and gaff rigged to tack as much as coastal winds will permit, coupled with very shallow drafts and narrow beams to reduce drag as much as possible against strong tidal currents.

I hope this stuff is helpful. Ultimately, use the physics only as much as remains convenient - general patterns to explain general trends - you can get away with a lot by DM's fiat, especially with magic to fall back on.

A few things I think I can add. First off, I'm very impressed with the blend of fantasy and science fiction you seem to be going for. Although you're going in a very different direction than my setting, your quest for believability and a level of realism is similar.

Second off, I wouldn't worry about things being 100% accurate, just believable. An article from the D&D 4E designers brought up the issue of believability, and I've taken it as my mantle. IFM (It's F'en Magic) works to an extent, especially in big situations. There's a quote from someone about how people fall prey to a big lie more than a small one: just think about the way people believed the world worked in the past.

So here are some topics that I think are of importance:

Time: During the day, time is going to be measured by the position of the sun. I would have the main sentient race have an architectual tradition where there are many angles and beams in roof work, so people can use them as reference points. Clock towers could be tall towers with markers on them; to tell the time, you stand along the tower's shadow and look up at where the sun is. Even more simplistically, these clock towers could have courtyards around them with accurate times carved or tiled into the groundwork, showing specifics. I'd say that each "Day" would have 3 "weeks"; morning, noon, and evening, splitting the sky into thirds. Aside from the accurate clock towers (which I think should be infront of churches; the world is definately going to revere the sun and I believe the most powerful god has to be the Sun deity, though this depends on how your world's spiritual system works).

As for time at night, you could use the rings. They're going to be visible from all parts of the world except very close to the poles (but that's fine as I don't think the poles would be very habitable). I recommend having large objects in the rings (Saturn has protomoons and moons in its rings if I remember correctly). The ring would have its own rotational period, and I think this period should exist to help show the passing of "days". I also agree with the idea of a "glow in the dark" ring; then the level of light in the ring would determine the passage of time (though this would be harder to actually mark). I believe the ring has to rotate faster than the planet, though, for it to not fall in; I'm not certain though.

With the storms that would come with dawn and sunset, I think the Night should be represented by malevolent deity.

Plants: I don't think true plants would exist. I can see your world's plants being a fungus/plant mixture, using photosynthesis in the day to store sugars and feeding off those sugars in the night. With a half-month long day, I believe these plants would be able to store up considerable amounts of energy. But in addition to that, they would need to draw on energy from the soil as well.

I'm imagining the day having forests filled with broad leafed plants. As night falls, these plants soak up the water from the storms, their trunks and roots filling. They could even produce fruit at this time, which would provide food for creatures in the night and ensure dispersion of their seeds. When night falls, the plants would move all the water out of their leaves, causing them to shrink up. The plant would then feed off its sugar and water stores.

Additionally, as night falls the spores from nocturnal fungi would recieve enough water from the storms to grow. The forest would then be alive with massive mushrooms. I could see your world's trees actually being a communal relationship between a type of plant and a type of fungus, each providing each other during their lean times (there are many creatures on earth that do this). But it might be more fantastic to just splice them into the same organism.

I do like the idea of green plants in the day and mushrooms at night. Oh, and since the angle of the sun's rays doesn't change much, it might be possible and advantageous for plants to change color as the sun moves, one color for morning and evening when the sun is heavily angled, and one for noon when it is more straight on.

Races: First off, are you building this setting primarily for stories or for gaming? If you're building it for gaming, you're definately going to need a simply statted race with customization ("humans"). If you're building it for stories, you're going to want a race that people can easily identify with. I could be wrong, and I'm sure there are ways to get around this, but it just seems likely.

In another thread you said that sentience wasn't going to be evolutionary, that it is a gift from the gods. It seems that cold blooded creatures would either need to hybernate in the night or just wouldn't exist. Again, I'm not sure, so I'm just going off what makes sense to me (most of your readers or players are going to be reasonably clever; few are going to be experts in these fields).

I hope that something I said gets you thinking. Keep it coming, I definately have my eye on your work. If you are working on an RPG world, come to me if you need anything crunchy worked on.

Both Snarg and the Kapn' speak wise truths, listen and you will learn much (though ignore the Kapn's Freudian, slip funny as it was; cock towers... heh). In regards to the ring though...

Planetary rotation has little effect on whether a ring stays up, it's all gravity. The ring particles must maintain proper velocity in order to stay in an orbital pattern as close to 0 eccentricity as possible (they have to maintain a perigee that is higher than the atmosphere proper). However as this planet is rotating only once a month geosynchronous orbit isn't going to happen without crashing and burning (unless the planet is many magnitudes larger than earth and it's lighter gravity means it is in fact smaller). However that doesn't rule out telling time with them. They still have to rotate into the night side and depending on chemical makeup could indeed lose enough energy in that time to begin dimming as they approached the morning horizon.

Anyhow though, remember mister moonclaw's words. Verisimilitude always takes precedence over verifiable realism. Make things too complex and you will lose your players/readers. So listen to everything everyone has to say as it has real merit, but don't take things too far. Heh, you have to be really careful around me for that reason, I love all forms of science and real life simulation... so I sometimes forget that what's being designed is a game/story world... not a replica of reality.

Regardless though, best of luck. I will keep checking in and chucking in my two cents worth from time to time. Take or leave ideas as you desire. ;)

After I got home something occurred to me re: the ring(s) - they could also be a living organism - plant or fungus like, perhaps interwoven vine strands, which would store solar energy and release it when it passes into the shadow. Sentience would be an interesting option to explore as well. If it has other beneficial effects upon the planet and/or its atmosphere this could in fact be the body of an unusual preserving deity.

