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Post by CELS on Dec 13, 2004 8:03:35 GMT -5
Well, Archaios and Proteus in the Archaios subsector have ellipsoid atmospheres, but Kage has a bit of a problem with them, in retrospect. I can't really say I blame him, since I don't really understand how an atmosphere can be ellipsoid with there being a central point of gravity.
A while ago, I googled for information on ellipsoid atmospheres, and came up empty except for a few sites which, unsurprisingly, were related to Traveller.
Obviously, we need to find out what to do with these 'ellipsoid atmospheres'. Are they unrealistic? Should we just read the E atmosphere codes as 6 or something else?
Previously, I've been very unwilling to change what I've written for Proteus, but now I just want to finish my worlds in the Archaios subsector so that when HighInquisitor and ZidagarDinoman get back, and when Destecado finds the time and motivation to take a look at Sistina, we have a subsector nearing 'completion'.
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Post by Dazo on Dec 13, 2004 8:11:53 GMT -5
*Tapping foot, arms folded* Ahem, I think we discussed this did we not  Ellipsoid atmospheres, well saturn has an ellipsoid atmosphere, this is due the very very rapid rotational speed, which imparts centrifugal forces at the equator and causes them to bulge, whereas at the poles it becomes flattened. This in my opinion is the only explanation for an atmosphere which is ellipsoid, rapid rotation.  It would also have possible gravitational knock ons, in that unless the gravity was high enough anything on the equatorial regions of your worlds CELS would probably be flung of into space or smooshed flat. And I would change it to a 7 or 9 atmosphere, as they are supposed to be polluted worlds aren't they. |
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Post by CELS on Dec 13, 2004 8:22:05 GMT -5
I know that we've touched on the subject many times (though I can't really remember that we had a solution to the problem), but I wanted to start a seperate thread to get more attention and make the discussion tidyer.
An ellipsoid gravity field? Sounds messy, but it does make sense. But I guess that there are varying degrees of an ellipsoid gravity field. I don't want tech priests living on the equator of Proteus to be fifteen feet tall.
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Post by Dazo on Dec 14, 2004 11:42:58 GMT -5
I'm really not sure ellipsoid gravity feilds exist, and even if they did there would be no reason to suspect the atmosphere would also be elliptical.
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Post by Kage2020 on Dec 14, 2004 16:40:32 GMT -5
This is only related to the completion comment, but remember that the world SRs have to be ratified before moving into the Archive.
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Post by CELS on Dec 20, 2004 10:37:09 GMT -5
So where are we on Archaios Prime and Proteus then? They both have ellipsoid atmospheres, of varying degrees. Archios' atmosphere is barely ellipsoid, whilst Proteus' atmosphere is quite ellipsoid. What changes do I need to make before these SRs are 100% approved and ready to go?
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Post by Sojourner on Dec 20, 2004 11:39:59 GMT -5
Very strong solar wind, possibly? As a mechanism for the atmospheric distortion?
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Post by CELS on Dec 20, 2004 11:48:42 GMT -5
I don't follow. Care to elaborate?
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Post by Destecado on Dec 20, 2004 13:41:51 GMT -5
Very strong solar wind, possibly? As a mechanism for the atmospheric distortion? The solar wind wouln't cause the ellipsoid atmosphere. The solar wind does cause compression in the magnetosphere, ionosphere, and the atmosphere...but I don't think that was what CELS was looking for. Elliptical atmospheres can be caused by extreme tidal stress as well as very fast rotation. Is either world orbiting its primary star closely or a moon of a large gas giant....what are the rotational velocities? The ellipsoid nature of the atmopshere may lead to additional outgassing (loss of atmosphere) near the equators. This occurse, becuase the bulge causes the gasses to be further from the center of gravity of the planet so gases that may otherwise not escape might with the further distance be able to escape into space...It all depends on how extreme the ellisoid effect is. The planet may eventually lose all of its atmospher as the process continues. It could be that the air would be thinner the closer you come to the equater...this could skew the atmospheric pressure. I'll see if I can find an equation for calculating the drop in atmospheric pressure caused by the ellipsoid nature of the atmosphere. With this drop in pressure, the limit at which the air will be breathable will also deccrease. Elevations at the poles where an individual can breath normally, may at the equator require specialized equipment. The habitation for humans without the aid of specialized equipment will thus be reduced, the close you go are towards the equator. Maybe technological means exist in the 40k future to counteract this natural loss of atmosphere....such as large atmospheric processors that pump gasses back into the depleted atmosphere. |
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Post by CELS on Dec 20, 2004 13:59:23 GMT -5
The worlds are Archaios Prime and Proteus. Both are close to their star (both have M-V stars), but no closer than other worlds with similar stars. 0.2 AU.
Rotational speeds are quite standard at the moment; 30 hours for Archaios and 80 hours for Proteus. It seems I'll have to increase these considerably though. If they're the same speed as all other worlds in the Anargo sector with M-V stars, then there's no reason why these would have ellipsoid atmospheres and the others would not.
As it stands, Archaios has only a very slightly ellipsoid atmosphere, which is most dense at its equator. Proteus has a more ellipsoid atmosphere, with 2.2 atm at the equator and 0.3- atm at the poles.
I don't want Proteus to lose significant amounts of atmosphere, so if that would happen with such an ellipsoid atmosphere, the planet will need some kind of graviton satellites like Mars used to have, in order to maintain the atmosphere.
