From: mikkelhaaheim@gmail.com   
      
   On Monday, February 27, 2017 at 12:01:11 AM UTC+1, MrAnderson wrote:   
      
      
   > There is star of Sun type, it has one main rocky planet, the Arda, and two   
   other habitable rocks, with one being a bit closer to star than Arda and   
   second one being a bit further. In My first ideas all three planets were in   
   triangle, and distances    
   between them were always the same. First question, is it possible to work and   
   be stable for billions of years?   
      
   Unlikely. There are only two means for objects in orbit to remain in fixed   
   positions relative to one another: either they are actually in the same   
   (circular, not non-circular elliptical) orbit, or there is a Lagrange   
   relationship (at least two would need    
   to be stationed at Lagrange points, while the third is either also positioned   
   at a Lagrange point for another body -perhaps the gas giant you were speaking   
   of- or would serve as the second body anchor for the Lagrange points). It is   
   very unlikely that    
   these planets would remain stable at the Lagrange points for such an extended   
   time, unless (as Mark indicated) they were placed there by an advanced alien   
   species. As for the co-orbital arrangement, once you add the gas giant, this   
   arrangement would no    
   longer remain stable. The arrangement itself would be virtually impossible   
   without intervention.   
   That said, things become rather more flexible if the arrangement were just   
   NEAR same distance. This brings up a question I have: when you say that the   
   distances are always the same, does this mean that the respective distances   
   don't vary, or does it mean    
   they are all equidistant from one another? I ask because you describe their   
   orbital arrangement as a triangle... which is ALWAYS the arrangment of any   
   three bodies in space, unless if they just happen to line up perfectly. So,   
   why do you specify this? Do    
   you intend that the arrangement is equilateral? Or is it just to point out the   
   nature of their fixed relative position?   
      
   > The system also has at least one gas giant with moons, and some other   
   bodies, but that's to be designed in future.    
      
   The gas giant could exlpain the triangular relationship by explaining that the   
   planets are located at three of the Lagrange points of the gas giant.   
   Actually, this arrangement COULD possibly occur naturally under such   
   conditions. I have seen an animation    
   of the trojan asteroids, and it was interesting to me to observe that the   
   asteroids were naturally forming a triangle anchored at the Lagrange points.   
   This suggests to me the possibility that, given enough time and the correct   
   asteroidal composition, the    
   asteroids could eventually form into moons or planetoids.   
      
   > can stars be around half light year distant from each other and have   
   planetary systems and be stable?   
      
   I don't see why not. The only concern is whether there would be enough mass   
   for planets to aggregate, since the stars would use up most of the nebular   
   mass available at the stars' formation.   
      
   > Human race travelled to the two other planets in its system,   
      
   Earth humans or Arda humans?   
      
   > colonized them, and for around 100 years there was struggle with   
   establishing colony, some riots, sovereignity of colonies etc. In meantime   
   expeditions were sent to other systems, and colonization started in them.   
   Colonized planets were used for mining    
   by Arda, and that made colonists very unhappy. (here comes the need for some   
   McGufinnite I think, because who would want to ship some ordinary metals    
   through lightyears of cold space, that's just too expensive)    
      
   Think more in terms of shipping products and produce (etc).    
   Different planets will have different climates, different soil compositions,   
   different blends of elements and minerals, etc. This means that similar crops   
   will very likely have VERY different flavours, as will other natural products.   
   To give you an    
   example that is closer to home: dairy products such as milk differ greatly   
   between different regions, even within the same country. Dairy from Isigny,   
   France, for example is considered by chefs as the single best, worldwide... I   
   can personally attest    
   that its flavour is far superior to any US dairy product. Similarly, the   
   flavour of wines depends not so much upon the genetics of the grape vine, but   
   the soil it grows in. Two identical grapes (genetically) will have very   
   different flavours depending    
   upon where in the world they were grown.   
   Outside of these natural regional (or planetary) differences that can not be   
   duplicated elsewhere, there is also the factor of different kinds of artisanal   
   products. Different regions typically develop different products as a factor   
   of culture. In a    
   global (or systemic) economy, appreciations for products from different   
   cultures is routinely cultivated. Of course, there is also the factor of   
   regional (planetary) specialisation: different cultures in shared trade   
   environments tend to specialise the    
   products they make, encouraging trade for products, even though the same   
   products COULD be made by both parties.   
      
      
   > Interstellar vehicles are mostly powered by antimatter, but there are some   
   odd ships powered by Bussard Ramjets, laser sails or even blackholes (what do   
   you think about last one?).    
      
   Limited to extremely advanced societies, but a source of excellent potential.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)