To expand on the Solar/Night deity idea - that would be pretty Zoroastrian in flavor I think - such a deity would fit in well as a mitigating (or "neutral") entity. A different way to approach the dichotomy which might also be interesting would be to have both deities display different aspects - kind of like the Rada and Petro rites of Vodoun (http://www.themystica.com/mystica/articles/v/vodoun_also_voodoo.html). The latter half of the day might well be oppressively hot and bright and the latter part of the night excessively cold and darker as the ring fades. Dawn and dusk would likewise have both positive and negative faces since they herald relief from either extreme but are also (perhaps even destructively) tempestuous. The ring could in a sense be the force that maintains the balance between the aspects of the other deities. They aren't exactly good/evil personalities, rather gentle and forceful - too much of either is detrimental.

Ring rotation that Kap'n mentions (re: it staying in orbit) would depend on how far from the planet it is and, of course, mass. If it's particulate it can be closer and slower than if it's solid since gravity is affecting the mass of each particle separately so it doesn't have to move as fast or as far out. The further away it is the slower it has to move to keep from breaking out of orbit. If it's solid however it could conceivably not have to rotate at all - it's own structural integrity prevents collapse into the planet. Gravity pulls on the whole thing equally and acts to make it stronger - much like the weight of a bridge structure pushing down on the supporting arches and making them even stronger.

Kap'n has made some good suggestions. (By the way Kap'n, I'm afraid you are quoting Hitler regarding one big vs. many small lies. . .) The menhir style clock towers'/giant sundials idea would work pretty well as long as you have no "wobbles" (Surviving remnants of such produced by ancient Earth cultures are no longer entirely accurate - recalibration is required  - but that is the result of many centuries' slight variations.) Another thing you could do based on his suggestion of plants changing color is to use that effect to tell time. Floral clocks (http://scribalterror.blogs.com/scribal_terror/2007/02/flower_clock.html) were attempted in the 19th century using species of flowers which open at different times of the day. None have ever really been practical as time keeping, though it can make a garden constantly change through the day. Having species on your world that change in a variety of ways at different times can be as accurate (or not) as you wish. Night plants could likewise demonstrate visible changes through the course of the night, or timekeeping could occur by tracking temperature variance - a night that long would probably show a steady drop (even if remaining in a comfort zone throughout) which could be measured.

A couple of decent references that I've found helpful are the World Builder's Guidebook (old 2nd ed. pub. from 96 - not system specific tho and still available via Amazon (http://www.amazon.com/Builders-Guidebook-Advanced-Dungeons-Dragons/dp/0786904348/ref=sr_1_1?ie=UTF8&s=books&qid=1217065358&sr=8-1). This is especially useful for mapping - comes with a number of blank map formats. Also the free excerpt from Expeditious Retreat Press' A Magical Society: Ecology and Culture, A Magical Society: Guide to Mapping (http://e23.sjgames.com/search.html?keywords=&publisher=Expeditious%20Retreat%20Press&price_lo=0&price_hi=0&sortby=alphaAZ). The City Guide is also excellent - I've been finding it very helpful (along with the city section of World Builder's . . .) in developing Salis Freeport. I haven't picked up the two books they're taken from but may well end up doing so.

Example maps from WBG:
(//../../e107_files/public/1217066242_541_FT52647_world_.jpg) (//../../e107_files/public/1217066242_541_FT52647_world.jpg)

(//../../e107_files/public/1217066242_541_FT52647_s1_.jpg) (//../../e107_files/public/1217066242_541_FT52647_s1.jpg)

Hah, wow, that's a typo. Thanks for pointing it out Nomadic; I blame it on my pain killers.

Quote from: Snargash MoonclawRing rotation that Kap'n mentions (re: it staying in orbit) would depend on how far from the planet it is...

http://www.traipse.com/earth_and_moon/earth_and_moon.gif[/img]

Of course remember that as long as it seems realistic the old "a wizard did it" is perfectly fine. Anyhow I will stop babbling on.

Wow, lot's of great replies over the weekend.
I'll start by trying to answer a number of the questions that I've seen pop up.

I just want to be sure I understand the statement correctly as meaning the time span of a single axial rotation; from sunrise to sunrise = 24 x (28 to 30) hours with 24 x 12,13 hours daylight and equal night?
That sounds about right.

Next - how long is a year in strict terms of planetary orbit around the sun?
As long as it needs to be. Since there's very little planetary tilt the "year" will have next to no affect on game play. I'll just end up figuring this number out at the end as a bit of "trivia", based on whatever other requirments we need.

By "thick atmosphere" are you referring to atmospheric depth? Or do you mean gases of greater density?
Hmmm... I'm not totally sure. You know how the air is "thinner" up at the top of Mt Everest compared to sea level? Well I want the air at sea level in my game to be that same amount of difference again.
ie.
Everest: 0.3 atm
Sea Level: 1 atm
Sea level my planet: 3.4 atm

So this could be made up in part by having greater atmospheric depth or greater density, or a bit of both.
The mainreason I'm looking for the thicker atmosphere is to make flight easier, and allow more oxygen for cool stuff to evolve.

Or are you referring to denser cloud cover?
This world will likely end up with thicker cloud cover as well. It'll be less massive, so probably closer to the sun than earth. I think that the denser cloud cover should help to reflect some of the light, and insulate the planet at the same time.

In all of the above one major influence will be how much of the planet's surface is covered with water.
The planet will likely be apx 50-60% water, though with less huge ocean and much more small scattered seas.

First off, are you building this setting primarily for stories or for gaming?
Gaming. The human-like race that's easy to play is something I'm keeping in mind.

Anyway, I'm going to do some work putting together a bit of a summary of what I like best, and areas where I think we still need more work. I'll post it later today (hopefully).

Planet Details
Name: ??? (I hate coming up with names. Any suggestions?)

Mass: 57.6% that of earth [3.4408×10^24]
Size (radius): 80% that of earth. [5,096 km]
Density: 112.5% that of earth. [6.205 gm/cm^3]
Gravity: 90% that of earth. [8.83 m/s^2](feel free to double check my math)
Sidereal rotation period (http://en.wikipedia.org/wiki/Rotation_period): 3278.9% that of earth [32.7 d]
Equatorial rotation velocity: 2.5% that of earth [11.33m/s]
Surface pressure: 340% that of earth [344.42 kPa (http://en.wikipedia.org/wiki/KPa)]
Surface area covered by water: 60%

Albedo: ?

