Talitheria is lighted by the Green Gem and by the Amethyst Fire that orbit the hollow world at lunar distances and at one half of one Astronomical Unit, respectively. Each gem is five hundred miles in diameter, and sheds light on the planet below, and into the great crevasses in which the Shadowthings breed.
Light has a strange quality here, almost touchable, and the shadows are heavy, and the light is green, or purple, or some combination of them both. Honest yellow sunlight and bright blue skies do not exist. The sky is dim, and so is the world to human eyes. The locals are humanoid, and have excellent low light vision.
The interior of Talitheria is a place of great darkness where malicious things that cannot stand any light live. But some of their half-breed children can venture up out of the Great Crevasses into the light when it is most dim. The residents of the surface, the Halfworld, bar their doors on these no moon nights, or on nights in winter when the gems are not visible for the clouds.
Such things as live in the dark are the great Charcoal Dragons, wise and malicious and hungering, but the merest touch of gemlight is enough to turn them to ash.
There are two prominent forms of magic used by the Halfworlders. Each relies on the light of its favored gem.
The Purple Magi bind magic to ritual, and to staves, and find mana in things touched by the dawnlight of the purple gem, and not polluted by the green gem.
The Green Men are willworkers who if standing in the light of their gem may work magic by will and the word.
Great and changing alliances were formed, and then ripped asunder. Kings tried to master these magicians through history with Green Towers and Purple Havens, and the long distant Emperor of the Gold was able to force both Green and Purple to live together in harmony by means of hanging those who disagreed with his royal edicts and burning their towers and havens.
In the time of the Emperor, great advances were made on creating mirrored towers that would reflect the light of the gems down into the crevasses to protect the people, and even to make possible an eventual invasion and war of extermination. But one of the mage traditions chose treachery and alliance with the Darkness rather than peaceful coexistence. To hear both tell the tale, it was the other that was guilty.
However, most serious historians who also have extremem bravery or means of anonymity agree that it was the Green Men who betrayed humanity. However for a sage to say this in public is to sign his own death warrant as Green assassins are likely to find him.
After the Emperor, there were successor states, but neither tradition ever allowed a king to get that powerful again. There were wars as coalitions of Green countries warred on coalitions of Purple countries. And there were times when the Purple or the Green gave over a country to its opposing tradition in order for a restive king to be punished and brought low.
But finally, a thousand years had passed, and the Purple Magi succeeded in casting a great spell that cost the life of their greatest arch-magi. They put out the Green Fire. Suddenly, no Green Man could cast a spell.
This had the effect of reducing the light hitting the world which hurt crops. It also made a number of settlements unviable as they had required the Green Light to hold back the shadowthings from a nearby crevasse.
The Coalition of the Purple rode forth, and smashed the armies of the Green that still existed, and a few towns that revolted and hid behind their walls were reduced to smoking rubble. But the year long campaign served its purpose. All of the Halfworld was united at the Council of Purple. The Twenty Nations were joined, and the Purple Emperor was crowned.
Meanwhile, the shadowthings had advanced and grown bold. Crops were having difficulty. However, without the constant harrassment and expenditure of a war, and due to new trade routes opening up, the Emperor was able to stave off starvation, get newer low light crops planted, and drive back the Shadowthings into the great crevasses.
Decades passed, and the world stabilized. Much of the power was divided between the Purple Havens, the permanent bueraucracy, and the Emperor's Men. It was not a very good system, but it was markedly better than what had gone before. The Purple Empire was becoming a prosperous nation, and children in the cities learned their loyalty to the Emperor first rather than loyalty to the individual nation they came from.
But Fifty Years to the day, the Green Gem flared to life again.
Most people rather liked the rule of the Emperor. Some did not.
The Purple Havens are faced with a problem. In order to restrain a rogue purple mage, a criminal, all one had to do was to take away their stave and their mana filled bits and pieces, and shut a cell door in their face.
But the Green Men are not so easily disarmed. They are creating armies, funding bandits, and striking in the night at the weak ones. A soldier might stay on the wall of his city for the night only to come home in the morning to find his wife strangled in her bed by vines.
