The Cycle of Cyann IV

About one year ago I first wrote about the Cycle of Cyann (here, here and here). This is a French series of graphic novel about a young woman travelling through worlds and time using an ancient portal system. It is definitely a series for those with patience, as the series started in the magazine "À Suivre" in March 1993, and now there are still only four albums. Unfortunately, there still does not seem to be a version in English. In the course of the story told in the first two albums a party searching for the cure of a dangerous disease travel to the planet Ilo. After getting down they have to make their way across a continent, encountering a variety of climates and biotopes as they go along. At one point, the party travels through a wintery place. The image is taken from a Dutch version, so now you know that what they are saying is largely not an alien language. The party is travelling in an enormous vehicle, here shown in the background. The characters discuss the 'funny animals' in the foreground, called 'ziglones'. The following images shows how the ziglones huddle together, no doubt to conserve heat. Mind you, the ziglones play no part in the story. They are just there to make the background, the world of Ilo, more interesting. It works for me...

Click to enlarge; copyright Casterman

Shortly afterwards the protagonists spot the vehicle they are following and wish to catch up with make a detour around a small valley. With the commander (Cyann) in bed, the crew charged with steering their enormous vehicle decides to cut some corners and head straight through the valley, dotted with snow-covered domes. The following page shows what happens when the vehicle crashes into the domes.

Click to enlarge; copyright Casterman

Some of you may be distracted by the appearance of Cyann on the command post. The home planet of these people is hot and humid, and they dress accordingly. Something that may also play a role is that the French regard such matters in a rather more relaxed manner than people in some other countries do. Vive la différence... Anyway, those not distracted or post-distraction will notice that the domes are filled with animals, called 'albarans'. The crew protests that they could not know that the domes were hollow and do not allow travel, but Cyann says that she did know. Knowing details about the planet and its dangers is a recurring theme throughout the book, along with how some people have knowledge they were not supposed to have. But back to the domes. The crew still thinks the albarans are kind of cute, but the lesson that is is better to be careful in an ecosystem foreign to you is rammed home by what happens next:

Click to enlarge; copyright Casterman

And that is all we ever get to see of the albarans in the story. A considerable amount of work must have gone into the design of these ecosystems. Luckily, there is an accompanying book that offers a glimpse of all the work the authors (François Bourgeon and Claude Lacroix). That one (La clé des confins) hasn't been published in English either, nor in any language other than French as far as I know. The book contains more information on the universe of Cyann. There is a double page on the albaran dome system. Not wishing to ruin my copy, I left a grey band running through the page. Basically, the dome is the result of a collaboration between a plant and a fungus, creating a home for albarans, 'lagades' (a species of bird, shown on the right), insects and even fish.

Click to enlarge; copyright Casterman

As you can see, the drawing is dotted with little asides describing elements of life in the dome. Still, much is left unsaid, such as how the dome generates enough heat to prevent freezing, or how this complex system evolved. But perhaps that would be asking too much: I can understand that the authors wish to show some details, but not all. Few things get boring quicker than an over-abundance of explanations; always leave enough unsaid to keep the reader hungry for more.

Cyann and Ilo's rings

The last time I introduced 'Le Cycle de Cyann', focusing on the wildlife. On browsing through 'La clé des confins' my attention was drawn to some astronomical explanations. In the second album of the series Cyann travels over the planet Ilo (there should really be a dot in the letter O, but I cannot reproduce that here). That planet is of interest as it has a very long and narrow continent winding almost like a snake over the globe. This provides an opportunity for Cyann to travel through a vast array of landscapes along with their accompanying biotopes, much to the enjoyment of the reader.

But there is another thing that struck me, and that is that Ilo has rings. I cannot say whether it is at all probable that an Earth-like planet has rings, but their presence certainly has some interesting consequences. From seeing photographs of Saturn, everyone knows that the rings cast a shadow on the planet. But that shadow will not always fall in the same area, provided the planet is tilted to a degree.

In midwinter the North pole is tilted maximally towards the sun, and so will the rings; hence they cast a large shadow on the southern hemisphere. But at the spring and autumn equinoxes the plane of the rings present to the sun edge on, so the rings cast a shadow on the planet no wider than the rings themselves. Here is one picture of Cyann, waiting for her lover on the equator, on the day of the equinox:

Click to enlarge

She is facing the sun, and the rings behind her are lit, forming a luminescent vertical stripe in the sky. Looking in the other direction the rings form a dark stripe. Looks like an excellent setting for a romantic encounter.

The consequences of all this tilting are fairly complex. Think of how the ring shadows complicate winter: the shadow of the rings falls on the hemisphere that is tilted away from the sun, where it is winter anyway. But the shadows make the winter days even darker, but in complex ways: it is theoretically possible for the sun to come up, disappear behind the rings, come back again in midday, disappear behind the rings again, and finally to come back only to set on the horizon. All such matters are brilliantly handled in the book. Here are two pictures from 'Le clé des confins' showing how it works. One is an equinox picture, and the other is a solstice picture. If you need more explanations on why the sadows change shape, please go to the planet page on the Furaha site.

Click to enlarge

These caught my attention as they resemble the images on the astronomy page of Furaha quite closely, in particular the way the terminator is drawn. The 2x1 ratio of the maps is a giveaway that there is some serious thought here. So I wondered whether I could copy all these ring effects, and sat down to some good old-fashioned Matlab programming. Here is how that started:

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You will see rays of the sun -the blue lines- starting from the edges of the rings. They are of course all parallel, and strike the planet (many don't of course, and these are not shown). The relative sizes of the planet and rings were taken from the book, and I estimated axial tilt to be 21 degrees. Once the x,y,z-coordinates of the rays falling on the planet are known, which only takes high school mathematics, these can be converted to latitudes and longitudes, et voilà. Project these over a rough map of the planet, redrawn from the book, and there we are:

Click to enlarge

Nice, isn't it? It is quite close to the drawing in the book, but small changes in ring diameter and axial tilt have large consequences. I also found that ths shape of the terminator in the solstice picture in the book is not exactly right. I can only assume it is some copying error, because the rest is much too good to be guesswork. Do not underestimate the amount of thought that has gone into this. I know from experience that working out the form of the terminator can take quite a bit of effort. Bourgeon and Lacroix not only did that too, but also worked out correct ring shadows, as well as thinking up cultures, animals, etc. It's almost enough to make you desperate...

But I won't be! Instead, I think I will produce some animations of the shadows as they change in the course of a year. Later.