Surface temp in Kelvin (http://en.wikipedia.org/wiki/Kelvin):
   min: ?
   mean: 10 K warmer than earth (297 K)
   max: ?

Celestial Properties
No moons.
Large rings around the center of the planet shade the equator and provide illumination at night. Likely phosphorescent and possibly magical in origin.

Geology
I have no idea what the make up of the planet should be. Probably fairly similar to earth, with a large molten iron core.
Since it is more dense, I'll probably introduce some more "heavy metals" like adamentine, and other such fun fantasy stuffs.

Topography
Since there are no tectonic plates the topography is very different than that of earth.

The surface is relatively flat, with fewer great mountain peaks and ocean depths.
3% - Mountain peaks > 2000m above sea level.
12% - Highland plateaus 500m to 2000m above sea level (3-4 "mini continents").
25% - Archipelagos (http://en.wikipedia.org/wiki/Archipelago) less than 500m above sea level.
15% - Shallow seas of depth <= 200m
20% - Ocean of depth 200m to 500m
20% - Ocean of depth 500m to 1000m
5% - Ocean of depth > 1000m

Climate
There are a few major climate belts.

The Equator is a fairly small region in continual shade due to the rings. This causes the average temperature to be slightly cooler during the day then the neighbouring tropical belts. Also being directly under the rings this area is the best illuminated at night, providing the least change from day to night of any of the climate zones, outside of the poles. Most life in this region is adapted to the low light, with few plants relying on Photosynthesis (http://en.wikipedia.org/wiki/Photosynthesis).

The tropics are the areas near the Equator that are not shaded by the rings. These are the hottest parts of the world, which receive the most sunlight during the day and a large amount of illumination during the night.
Tropic Archipelagos are typically rain forests which have evolved to absorb the most sunlight during the day, and rain at night. These broad leaf trees can reach heights much greater than those found on earth.

I'm not really sure what the other climate areas would be like... I like the idea Cloud forests (http://en.wikipedia.org/wiki/Cloud_forest) along with some highland Savanna (http://en.wikipedia.org/wiki/Savanna), though I'm not sure how those would work with the geology.

Flora
Mycorrhiza (http://en.wikipedia.org/wiki/Mycorrhiza) will be very important in sustaining plant life.
It looks like most forests would be Broad Leaf (http://en.wikipedia.org/wiki/Tropical_and_subtropical_moist_broadleaf_forests) during the day and Fungi (http://en.wikipedia.org/wiki/Fungi) at night.

How would Plains and Savanna work here? I think we could certainly find plenty of grasses, since they can grow in practically any climate. Also since they often grow in areas with only occasional rainy seasons, or in areas where they spend months buried under snow, they should be able to adapt fine to the longer day/night cycle.

I think a lot of the flora would have to grow in spurts as well. I imagine there could be a lot of really cool flowers that follow the sun and what not.

I also need to think of what could grow in Water. The Coral Reefs might be too sensitive to temperature change (A rise in temperature of 1-2 degrees Celsius for 5-10 weeks or a decline in temperature of 3-5 degrees Celsius for 5-10 days has resulted in a coral bleaching event. source (http://en.wikipedia.org/wiki/Zooxanthellae)) to do well, which is disappointing.

Fauna
There's going to be a wide variety of animal life on this world.

Any Cold-Blooded (http://en.wikipedia.org/wiki/Cold_blooded) creatures are going to be on a very short lifespan cycle, probably only ever living for a single day. They will be born with the warmth of dawn, and lay their eggs as the sun sets, and die out during the cold of night. Hmm... I wonder if it would be possible to have these guys go the entire day without sleeping, and how big they would be able to get. They could be a rather entertaining pest if there's enough of them and they can grow big enough.

Warm-Blooded (http://en.wikipedia.org/wiki/Warm-blooded) creatures will need to be able to feed both during the day and at night, or be able to hibernate. This means almost all of them will be adapted to the low light of nighttime. Of course they'll also need to be able to function during the day, so we'll need to avoid traits such as overly sensitive eyes that would be overloaded by full sunlight. Many creature will likely evolve Tapetum_lucidum (http://en.wikipedia.org/wiki/Tapetum_lucidum) so that they can see better in the lower light night time environment, though this has the downside of reducing the overall quality of eyesight in bright light conditions. Echolocation, along with heightened sense of hearing, smell and touch (ie. whiskers) will all be important in functioning both at day and during night.
Hibernating creatures will fall into two categories, diurnal (http://en.wikipedia.org/wiki/Diurnal_animal) and nocturnal (http://en.wikipedia.org/wiki/Nocturnal). Both will need to be more adapted to their respective light conditions than most creatures, to make up for the extra vulnerability of hibernation. These creatures will also
need to be smaller so that they can more easily conceal themselves for their period of hibernation. Another possibility might be heavily defended creatures like Armadillo (http://en.wikipedia.org/wiki/Armadillo).

Insects are going to be huge, both in numbers and in size. I'm thinking that I'll want a few Superorganisms (http://en.wikipedia.org/wiki/Superorganism), probably one of which will be sentient (though certainly not a player race!)

I think Dinosaurs and Birds would both fit very well into this ecosystem. I'll probably have Dinos as the big herd animals of the world, roaming the highland plateaus. The carnivores will mostly have evolved into birds of prey. There will be many sea birds that live in the high cliffs of the plateaus.

I'm not sure what kind of marine life there will be on this planet either.

There's also going to be a variety of Dragons. See my other topic (http://www.thecbg.org/e107_plugins/forum/forum_viewtopic.php?52632) for more details on them.

Another thing I want is some kinda critter that can feed off the extreme "spirit energy" that sentient beings have. Possibly something that can form a symbiotic bond with other creatures as well.

