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OOC: nice job! I did years ago a sky with star, sun and 2 moons with Blender, so I think it is possible today to make a "realistic" sky. Can somebody expose the idea to the team of Ryzom?

[ooc]
Personally I wouldn't mind if the rest of the sky became more "realistic", but I'd really like to keep the fixed "sun" (collection of fixed suns). I like the flaring and calming of the object, and the fact that it is obviously artificial (since the seasons must be due to programmed increases and decreases of the total output of the sun.) I think it adds an element of the exotic and inexplicable to the environment.
[/ooc]

It is a game- so I don't expect it to be 100% accurate, but the origin of this discussion was to possibly learn or infer more about Atys or other Ryzom things.

Because we obviously have an artificial light instead of a sun I would propose a couple ideas:

1. Atys does not orbit a star, the star does not emit sufficient usable light, or the orbit of Atys is very far from the star of this system.

2. Assuming that the artificial light is a technological structure (most likely in this case) it suggests the Karavan/MegaCorp have access to fusion. Its the only energy source in our current understanding of physics that would be able to produce energy comparable to a stars' power- because it is actually where star get their power from. But if they have fusion, why the heck did they bother with Atys? They could just take materials from Atys or the ringed planet or the orange moon and create a giant rotating habitat or floating city on the ringed world.

Yes, most of this is OOC. I am RP friendly but this is not solely a RP thread :)

Third possibility, Atys orbits a star but is tidally locked and we are not on the side facing the star. (This would mean that any "realistic" Stars would have a motion that was linked to the year, not to a day.
We might even be in a Trojan position defined by the ringed object and the star.

You are *assuming* that the sun is technological. It might also be magical. Even if it is technological, placed there by the Karavan, and based on fusion, that does not imply easy transmutation of the elements. Remember, we don't really know the Karavan's agenda, and we only have the word of the Kami that the Karavan are here to strip-mine Atys.

By the way, we know that when we look at what is apparently a solid object in the sky (at night after the flares die down) we see something that looks about like the Moon does in the skies of Earth. If we assume an angular diameter of 0.5 degrees (Moon from Earth), and a distance of 250km (midway in my estimates), the diameter of the physical object is only 2 kilometers! That's not nearly big enough to support fusion, though it might be big enough to be a radiator for a fusion reactor. Note that it is also *much* smaller than Atys, which extends at least 35 km without significant deviation from planarity in the New Lands. ((There is not enough information to say from ingame measurements whether or not the New Lands are on a large sphere or on a large plane. -- in computer game space, of course, they are on a plane.))

In-game, given the information on which I based my True Map, and assuming that there is a possibility of 5% error (assumption for the purposes of demonstration -- my actual error in lining things up is less than 1%) that might show curvature of the surface, the *minimum* diameter of Atys is 220 km. Much more likely, given that it has an atmosphere, is > 8,000 km. ((Of course the atmosphere could be held in by technological or magical means, but unless we have a substantial diameter the gravitational constant would be very low. I think we can discount artificial gravity applied on a planetary scale.))

The only way we would never see any trace of the star is if we were tidally locked to the star itself. A moon or asteroid that is tidally locked to a planet will still complete exactly one rotation per one revolution of its planet- The dark side of earth's moon gets the same amount of light as the light side, except it is a new moon when the far side is getting direct sunlight.

Yes, I think the L1 point is a likely place for Atys. Otherwise, since we appear to be so close to a larger ringed planet I would expect atys to be captured as a satellite, collide with the planet, or be otherwise flung from the larger planet's path :( Based on the current sky animation, there is no evidence that we orbit the ringed planet- and that planet's appearance near our magnetic north pole could just be coincidence, rather than tidal locking (which I don't think occurs with trojans since they are at a point where the planet's and star's gravity negate each other).

Placio -- Yes, I meant -- tidally locked to the star, not to a planet.

In the Trojan position, it would take very little effort (comparatively speaking) to stabilize the planet, and the motion of the ringed object could be some sort of librational motion (which would be emphasized due to the fact that we wouldn't have the high angular momentum to keep the pole in place.

I love this post/thread. I have often in the back of my head wanted to start studying the stars and planets around Atys when I got time, but have been busy lately. I am so happy this club or association has started, May I join?

I have no idea how to determine things such as in your discussion. I have often wondered how astronomers through ancient history have discovered things like if (OC: the sun revolved around the Earth, or visa versa. How a dot in the sky is either a sun or a planet, and the time it takes to go around the Sun, and things like these.) It takes real time and thinking I guess.
I guess i will have to use my brain and try to contribute. In the mean time, I look forward to more discussions on this subject.

-Thanks for starting this discussion!

~Naema

Welcome Naema! Everyone is welcome :) We just need to take what we can observe, offer possible solutions, and then see which solution would fit best. And we can only decide on a best fit, since the animation of the sky is not that scientifically accurate.

But..... It's MAGIC!!!!

Just saying....

ok, yes, in character even Kara tech is "magic," but OOC even "magic" could be explained with science.