Ryzom

Ah Atysian Astronomy, my favourite subject. Doing a physics degree obviously means I have an interest in such things, and I have come up with several theories concerning this:

1 - The Sun is a normal sun, Atys rotates around the ringed planet we see in the sky (as does the other moon), but at an angle to the normal planetry plane, and does not spin relative to the sun. As a result we always see it at the same point in the sky, and gets closer and further away due to orbiting the planet. However, the sun changes in visible size so much that this would have to be a very big lunar orbit relativly speaking.

2 - The Sun is not a sun at all, it is a technological or magical device in the sky that changes size due to the seasons, it is in a geostationary orbit around Atys, which rotates around the ringed planet as normal.

3 - The planet rotates around Atys, personally I have my doubts about this, but I can't rule it out either. However, if Atys was the main planetry body, and the sun was a real star, Atys would have to have a very eliptical and fast orbit.

4 - The sun is on the other side of Atys, it is relected in a mirror like device to give light to our "dark" side of the planet, the part we live on. The sun changes position wrt the mirror (which is in geostationary orbit above Atys) and its viewavle size variation is amplified due to the reflective qualities of the mirror, and the current angle the real sun makes with the mirror. This theory I love, although not the most likely it does solve a few problems in an easy way, such as the sun in the same spot in the sky, the hugely eliptical orbit required, or large lunar orbit is not nessecary and it is easier to explain why the same part of the ringed planet is always visible.

Hope you like and understand the theories, I have a few more but am still working on them so I won't reveil them yet

-Kibs

I love your mirror theory Kibs
I'm puzzled by those who think that Atys's star changes size because I've never noticed this. It simply waxes and wanes, if you ask me, as it spins upon its own axis. The picture of Atys linked to earlier in this thread could be simply misleading. The reason that the star is always in the same place in the sky, I believe, is that Atys is a tiny little spot upon the inner surface of a dyson sphere. The other celestial bodies could be orbiting our star within the sphere at about the same speed, but their ethereal appearance and jumpy movement always led me to believe that they are really projections upon the sphere's surface. It's a planetarium

Edit: link added

jamela wrote:I love your mirror theory Kibs
I'm puzzled by those who think that Atys's star changes size because I've never noticed this. It simply waxes and wanes, if you ask me, as it spins upon its own axis. The picture of Atys linked to earlier in this thread could be simply misleading. The reason that the star is always in the same place in the sky, I believe, is that Atys is a tiny little spot upon the inner surface of a dyson sphere. The other celestial bodies could be orbiting our star within the sphere at about the same speed, but their ethereal appearance and jumpy movement always led me to believe that they are really projections upon the sphere's surface. It's a planetarium

Well as for the sun changing size, thats how we can tell the difference between night and day, the sun is always in the same place in the sky. Normally this would suggest constant day or constant night depending which side of the planet you were on, however it "appears" to get smaller at night and larger during the day, it also appears to change with seasons. The fact that there is night and day cycles would seem to suggest that it isnt as normal a star as it first appears.

kyerna wrote:Besides, we all know what horror the Fyros unleashed upon the bark during the time of the Ancients. Do we want to risk going deeper and possibly awaken something worse from it' s slumber while we are still trying to overcome the last threat?

Knowledge requiers sacrifice and facing dangers. Sorry to disagree with you, Kyerna. And homins have the natural gift of curiosity. Kitins were unleashed by digging of course, but this is only one way of seeing things... They are intelligent even if in a different way than us. Maybe it was better we came in touch with them earlier, and not when they decided they were ready to emerge, before they had all the coordination we know now they are capable of.

This doesn't mean of course we should go blind and unleash any perils whose consequences we can foresee.

khyle wrote: And, now completely offtopic, only the karavan could suggest something like cutting down the branches

As far as I know cutting branches out of trees is a regular care for them, sometimes even a lifesaving technique

kibsword wrote: 4 - The sun is on the other side of Atys, it is relected in a mirror like device to give light to our "dark" side of the planet, the part we live on. The sun changes position wrt the mirror (which is in geostationary orbit above Atys) and its viewavle size variation is amplified due to the reflective qualities of the mirror, and the current angle the real sun makes with the mirror. This theory I love, although not the most likely it does solve a few problems in an easy way, such as the sun in the same spot in the sky, the hugely eliptical orbit required, or large lunar orbit is not nessecary and it is easier to explain why the same part of the ringed planet is always visible.

This sounds as a fascinating theory ... so is the directly lighted face of the planet uninhabitable? Because of too much closeness to the sun? And why can't we reach that part whatever far we're going? Anyway the tree form of Atys raises the problme if the spatial body is round at all...

If Atys is indeed round and isnt growing straight "up" towards the light it would suggest it was illuminated equally on all sides , could it be that Atys sits at the mid point of more than one sun ?

The day-night cycle could be explained if there was a transparent "shield" that circled Atys and partly blocked out the light -a shuttering effect , maybe its the Karavans space station orbiting the planet and casting its shadow ?