Oh yeah, and I love symbiots, so if anybody has any cool symbiot ideas, let me know :)




Well I think that's a fairly good summary for now. I'll need to spend more time polishing everything, of course, as well as add some of your suggestions that I liked but didn't get around to including.

Well, start with Flora, since this is largely the basis of the food chain. (You might also consider algae-based food chain too.)

The ultimate energy source for the food chain is usually sunlight. (Even here on earth, there are some ecosystems fed entirely by geothermal, though.) So you'll probably want photosynthetic plants. But they'll face a problem - very low light for earth-weeks at a time. So they'll need adaptations to this.

First, you might have some night-plants. They'd need to spread huge leaves out to capture enough of the diffuse light, but they'd have the advantage of lower competition since most plants would be day-plants. So they might grow as vines on tree-like day-plants, and when the day-plants go dormant at night, the night-plants sprout out big delicate tendrils that gather the diffuse ring-light to fuel their own growth.

Second, the day-plants would probably need some large root networks or pods in which they store nutrients derived from the sun during the long day. Then they'd go dormant (possibly even retracting underground) during the night. (Being fungal at night doesn't really help, because they generally exist by consuming the detritus of photosynthetic plants. So you still need the photosynthetic plants at the base of the food chain.)

Some plants could grow very quickly in the day, only to drop all their leaves every night.

If plants are generally not growing at night, they'd probably be at risk to herbivores during that time. So they'd probably evolve some pretty hefty defenses. Fronds might retract into hard, protective husks. They might evolve chemical defenses like potent alkaloids. Or they might end up in symbiotic relationships with fungi, insects, or the like that protect them during the long night.

Photosynthetic algae would face similar issues, but the range of solutions might be quite a bit wider. You could have big underwater aquatic "plants" that exist symbiotically with giant algae mats - at night the plant harbors a few of the algae, which are released in morning to spread and multiply into the giant mats, and at night the mats die out, feeding the plant that gives them refuge. Some algae could form spores of some kind to last out the darkness. They could drift the seas, following the sun or just blooming whenever the sun touches them.

The animals that feed on these plants could be even more bizarre, but that is a topic for another day.

Quote from: http://en.wikipedia.org/wiki/Rotation_periodSidereal rotation period[/url]: 3278.9% that of earth [32.7 d]
Equatorial rotation velocity: 2.5% that of earth [11.33m/s]
Surface pressure: 340% that of earth [344.42 kPa (http://en.wikipedia.org/wiki/KPa)]
Surface area covered by water: 60%

Albedo: ?

Surface temp in Kelvin (http://en.wikipedia.org/wiki/Kelvin):
   min: ?
   mean: 10 K warmer than earth (297 K)
   max: ?

Celestial Properties
No moons.
Large rings around the center of the planet shade the equator and provide illumination at night. Likely phosphorescent and possibly magical in origin.

Topography
Since there are no tectonic plates the topography is very different than that of earth.

The surface is relatively flat, with fewer great mountain peaks and ocean depths.
3% - Mountain peaks > 2000m above sea level.
12% - Highland plateaus 500m to 2000m above sea level (3-4 "mini continents").
25% - Archipelagos (http://en.wikipedia.org/wiki/Archipelago) less than 500m above sea level.
15% - Shallow seas of depth <= 200m
20% - Ocean of depth 200m to 500m
20% - Ocean of depth 500m to 1000m
5% - Ocean of depth > 1000m
[/quote]Photosynthesis[/url].

The tropics are the areas near the Equator that are not shaded by the rings. These are the hottest parts of the world, which receive the most sunlight during the day and a large amount of illumination during the night.
Tropic Archipelagos are typically rain forests which have evolved to absorb the most sunlight during the day, and rain at night. These broad leaf trees can reach heights much greater than those found on earth.

I'm not really sure what the other climate areas would be like... I like the idea Cloud forests (http://en.wikipedia.org/wiki/Cloud_forest) along with some highland Savanna (http://en.wikipedia.org/wiki/Savanna), though I'm not sure how those would work with the geology.
[/quote]Mycorrhiza[/url] will be very important in sustaining plant life.
It looks like most forests would be Broad Leaf (http://en.wikipedia.org/wiki/Tropical_and_subtropical_moist_broadleaf_forests) during the day and Fungi (http://en.wikipedia.org/wiki/Fungi) at night.

How would Plains and Savanna work here? I think we could certainly find plenty of grasses, since they can grow in practically any climate. Also since they often grow in areas with only occasional rainy seasons, or in areas where they spend months buried under snow, they should be able to adapt fine to the longer day/night cycle.

I think a lot of the flora would have to grow in spurts as well. I imagine there could be a lot of really cool flowers that follow the sun and what not.

I also need to think of what could grow in Water. The Coral Reefs might be too sensitive to temperature change (A rise in temperature of 1-2 degrees Celsius for 5-10 weeks or a decline in temperature of 3-5 degrees Celsius for 5-10 days has resulted in a coral bleaching event. source (http://en.wikipedia.org/wiki/Zooxanthellae)) to do well, which is disappointing.
[/quote]Cold-Blooded[/url] creatures are going to be on a very short lifespan cycle, probably only ever living for a single day. They will be born with the warmth of dawn, and lay their eggs as the sun sets, and die out during the cold of night. Hmm... I wonder if it would be possible to have these guys go the entire day without sleeping, and how big they would be able to get. They could be a rather entertaining pest if there's enough of them and they can grow big enough.