Some of the Purple wish to try to appease the Green, to grant them some rights, although not equal status. Others note the rumors of the Green Men consorting with the Shadowthings, and the few historians brave enough to say the truth, and lucky enough to dodge Green assassins remind the people of Green treachery. And they note that the only way to really stop a Green Man is to kill him. You can't after all chain a man in complete darkness for if you do, he becomes a Shadowthing. And if a Green Man has the green light, he can cast magic.
A number of the Purple might be somewhat sympathetic to the outraged cries of the Green, but they point to history, and they point to pragamatism. The world is objectively better off they claim now that their is an Emperor again. Its a hard claim to refute.
The Green Men insist on their rights, and their vengeance.
This world is a confused mess. There are Purple Magi who are good and decent and wise, and then there are Purple Magi who are homicidal racists, and sometimes both members of the Purple Magi favor the same policy.
There are Green Men who are eager to help out the oppressed, second class citizens and restore Towers and not cause unneeded problems even if they do feel bitterness, and then there are other Green Men who are bargainning with the Shadowthings. Some of the great think that is how the Green Gem was relit...Shadowmagic.
"Color" is a very tricky thing. Human eyes see 1) brightness across a wide spectrum and 2) three narrower bands of that spectrum. Those three bands we call red, green, and blue.
The "cones", the sensors that pick up these colors, are each attuned to one of the three bands, a bit like the pixels in a color television or color dots in an LCD screen. They are sensitive in a bell curve, responding most strongly to that frequency at the center of their range and gradually less sensitive as the frequency shifts. If a light hits your eyes that is actually green, in that it is the frequency at the center of the green sensor range, your brain sees it as "green".
Now it gets tricky. If a yellow light hits your eyes--that is, one which is of a frequency half way between red and green--three kinds of sensors respond. The "rods" which determine brightness recognize that there is light. The green cones respond some and the red cones respond some, because that yellow light is toward the edges of their respective ranges of sensitivity. Your brain thus envisions the color "yellow" as its interpretation of a frequency of light which is half way between green and red.
It gets trickier, though. Suppose you have a fully reflective diffusive surface--a white wall. If you were to shine a yellow light on this wall, it would be perceived by your brain as yellow, because it stimulates the red and green sensors equally. However, if you shine one purely red light and one purely green light at the same spot on the wall, your eye will be hit with the reflection of two colors, one red and one green, in equal amounts, and thus the red and green sensors will be equally stimulated. Your brain can't tell the difference between equal stimulation that comes from light of two frequencies and equal stimulation from light of one frequency between them, so you again see "yellow" light, even though there is no light of a yellow frequency present.
If I understand "purple" correctly, it is of a frequency on the opposite side of the center point of "blue" from "green". Thus the rods detect the presence of a significant amount of light which stimulates only the blue cones only partially. The brain then says that since that light is not stimulating the green cones but is brighter than the blue cones are perceiving, it must be of a higher frequency than blue, and it interprets that as purple.
Assuming your two light sources provide light in the pure green and pure purple frequency ranges, when both shine together your light will vary from a slightly bluish green through a strong blue to a slightly bluish violet, depending on the relative intensity of the two light sources. Of course, it will be more complicated and confusing perceptually, because the two light sources come from different directions, and thus the shadows of each are the color realms of the other--wherever the purple light is shadowed, the green light dominates.
The indigs will not have cones for red light, because there is none in their world. (Purple is created in our brains by the combination of red and blue light because the green receptors are dormant and the increased brightness on the rods but not on the blue cones shifts the interpreted spectrum higher rather than lower, until the red rises to levels that dominate. Pure purple light is not a combination of red and blue, but a higher frequency than blue, where red is the lowest frequency range of visible light.) You might need to give some consideration to how their brains interpret the light they perceive, but probably if their light sources are putting out very narrow green and very narrow purple bands of light the cones in their eyes will match these ranges, and they won't see "color" in the sense we do, but discrete overlaid images of purple versus green. What is more interesting is what the visitor sees, and that's what your referee is going to have to understand and describe--but he's also going to have to understand that the indigs don't see anything at all like that.