Slightly Off topic, but guys...
If Atys is a plant... Growing up from a "normal" planet Core.
Where does it get it´s nutrients? Is it a plant-perpetuum-mobile?
Is it completely self sufficient?
And if we, Karavan or Kami, continue to deplete these ressources by digging deep into the Plant, then don´t we destroy our own world?
No Plant can feed on Light alone.

A friend once suggested that Atys is in reality a Bonsai-Tree, sitting in a Fishbowl on the Desk of Jena, the Sun is a Reading-Lamp.
The Kitin are "normal" Ants and Bugs. And the Karavan are so to say, Micronauts.

Acridiel

One possibility I'd like to add that I haven't seen mentioned yet; the sun of Atys could be a periodic star. There are stars that vary hugely in brightness in a periodic manner. Though a period of 24 hours would be the fastest variable star ever.

Perhaps the fast pulsing of the star is a warning sign of the star's instability, and that it's about to explode into a red giant star The Karavan did always hint Atys would soon be destroyed in a blaze of fire...

pr0ger wrote:The biggest and scariest fact is, if this observation is true, it means Atys makes a revolution around the sun in 24 hours and rotating on itself in 24 hours... wow how fast does atys moves then ??

If Atys revolves around the sun in 24 hours, all 4 seasons would pass in those 24 hours. Assuming ofcourse the seasons are caused the same way as on Earth, by the non-zero angle between the Earth's rotation around the sun and the rotation around it's own axis. But since the time that all 4 seasons pass is called a "cycle", it has to be about something revolving around something.

Speaking of, does the number of hours of daylight vary between the seasons? That'd be a pretty clear indication if they're caused by Atys' rotation around the sun or not.

kibsword wrote:3 - The planet rotates around Atys, personally I have my doubts about this, but I can't rule it out either. However, if Atys was the main planetry body, and the sun was a real star, Atys would have to have a very eliptical and fast orbit.

Have you seen how big that thing is? Our own moon is one-third the diameter of Earth, and is only a little tiny dot in our sky. If we assume this planet is at comparable distance, it has to be huge to cover that much of the Atys sky. At least 100 times the diameter of our moon. Definitely larger than Atys. For it to be smaller than Atys, it'd have to be so close it would've long ago been pulled apart by Atys' gravity.

Actually, I think for anything to appear as such a huge object in the sky, its gravity would pull Atys apart anyway. So we could conclude it's not a real planet. Or that Atys' branches and roots just keep the planet together much sturdier than a normal ball of rock like Earth. Still, we'd have to be experiencing huge tidal forces.

petej wrote:If Atys is indeed round and isnt growing straight "up" towards the light it would suggest it was illuminated equally on all sides , could it be that Atys sits at the mid point of more than one sun ?

Hmmm, Atys right in the center of a double-star system with both stars lighting up one side of the planet... That would explain the stationary sun. But any planet right in the middle of two stars would either be pulled apart by their gravity, be pulled into one of the stars, or be slingshotted into space.

acridiel wrote:Slightly Off topic, but guys...
If Atys is a plant... Growing up from a "normal" planet Core.
Where does it get it´s nutrients? Is it a plant-perpetuum-mobile?
Is it completely self sufficient?
And if we, Karavan or Kami, continue to deplete these ressources by digging deep into the Plant, then don´t we destroy our own world?
No Plant can feed on Light alone.

A closed ecology doesn't need any additional nutrients, just energy. Earth's life ultimately gets all their energy from the sun. Then Atys also has that big gas planet in the sky, apparently pretty close. Jupiter's moon Io, being very close to the planet, has vulcanic activity as a result of the energy delivered to it by Jupiter's tidal forces. Thirdly, look up at the sky of Atys, and it looks like a meteor shower rages every day there, probably coming from the gas planet's ring. So I think Atys receives plenty of energy.

Come to think of it, wouldn't those meteors deposit minerals on Atys?

sidusar wrote:Come to think of it, wouldn't those meteors deposit minerals on Atys?

I'll follow this thought in this new thread...

sidusar wrote:One possibility I'd like to add that I haven't seen mentioned yet; the sun of Atys could be a periodic star. There are stars that vary hugely in brightness in a periodic manner. Though a period of 24 hours would be the fastest variable star ever.

Don't forget that the fact that our star's period has been divided into 24 hours is no indication that an Atys hour is equivalent to an Earth hour. Subjectively, it's about 3 minutes, objectively, who knows?

Recommended reading: Hothouse, by Brian Aldiss

Hehe, Just a though... perhaps the sky and cosmology of atys didn't quite recieve at wisdom of numerous physicists and astrologists. And is influenced more by the artists hand and the story writers tale, than science. I don't query the physics of making a spear from bark some fiber and a shell or pyr's forge being made of wood or why they even need a forge or that a small cuttler needs to kill 3 arana every hour or a homin even if he's never eaten one. Sometimes better to take things at face value as its how it is, as the 'why' just perplexes. But just a thought.