Warm-Blooded (http://en.wikipedia.org/wiki/Warm-blooded) creatures will need to be able to feed both during the day and at night, or be able to hibernate. This means almost all of them will be adapted to the low light of nighttime. Of course they'll also need to be able to function during the day, so we'll need to avoid traits such as overly sensitive eyes that would be overloaded by full sunlight. Many creature will likely evolve Tapetum_lucidum (http://en.wikipedia.org/wiki/Tapetum_lucidum) so that they can see better in the lower light night time environment, though this has the downside of reducing the overall quality of eyesight in bright light conditions. Echolocation, along with heightened sense of hearing, smell and touch (ie. whiskers) will all be important in functioning both at day and during night.
Hibernating creatures will fall into two categories, diurnal (http://en.wikipedia.org/wiki/Diurnal_animal) and nocturnal (http://en.wikipedia.org/wiki/Nocturnal). Both will need to be more adapted to their respective light conditions than most creatures, to make up for the extra vulnerability of hibernation. These creatures will also
need to be smaller so that they can more easily conceal themselves for their period of hibernation. Another possibility might be heavily defended creatures like Armadillo (http://en.wikipedia.org/wiki/Armadillo).

Insects are going to be huge, both in numbers and in size. I'm thinking that I'll want a few Superorganisms (http://en.wikipedia.org/wiki/Superorganism), probably one of which will be sentient (though certainly not a player race!)

I think Dinosaurs and Birds would both fit very well into this ecosystem. I'll probably have Dinos as the big herd animals of the world, roaming the highland plateaus. The carnivores will mostly have evolved into birds of prey. There will be many sea birds that live in the high cliffs of the plateaus.

I'm not sure what kind of marine life there will be on this planet either.

There's also going to be a variety of Dragons. See my other topic (http://www.thecbg.org/e107_plugins/forum/forum_viewtopic.php?52632) for more details on them.

Another thing I want is some kinda critter that can feed off the extreme "spirit energy" that sentient beings have. Possibly something that can form a symbiotic bond with other creatures as well.

Oh yeah, and I love symbiots, so if anybody has any cool symbiot ideas, let me know :)
[/quote]

All cool ideas. However remember that cold-blooded creatures could survive just fine here. The thicker atmosphere that makes your poles less severe means it takes longer to cool down. So instead of a reptile losing heat and being forced into hibernation at the onset of night, it could probably keep going for several days (possibly as long as 5-10) before it got too cold and it had to slow down. Even then the temperatures wouldn't be cold enough to stop a reptile dead. At worst they would have to hibernate out the last 2-3 "days" of night, waking up after the first or second "day" of light warmed the place up enough for them.

Symbionts are also a very good idea here. The trees being a good example (as well as snakefing's plankton/algae combo). This works for either plants or animals of course. You could have creatures that thrive in the day but are helpless at night that protect and are protected by something that the opposite is true for.

Giving an example perhaps you have a snake like creature that thrives in the daylight but goes dormant very quickly with temperature shift. It's body is home to a type of fungus that is helpless in the day as the heat messes with its ability to produce defensive chemicals. So during the day the snake protects it by letting it hitch a ride on its back (and letting it harvest its energy from the excess the snake has). During the night the snake goes dormant and the fungus it able to use starlight/ringlight to synthesize enough energy for itself. This means it becomes highly poisonous. The toxins of the fungus protect the snake while it sleeps. And so the cycle continues...

Hmm - there are actually a lot of problems cropping up here that will pretty much necessitate establishing a magical field displaying some consistent "natural laws or properties" to counter those of physics - or you will result in something alien to the point of being nearly incomprehensible (at least for anyone attempting to play it). If you back up a little while to a relatively simple model which behaves as you describe and then gradually looking at the effects of other factors in the model, this shouldn't be insurmountable - there are just some inherent contradictions which will have to be "counterspelled" as you go (and a few of them you may be able to simply eliminate from the initial physical model before waving the divine magic wand).

One of the basic factors is mass itself. If you want a planet which is smaller in volume (not including atmospheric volume here - just the size of the solid/liquid ball itself) than Earth and more dense you can't also have a lower mass. Mass and density are functions of the overall atomic make-up of the planet. This will later effect atmospheric pressure (but the atomic/molecular content of that atmosphere will then come into play) but for now we're basically determining the amount of gravity the ball can exert. Overall (sum total of) atomic mass present determines how much gravitational force it exerts (size doesn't matter unless the gods have issues of inadequacy). So - if mass is 57%, gravity is as well - but still only referring to the ball (as if no atmosphere). Overall mass and gravity of the planet exerted upon the material of the orbiting ring = solid ball + atmosphere (and that much gas does have a lot of mass to consider later). Density of the ball is likewise a direct result of atomic composition. If it's more dense than the Earth, regardless of size and mass, as this is proportional, it is generally made up of denser (atomic) material. You actually need an overall composition that is stepping up your "average" on the periodic table (http://en.wikipedia.org/wiki/Periodic_table_(large_version)). The good news is that this can't possibly be reasonably calculated - ballpark percentages of iron, etc. could be massaged a bit but you don't in fact need to do more than that - simply state that there's more X (denser element) and less Y and call it good. Eyeballing the table and assuming you want to keep the planetary core similar then I would suggest substituting some of that iron with molybdenum and tungsten in the molten core and perhaps even in the solid ores - essentially adding rather uncommon to rare metals (Earthwise) used to create ferrous alloys - on your planet more common and even needing to be refined out of the ore somewhat (moly-steel uses only a slight amount of the metal to make steel incredibly tough).

NB - sorry, but tectonic plates are an unavoidable physical effect of the molten core. The molten core is essential to planetary spin. You might consider solidifying it - I don't know the effect this would have on spin but you need a rational to slow it down anyway - magic would almost certainly need to fill in here - the question is how much.

What we are producing here however ultimately becomes much greater mass and gravity compared to Earth when we add an atmospheric layer - total gravitational force of the planet exerted on the ring (and the sun - this actually does effect the calculation in reality - not enough to bother with here - just realize that whenever something exerts a gravitational pull upon an object, that object, no matter how miniscule, also exerts a gravitational pull upon the first object).