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Post by Destecado on Dec 20, 2004 14:28:31 GMT -5
The worlds are Archaios Prime and Proteus. Both are close to their star (both have M-V stars), but no closer than other worlds with similar stars. 0.2 AU. We do have alot of stars in the ASP which are red dwarfs. While the habitable zone of red stars falls within the zero orbit, the distance from the primary within this orbit may be played with a little to place the planet closer to the star (within the zero orbit). This along with an increase in rotation velocity should provide the ellipsoid atmosphere. Since the ellipsoidal effect on the atmosphere of Archaios is slight, it will only deviate slightly. As for Proteus....increasing the rotation velocity would probably be best. An 80 hour rotational period seems rather long anyway. That equates to what, about a 40 hour work day....no wonder Proteus is so productive. As it stands, Archaios has only a very slightly ellipsoid atmosphere, which is most dense at its equator. Proteus has a more ellipsoid atmosphere, with 2.2 atm at the equator and 0.3- atm at the poles. Well since you have the figures already, I don't need to go searching for an equation to calculate it. I don't want Proteus to lose significant amounts of atmosphere, so if that would happen with such an ellipsoid atmosphere, the planet will need some kind of graviton satellites like Mars used to have, in order to maintain the atmosphere. With how pronounced the ellipsoidal distortion in the atmosphere is, I can't see it not losing atmosphere...although how much is actually lost would be a calculation is am loath to attempt at this time. Proteus will definitely need graviton satellites or some way to replace the lost atmophere. Other than shifting the orbit of the planet or slowing down its rotation, I see no way around it. |
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Post by CELS on Dec 20, 2004 14:41:44 GMT -5
We do have alot of stars in the ASP which are red dwarfs. While the habitable zone of red stars falls within the zero orbit, the distance from the primary within this orbit may be played with a little to place the planet closer to the star (within the zero orbit). Well, I could make it 0.15 AU, as opposed to the standard 0.2 AU LoL The thing is- these figures were pretty much pulled from the darkest pits of my imagination. If you have a more scientific method, I'm all ears! I'll just cross my finger and hope Kage doesn't mind the presence of graviton satelites. They might have to be Age of Technology relics, since I've only ever heard of them used on Mars in the Age of Technology. |
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Post by Destecado on Dec 20, 2004 16:23:36 GMT -5
Well, I could make it 0.15 AU, as opposed to the standard 0.2 AU That sounds reasonable...if we're talking about Proteus, then this helps to make its base temperature of 61 degrees C (141.8 degrees fahrenheit) more understandable...although it also means that the planet is mostlikely going to be tidally locked. The thing is- these figures were pretty much pulled from the darkest pits of my imagination. If you have a more scientific method, I'm all ears! Well they looked good to me...but I'll see if I can locate or come up with an equation for calculating the difference. I'll just cross my finger and hope Kage doesn't mind the presence of graviton satelites. They might have to be Age of Technology relics, since I've only ever heard of them used on Mars in the Age of Technology. Well it is a Adeptus Mechanicus world IIRC...so such technical wonders shouldn't be beyond them. If he syas these are too high tech, then atmospheric processors at the poles might be the way to go. They don't stop the loss of atmosphere, but they pump new atmospheric gasses in to replace them....sort of like an atmospheric transfussion. |
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Post by CELS on Dec 20, 2004 19:42:23 GMT -5
That sounds reasonable...if we're talking about Proteus, then this helps to make its base temperature of 61 degrees C (141.8 degrees fahrenheit) more understandable...although it also means that the planet is mostlikely going to be tidally locked. Well, it can't be tidally locked, obviously Fantastic! If no one objects though, I'm happy to keep things as they are, without equations. Where would these new atmospheric gasses come from? On another note; Might it perhaps be appropriate to set all worlds orbiting M-V stars in the zero orbit zone as having a certain minimum rotational period? After all, if we're saying that a mere eight hour rotational period is causing an ellipsoid atmosphere on Proteus, then it wouldn't be so great to have three other similar worlds in the Anargo sector, with less than eight hour rotational periods, would it? |
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Post by Destecado on Dec 21, 2004 10:38:28 GMT -5
Fantastic! If no one objects though, I'm happy to keep things as they are, without equations. I'll still look for an equation, but I am happy with the values you have generated. Where would these new atmospheric gasses come from? It could come from the planet itself or from matterial brough in from outside. Oxygen is highly reactive and will bond readily to most compounds. The atmospheric processor may extract this and other elements from crust of the planet. Nitrogen and other gasses may also be extracted in this manner. It adds an interesting twist to Proteus. Not only does it consume vast resources from other planets to make useable goods and machines of war, it also consumes other planets to maintain its atmosphere....sort of like the way the emperor feeds on psykers in order to maintain himself. This is the darkside of the Imperium...or at least of the Adeptus Mechanicus, trying to enforce their will over the universe by fighting back the natural process of outgassing...at the expense of others. On another note; Might it perhaps be appropriate to set all worlds orbiting M-V stars in the zero orbit zone as having a certain minimum rotational period? After all, if we're saying that a mere eight hour rotational period is causing an ellipsoid atmosphere on Proteus, then it wouldn't be so great to have three other similar worlds in the Anargo sector, with less than eight hour rotational periods, would it? I just want to make sure that we are talking about the same thing. By rotational period you mean the planet rotating on its access right? If yes, then a rotation period of 8 hours does seem a little extreme. Of course rotational velocity is not the only factor we need to consider when looking at the ellipsoidal effect. We also need to look at the diamtere of the planet, its mass and gravity. Increased gravity will also increase the escape velocity necessary for the outgassing to occur. If a planet is also very large, the compression caused by the fast rotation will be spread over a greater surface area. The bulge at the eaquator will thus be less pronounced than on a smaller body, which could actually bedeformed into an elipsoid body rather than more spherical. This happens in some of Jupiters moons, but is a combination of rotation and tidal forces. Either way, we may definitely need to re-evaluate the rotational periods (again spinning on their access) of these planets. |
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