*****
The other point that probably should be addressed is the revolution cycle of the two light sources. I'm assuming that these are extremely fast--we don't have the green light in the sky for fourteen days and then gone for fourteen days, and the purple light in the sky for half a year and then gone for half a year. At the same time, it's evident that they are not on the same cycle, because sometimes they are in the sky simultaneously and sometimes only one is. It's possible that you've got them at relatively fixed positions--if they are ninety degrees from each other, one rises, six hours later the second rises, six hours later the first sets, six hours later the second sets, and then there are six hours of darkness. However, I suspect you're looking for something much more interesting, such as the green is on a twenty hour cycle and the purple on a thirty hour cycle, giving you:
- 0:00 Green rises, Purple rises
- 5:00 Green 1/2, Purple 1/3
- 10:00 Green sets, Purple 2/3
- 15:00 Green absent, Purple sets
- 20:00 Green rises, Purple absent
- 25:00 Green 1/2, Purple absent
- 30:00 Green sets, Purple rises
- 35:00 Green absent, Purple 1/3
- 40:00 Green rises, Purple 2/3
- 45:00 Green 1/2, Purple sets
- 50:00 Green sets, Purple absent
- 55:00 Green absent, Purple absent
- 60:00 Cycle restarts at 0
Anyway, that's an example. You can get much less consistent relationships by using mathematically unrelated numbers. Because the ratio here is 3/2 the cycles come together frequently,, every sixty hours, but a combination of 19 and 29, both prime, would mean they rise together every 551 hours. (The quick way is to reduce both numbers to prime factors, then find the least common multiple by eliminating one of any factor common to both. That is, if you have a six hour cycle and a fifteen hour cycle, the six hour cycle is 2x3 and the nine hour is 5x3, so they'll align every 2x3x5=30 hours, the extra factor of three discarded.)
Hope that helps.
--M. J. Young
Woah. wow. I'm telling ya' MJ, this type of thing is what you need in your novels.
Ringworld earned a lot of respect (and some derision among engineering students but in this case, that might be a good thing) by the idea of a wedding band around a sun. Have your hero figure out this kind of stuff as he visits a new world, and you're going to find a certain type of SF reader is very impressed, and others who won't entirely get it will still like it.
This applies also to your description of phonemes. Its that 'jewel' idea I was going on about before. There are a lot of readers that like short explanations of interesting ideas. And this type of thing can be the problem definer in a story as the Sherlock Holmsian hero explains that the symptoms that everyone is upset about are merely the symptoms, and that the cause is (Insert jewel), and that the solution is therefore...
There are stories which are essentially puzzles. Hero in a shuttle crashlands on alien planet. Aliens are acting weird and dangerous. Hero uses odd little bits of fact to build up brilliant and out of the box theory. I imagine it would be possible to make a story hinging on the fact that the human spaceman and the alien indig saw something different under the lights of the Green and Purple Moons.
If you had Laura?? the Sorceress Verser arrive on her Paradise Island and have something like this as the background which she had to figure out in addition to the rest, it might work as an intellectual puzzle to add interest to that world. (As one SF writer put it, he found that SF readers paid for ideas, and if he instead of just putting one idea in a story, he put two, they liked it.)
Now, I'm going to have reread this at least twice because I'm lazy, and my brain is only 1@9.
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The more obvious pattern for gemrise is higly reccomended unless you have a player who is 1)very smart indeed. 2) Adores puzzles. In a SF novel, definitely go with the more obvious pattern.
I'm trying to think if the indigs saw a narrow band of green, and the verser was wearing a yellow shirt...it comes back as Black? Not there? White?
It would probably be what we would consider 'red', seeing as it is on the higher-frequency, lower-wavelength end of what they can see normally.
Knowing what the indigs see is tricky, because it depends on how you define indig vision. Our vision is broad-spectrum because our "yellow" star emits radiation over a very wide spectrum--technically, at multiple points within the spectrum. The colors of the rainbow are a primitive version of a spectroscope, dividing the light into all the individual frequencies of which it is comprised, but there are actually gaps in the color flow.