Looking at atmospheric pressure then - this = weight of the perpendicular (to planetary surface) column of gas (= molecular mass of constituent elements x gravity) at the particular point and altitude where the measurement is being taken. There are two significant factors to consider here. Not only are there more molecules in the column at lower altitudes, but the additional molecules are also themselves heavier - both of these I think you were aware of when you answered my question about atmospheric density with regard to altitude. The question I have for you now however, is actually regarding the elemental makeup of the atmosphere. Again, comparing to Earth we have to look at the necessity of the oxygen/nitrogen content as well as the O2/CO2 exchange effect of photosynthesis. (If you step away from that process with regard to storing sunlight as calories in plants and play with other biology, you still need to look at oxygen exchange before doing so I'm afraid.) Going back to the Periodic Table we run into other problems producing a heavier/denser atmosphere. A Chlorine (Cl2) atmosphere will be about twice the surface pressure at sea level - and toxic. Beyond that you have to look at Noble gases - nonreactive (so they can't offer any sort of respiration to a biological organism) and monatomic - a molecule consists of a single atom only - so you need an atmosphere containing a lot of Krypton. Of course if the organisms are simply unaffected by this then it won't (being a noble gas) interfere with the respiration of any O2 and CO2 present - you could have your heavy/dense sea level atmosphere, I just have no idea what effect the presence of that much krypton gas actually would have on your life forms. (Personally, I'd be more inclined to fiddle with this than a chlorine atmoshpere. . .)

The odd thing about using atmospheric mass to raise your total so as to keep the mass of the ball itself low is that your atmospheric layer becomes thinner in terms of miles above the surface. When the (solid) planetary mass is reduced it is then unable to retain the less massive gases composing the outer layers of the atmosphere - all the gasses composing the atmosphere of course tend to settle - hence the "thinness" of air at high altitude. Less pressure due to shorter column but more to the point, more lighter gases and less oxygen. Avogadro's Number is a constant after all - the two factors just mean the atoms aren't packed so tightly. The part that really matters here is that heat exciting the molecules (Atoms really - at high altitudes we're dealing w/noble gases) causes them to move at escape velocity much more readily if the solid planet below is unable to exert sufficient gravity to hold them! If your planet is less massive/lower surface gravity than earth than your atmosphere will contain significantly less amounts of lighter gases - and consequently extend far less from the planets surface. Massaging these various factors can certainly help produce a world in which flight is quite common however.

A couple of things. First off, making a solid core will eliminate your magnetosphere, meaning the planet will be bombarded by bad radiation. You'll need something to shield this.

As for sleep cycles, look into how deep sea creatures and cave dwellers who never leave sleep. i'm sure there's research on that.

Quote from: Kapn XeviatA couple of things. First off, making a solid core will eliminate your magnetosphere, meaning the planet will be bombarded by bad radiation. You'll need something to shield this.

Interesting - I wasn't aware of that factor, assuming the magnetosphere to be pretty much entirely the result of the solid deposits creating the magnetic poles. (It may be unrelated to that phenomenon entirely, I don't know. . .) If it weren't for the oddity of declination I would expect that the deposits and the molten iron core are not coincidental, but have basically assumed them to be so. (I haven't given significant thought yet to such polarity, but need to look at it in Panisadore as well with regard to navigation at the very least.) Can you give a thumbnail explanation of how this works?

Yea the Kapn is right. The magnetic field of a planet with an earth like core draws its power from the liquid outer core's generation of electrical currents (the Earth is basically a giant electromagnet... tons of molten metal spinning around at high speed.... yada yada... you get the point). The heat of the core surpasses the point at which iron loses it's magnetic properties (Curie point I think it was). Thus the magnetism cannot be drawn simply from having a magnetic material.

In theory you could have a solid core that could pull it off. However that is a highly theoretical one and I cannot think of any way to do it without magic.

So the magnetic polls don't actually have anything to do with the Earth's electromagnetic field since that's caused by the motion in the core - separate cause of separate effect; evidently the field so produced likewise has no effect on the magnetic polarity either, or does this establish the polar directions of the flow of that electormagnetic field?

The spinning of the core produces a dynamo effect that generates the magnetic field of the earth. The magnetic poles just show how the dynamo is oriented. The location of the magnetic poles is not fixed - they wander about quite a bit on geologic scales.

In fact, there have been occasions where the dynamo has reversed itself and the magnetic polarity of the earth has flipped 180 degrees. This can be seen, for example, in the alignment of magnetic crystals in the sea floor that crystallized from lava at different times.

Now, in a fantasy world, you may not have any magnetic fields, no cosmic radiation, etc. Or the fields could be the residue of demonic energy. Or whatever you want. These kind of things can fairly easily be hand-waved away. It just depends on what you want, what you want your players to pay attention to, and how much you want these things to be consistent with each other.

Something worth mentioning, a lot of this world is based on what Venus (http://en.wikipedia.org/wiki/Venus) might look like, were it to have a livable atmosphere, faster rotation speed and of course, life. I suggest reading the wikipedia article as it goes over the magnetic field, lack of tectonic plates, etc...

For protecting the planet from cosmic radiation, I think that the "mystic properties" of the rings will take care of that bit, to enhance the otherwise weak magnetic field that this planet will have.

Quote from: snakefingThe spinning of the core produces a dynamo effect that generates the magnetic field of the earth. The magnetic poles just show how the dynamo is oriented. The location of the magnetic poles is not fixed - they wander about quite a bit on geologic scales.

In fact, there have been occasions where the dynamo has reversed itself and the magnetic polarity of the earth has flipped 180 degrees. This can be seen, for example, in the alignment of magnetic crystals in the sea floor that crystallized from lava at different times.

Now, in a fantasy world, you may not have any magnetic fields, no cosmic radiation, etc. Or the fields could be the residue of demonic energy. Or whatever you want. These kind of things can fairly easily be hand-waved away. It just depends on what you want, what you want your players to pay attention to, and how much you want these things to be consistent with each other.

The drift isn't surprising, although I wasn't aware of it nor had I considered it. I haven't ever looked closely into the physical nature of the deposits - in geological time scales a lot of stuff varies radically that we haven't been around long enough to observe directly - and some stuff has only become apparent relatively recently such as recalibrating observed celestial phenomenon - identity of the pole star and precession of equinoxes. The polarity reversal I have been aware of - many in the "New Age community" are making a big deal of this and predicting a reversal approaching quite soon (among other phenomenon). When you say "the dynamo has reversed itself" are you only remarking on the polarity - or reversing the actual direction of spin (which would explain why the polarity reverses) within the core? I'm particularly curious about that - one of the more well known/published New Age prognosticators, who is a geologist, asserts that the earth itself is slowing in rotatation and will eventually stop momentarily and then actually start spinning in the opposite direction (and claims it has done so in the past). I find this a bit harder to swallow, but hesitate to say it's impossible - not sure of the physics involved to be absolutely certain - on the other hand, the motion of the core is something I know even less about, and what factors influence it. . .

Quote from: http://en.wikipedia.org/wiki/VenusVenus[/url] might look like, were it to have a livable atmosphere, faster rotation speed and of course, life. I suggest reading the wikipedia article as it goes over the magnetic field, lack of tectonic plates, etc...

For protecting the planet from cosmic radiation, I think that the "mystic properties" of the rings will take care of that bit, to enhance the otherwise weak magnetic field that this planet will have.

Ok well Venus has a liquid core. However, yes it has no tectonics. I didn't realize that lack of tectonics would disrupt a magnetic field (you learn something every day). Anyhow I might suggest giving your rings a highly magnetic property (or barring that perhaps there is something buried at the center of the world, perhaps an artifact). Whatever it is, it drives off the dangers of open space.

Anyhow we are moving into the realm of over-realism here. Players probably won't care that the rings above are a shield against the radiation of their star. At most they might passingly notice this when a worshiper of the rings (and trust me... something like that is going to have alot of worshipers) tells them so. Even then they will probably just go "oh that's interesting" and continue on. Just focus on the things that will have a usable impact (and that you don't want to just explain away with magic).

Nomadic - you made the suggestion I was about to put forward as well - the rings can be used to explain a number of things which are otherwise inconsistent with natural science. Venus illustrates a number of things I was saying about atmosphere - providing the rings with various counterbalancing properties then offers a neat and elegant solution to most if not all - some physical - magnetic field, and where it doesn't inherently, magic can make up the balance. At that point I think verisimilitude would be maintained nicely - the only thing that really *needs* to be done is provide a rational for the things which would strike players as immediately incongruous. If players look at some facet of the planet and immediately think "wait - that wouldn't work like that" and the creator can say, "you're right, but the rings do such-and-such instead" then the players respond "oh, cool, okay that makes sense," and role (sic) on with it. . .

The biggest thing to address at the fundamental realism level is the tectonics - Venus doesn't display them because of the physical structure of it's surface - an Earhtlike crust with oceans, etc. would have Earthlike plate tectonics - this one would pretty much have to be subsumed in some sort of semi-magical "stabilizing" effect/field produced by the rings. It doesn't really need more than a simple statement that the rings prevent plate movement - the only real reason to take them into effect at all is when you're creating the initial planetary geography - normally they present the reason mountains and volcanic activity etc. appear where they do (as we discussed regarding those elements in UR). After that it really becomes irrelevant since they're effectively "set in stone" - any changes occur over such a long geological time scale that they effectively don't even exist from the perspective of the inhabitants. Hence, even when present they don't need to be significantly detailed - "here's the mountain, here's the volcanoes: there are plates in this region pushing against each other or pulling apart," and the matter can be left at that.

Without them, I would personally try to provide some rational for why those geological features exist, but that's really a matter of my own comfort level - I like things to have at least a rudimentary explanation (as a lot of my setting writing displays,) not everyone (gm or player) feels this needs to be nearly so in depth/detailed and I realize that I tend to provide more in Panisadore than is strictly necessary for good gaming in the setting and most players would never really even be aware of a lot of it. . . I just feel that I'm more consistent in creating what the players *do* see if I have that underlying stuff worked out in my own mind and writing it out is a necessary part of the process for me in getting it worked out - and remembering it later. I don't really recommend others take things so far unless they're trying to accomplish the same thing (as part of a similar creative process) for themselves. Their players won't need it.  

Quote from: Snargash Moonclaw...When you say "the dynamo has reversed itself" are you only remarking on the polarity - or reversing the actual direction of spin (which would explain why the polarity reverses) within the core? I'm particularly curious about that - one of the more well known/published New Age prognosticators, who is a geologist, asserts that the earth itself is slowing in rotatation and will eventually stop momentarily and then actually start spinning in the opposite direction (and claims it has done so in the past). I find this a bit harder to swallow, but hesitate to say it's impossible - not sure of the physics involved to be absolutely certain - on the other hand, the motion of the core is something I know even less about, and what factors influence it. . .

Well, magnetodynamics is tremendously complicated, and not really my strong point. But this page (http://www.geomag.bgs.ac.uk/reversals.html) on magnetic reversals is pretty decent. In short: We are seeing a diminution of the magnetic field over the last century that could indicate the beginning of a reversal. Computer simulations show that this is possible, but also that it is common for the magnetic dipole to weaken, almost to zero even, without an actual reversal.

The process has to do with liquid motion near the core/mantle boundary which is not related to the overall rotation of the earth. Conservation of angular momentum would forbid the reversal of the Earth's spin without some strong interaction with some external object, so that's right out.

Fascinating article there snakefing. It also makes me realize that we can probably get away without a magnetic field. As the planet in question has a much thicker atmosphere than earth's it stands to reason that it is capable of blocking more stellar radiation. Certainly not all of it but I could see it (combined with the shielding rings) as being enough to allow life to thrive safely on the planet.

@Snargash Moonclaw
I think you hit the nail on the head with that last post.

I've got lots of ideas now, and will need to spend some more time putting them all together. If anybody has any other suggestions though, I'm all ears.