If the light sources put out pure single-frequency light then there's no reason for the indigs to see anything other than those two frequencies. They either combine the two frequencies or keep them discrete. If they see color, then it is most likely that what you are calling green they see as red and what you are calling purple they see as purple, and they see the full range of colors between based on the relative amount of green versus purple light reflected from them. However, since it's a two-frequency system, things in this world would never be described as being a particular color, because the apparent color (in the eyes of the indigs) would change according to the available light. It is equally possible that indigs see green where green is reflected, purple where purple is reflected, black where no light is reflected, and white where both are reflected. The balance between purple and green might be expressed in shades of gray or tints--if you're using an RGB color generator for your computer (most art programs have them) you might get the effect by tying the red value to the blue and running the balance between the RB and the G to see what colors are produced. All three equal will be gray, and as the balance tips you'll see an increasing hue of one or the other of your two colors.
But that doesn't really answer the question, because you asked what color the yellow shirt appears to the indigs, and the answer is that we can't know based on that information. Why is the shirt yellow to us? We confuse pigment values with light values all the time (one reason why CMYK printer colors and RGB monitor colors are often different) If the shirt is yellow because it reflects only light of a yellow frequency, then it's going to look black to the indigs because they can't see that frequency at all. However, that's almost certainly not the case. If the shirt reflects equal parts green and red light, then the shirt will look green, the indigs unable to see the red ligth at all. But that's probably still an oversimplification.
Leaves are green in the summer; in the autumn they change color. The reason they are green is that they are filled with chlorophyll, which dominates their color, reflecting only some of the light in the middle of the visible spectrum, the green light. The darker the leaf, the more efficient it is at using the light that strikes it. Bright leaves are reflecting more of the green, but still absorbing the reds and blues and other colors. But when autumn comes, why do the leaves change? The tree stops maintaining the chlorophyll, but there are other chemicals present which reflect the red and yellow and orange and blue and purple spectrum lights. The fact is, they have always been there and they have always reflected some of that light; but the chlorophyll has dominated, absorbing much of that other light, such that the balance of the reflected light has been almost entirely green. If we could not see green light at all, then probably we would see some of the colors that become visible when the green light is gone (although the chlorophyll is still absorbing much of that light, so the leaves will be very dark).
So the "yellow" shirt might be reflecting enough of the green or purple light to have a color completely unpredictable to someone who sees with our vision.
In all of this we must be mindful that the colors to which we give names are our minds' interpretations of the signals received, and not actually the reality. My piece on Infravision, Ultravision, and Physiology goes into this a bit, talking about how someone who sees heat or ultraviolet light as a primary color would see a completely different range of colors, probably seeing objects as having entirely different colors from each other that look the same to us. We know that birds and some insects perceive color because their visual receptors respond to narrow bands of frequencies as ours do, but we also know that their ranges of visible light are different from ours so even if they see the same colors in their minds, they see them for different reflected light values--and we have no way of knowing what they perceive in their minds.
So the simplest solution is to assume that your indigs see only the two colors, what you call green and purple, very narrowly, and that their minds create intervening shades based on how much of each they perceive. Their eyes have no rods, because the ambient light is only pure green and pure purple, so those are the only colors of light actually reflected. They see white when all the green and purple are reflected together, black when neither green nor purple are reflected, and other shades as discussed. The yellow shirt appears whatever color it would based on how much of those two frequencies of light it reflects. On that point, most objects reflect light broadly across the full visible (and part of the invisible) spectrum; they have to, or they would get very hot from absorbing all that photonic energy. A very bright yellow shirt is probably reflecting a lot of light of every color dominated by the bands which cause us to see yellow (read the RGB numbers on a yellow image for an example), so it would appear probably on the green side of gray. But an object whose color comes from a very narrowly defined frequency of light--say a red or blue laser--would be black (the lights themselves being invisible) because it has no light of the specified frequency.
--M. J. Young
...and the horse said....
(That's part of the punchline of a joke, but if you don't know it you'll have to ask.)
--M. J. Young
Well, it might not be as simple as that. After all, there are presumably other stars, and when both gems set, they'll still be providing some light. It's an open question as to the specific color of the stars, but whatever it is the indigs can probably see their light as well.
How are the indigs set up in terms of available things that burn? And, more importantly, does the emissions spectra of those things include purple, green, or both? I'd presume that they don't have vast quantities or firelight doesn't harm shadowthings, because otherwise it seems like the golden emperor would have assembled an army armed with torches and supported by purple wizards instead of building elaborate mirror towers, and wiped out the shadowthings.
So, are the purple mages trying to repeat the great spell, then find a way to destroy the gem utterly? Seems to me to be a reasonable plan on their part.