*edit*
Okay, I just had an interesting idea. Would it be possible to have a form of algae that floats in the air? Photosynthesis requires Light, C02 and H20. There will be an abundance of C02 in the air, and there should be a lot of water moisture, especially later in the afternoon when the water has been evaporating a lot. I can picture there being large clouds of floating algae being pushed around the globe just ahead of the dusk storms.

It would be interesting if I could move a lot of the life that exists in the oceans of earth up into the sky. Like the aeria that stargate mentioned in my Dragon thread (basically sky whales).

You could do that yes. In reality it would require a bit of a redesign of algae structure but it could happen. This is made more true by the thicker atmosphere.

Speaking of algae, the page on coral you linked to re: coral bleaching due to temp. fluctuation contains a link going into this particular phenomenon in greater depth and detail (http://en.wikipedia.org/wiki/Coral_bleaching). While this can actually result from a number of different factors besides temperature elevation, they are all very easily and elegantly adjusted for.

[blockquote[wikipedia page linked above]The corals that form the structure of the great reef ecosystems of tropical seas depend on a symbiotic relationship with photosynthesizing unicellular algae called zooxanthellae that live within their tissues. Zooxanthellae give coral its particular coloration, depending on the clade living within the coral. Under stress, corals may expel their zooxantheallae, which leads to a lighter or completely white appearance, hence the term "bleached". [/blockquote]

The two most prominent causes are the combination of temperature and solar radiation increases during summer. Seasonal changes are already eliminated and solar radiation mediated as causes. Beyond this all you need to do is simply provide your world with algae that has evolved to be more helpful (or at least not contribute additional strain) to the coral organism when it experiences the stressors. This even supports verisimilitude since different environmental conditions from Earth's will of course produce different evolutionary adaptations - and since you are reducing the instance and importance of photosynthesis in planetary ecology, it's already a given that the algea have evolved differently. Also of course, the coral itself may have evolved to be less vulnerable to these stressors. . .

On other notes - if the planet is under constant, heavy, universal cloud cover like Venus, then that will produce your albedo (coloration from unusual elements suspended in the clouds can vary how much light is reflected and how much absorbed by the clouds). Without such cloud cover, albedo will be similar to Earth's since the primary reflective surface is water roughly 2/3 in both cases. As with clouds, coloration from "non-Earth-standard" chemical constituents can produce further variation as desired.

Cloud forests would be quite common - I suspect prevalent even, since heavier atmospheric elements will produce low-level atmospheric condensation as dew point is approached. The hydro-atmospheric exchange system/cycle will be close to Earth's given similar proportion of water coverage as discussed above.

Mycorrhiza make some sense, however the carbs they get from the host plant are the product of photosynthesis - you will need an alternative. Grassy savannas are likewise sensible - open canopy woodland still fits that description so your broadleaves can coexist. Consider especially the baobab (http://en.wikipedia.org/wiki/Baobab) tree. Floral/fungal symbiosis would probably be a nearly universal day/night adaptation - each species of one being pretty specific to a single species of the other.

Cold blooded animals (like dinosaurs) would actually simply hibernate (http://en.wikipedia.org/wiki/Hibernationl) rather than die, hibernation being a much more prevalent adaption among them than warm-blooded animals (few of which truly hibernate, all of them relatively small). Many cold-blooded animals go into hibernation (or some similar metabolic suspension) due to other climate extremes than temperature -like  desert reptiles and amphibians burrowing between rains. Day and night environments would ultimately be very different with (as you said) few organisms (animal or plant) active during both, although twilight could be extremely interesting, with day and night hunters in a near feeding frenzy either to prepare for dormancy or to recover from it. Really, any sort of animal could be introduced as active during either period - simply being adapted to be active in that temperature range and dormant in temps above or below their comfort zone. (Some in fact might only be active at twilight - when the most food is running/flying around. . .) And, oh yeah, I definately see dragons as lovin' this place! Most likely the dominant life form and hunting primarily at twilight (though capable of activity at any point - just lazy. . .)

Symbiosis - cool - there's good reason as outlined above for this to be a prevalent evolutionary survival mechanism manifesting in a broad spectrum of adaptations - including sentience/intelligence. It could even be what produces sentience and intelligence - such as all sentient life being developments of non-sentient host forms (related to or even being other common flora and fauna) linked to intelligent but physically frail symbiotic organisms. Coral and trees could even display such sentience (the former probably displaying a sort of hive/colonial unified mind). If you were to look at it in this fashion then you really only need to develop a single genus of sentient life forms - manifesting in different species adapted to different familia of hosts - dragons being produced by the species adapted to certain dinosaurs. . . THis could get extremely interesting to play! Character creation then becomes a process of choosing first the intelligent symbiote followed by selecting the host species from the family the symbiote is adapted to. This would give a whole new meaning to concepts common in other setting such as "Dragonfly Clan," "Wolf Clan," "Mantis, Dragon, Serpent, Eagle. . . Clans" Clans, Tribes and Nations (in the manner of Native American usage of such terms) could develop either segregated or integrated - tribes preferring the presence of many different clans which are elements of a larger "nation" defined by biological order or family, e.g., Raptor Nation demonstrates a strong unifying commonality, however, Hawk, Eagle and Owl Clans still manifest distinctly different medicines which individuals of these clans bring/offer to their tribes. Forms/lines of segregation and integration could occur as well - certain predators for instance would not be found in tribes which contain clan members linked to their preferred prey - e.g., many clans of the Raptor Nation would not be found in tribes incorporating members of Rabbit Clan, however, Kestrel and some other clans of that nation may be. Clans which normally compete for specific food sources might likewise segregate, although they could also cooperate when given sentience. Other dominance/hierarchy patterns would likely manifest - Dragon Clan being the obvious starting point of reference from which to consider that. Of course, all of the above refer to terrestrial fauna, analogues of which might exist alongside of uniquely alien creatures native to the planet - you've really got free rein in this regard. Marsupial-like analogues could occur even among cold-blooded chordata (some snakes do birth live young rather than laying eggs after all) which might give rise to such a symbiosis.