Reformation era tech so LOTs of stuff to burn. Hmm, it would have to be a differing tech or a magic to be other than normal, so I'd say wood burns as normal. But the indigs can't see the other aspects of its light.
????
Right. You'd have to say that the Gems exert a magical influence (MJ talked about this in the 'Vampires' tag about the authority of the Sun over vampires.)
The Golden Emperor was supported by Green AND Purple.
That seems a reasonable plan for some Purple Mages to undertake.
I asked about the emissions spectra partially because I was applying too much science to the magic, which is somthing I kinda got from shadowrun.
Also, I only mentioned purple because green mages would be powerless underground.
I suppose I too was applying a bit too much science; but let's consider the possibilities.
- Vision evolved to take advantage of the available radiant energy. Since we have two lights of significant brilliance in very narrow bands, that vision would almost certainly use those two bands, almost exclusively. Thus other light sources would only provide illumination to the degree that they included those colors--there is no particular evolutionary need to see the stars, and fire light is inherently temporary and artificial in this sense, not something under which creatures would evolve. Thus either such other lights provide illumination to the degree that they radiate within the visible spectra, or they do not. Many celestial objects radiate photons at frequencies we do not see, because their level of illumination is insignificant relative to the visible spectrum light we do so, and thus it is unreasonable to expect vision to evolve which utilizes light in frequencies not ordinarily occurring. Vision of light other than those two frequencies is unlikely, unless the light-sensitive cells responded to all electromagnetic energy between the two specific frequencies because it was a simpler evolutionary outcome--in which case color vision would be non-existent, and our mages would not speak of the colors of the light, but only of the stars by some other characteristic (such as speed of movement across the sky).
- Creatures designed to exist in a world in which the light was almost exclusively of two colors would be most efficiently designed if their vision made effective use of the light at those two colors. There would be no logic to designing vision for such creatures which perceived light outside the primary available bands, unless the designer perceived a value in providing visual capability such as anticipating the eventual use of artificial light sources. In this case, color vision could exist along with an intermediate visual sensitivity, probably by a sensitivity something like cones with overlapping fields, which would not be active until other light sources were discovered.
--M. J. Young
Heh. I like the alt-universe ID arguement. Save this jewel in your jewel box, and haul it out when you need it in a story.
Actually, the most critical component of what colors they can see is probably the color of the stars other than the gems, since night is an especially important time for them to be able to see well. They'll likely be able to see very well in those frequencies, and probably also in the frequencies produced by fire. However, since fire is probably a recent development, evolutionarily speaking, that's not nearly as certain.
That assumes that there is sufficient illumination from the starlight to be worth the adaptation to see by it. A diurnal creature might simply recognize that darkness was approaching and find as save a place to sleep as it could, then wait for light to return.
That is particularly likely given the nature of this world, in which the periods of darkness are usually relatively short (because the other star will rise soon, most of the time).
Of course, there is an inherent absurdity, in that we are assuming that the stars in question produce light exclusively at their stated frequencies, such that an evolutionary development which perceived light adjacent to those frequencies would be worthless. No natural star would be that limited in its frequency output. Thus we are working already in an entirely theoretical model, and it's difficult to guess at outcomes. Certainly if there are nocturnal creatures in this world, they will have developed eyesight that utilizes a much broader range of the EM spectrum, as well as having much larger pupils to gather it. Absent a moon, however, I find it unlikely that diurnal creatures would adapt to the extremely low light levels of the stars, unless they are considerably brighter than our own.
But it's an interesting question. We've assumed to this point that there are stars, and that such stars are not limited to the two colors of the primaries. Given Eric's initial descriptions, it might be that there are no such stars (and thus that the periods of darkness are illumined only to the degree that atmospheric dust scatters the light from the other side of the world). It might be that all stars are one of those two colors, but it seems somehow improbable--not that all the stars would be of those two colors, but that if there were many such stars the green wizards could block all the red light. On the other hand, if there are such faint colored stars, it might be that very weak magic is still possible in the dark periods.
Just musing.
--M. J. Young
--M. J. Young
I'd say all the stars are gems, and each has its own color, and so some other sources of green and purple are available which means very weak magic is possible.
wow, nice work guys!