World Composition and TNE
Replies:
- #4973 TNE by Hans Rancke-Madsen
Hi again, Well, I seem to have got some response to my posting... Catie Helm([email removed]) writes: > Now about Corran's proposed UPP scale, based mostly on planetary > composition, which translated to rocks, solid cores, molten cores, > etc. I actually stole these classifications from the World Builders' Handbook by DGP, in a vague attempt to fit in with some previously published information. The World Builders' Handbook basically uses these to split planets up into density categories: Icy body = 0.18 to 0.48 earths Rocky Body = 0.50 to 0.80 earths Molten Core = 0.82 to 1.12 earths Heavy Core = 1.10 to 2.25 earths OK, let's try discarding the idea of whether or not the core is molten or not, and just stick with categories such as "Icy body", and three grades of Rocky bodies: "Light", "Medium" and "Heavy". I'm pretty sure it doesn't matter to the average player whether or not the core is currently molten. Actually I'll take that back - molten cores and so forth would probably affect the existence of magnetic fields, radiation belts, volcanic action (expert opinions welcome :-), so it probably would affect things. In fact I suppose a "molten core" icy body could be an icy body with liquid underneath a crust of ice (I think Europa is thought to be like this?). Nevertheless gravity and atmosphere are far more fundamental... One thing I'm unsure about is where a moon like Io fits into the scheme of things: it's certainly not icy, does it have a rocky core? what's it's density? Should the "icy body" category contain strange bodies like Io? OK, so now we can work out the approximate atmospheric pressure: assume that icy bodies have a density of 1/3 of that of earth (an over-estimate?), light rocky bodies have a density of 2/3, medium rocky bodies have a density of 1 and heavy rocky bodies have a density of 4/3. Then the formula is: density*size/8 (which incidentally is also the surface gravity). In terms of the original traveller atmosphere densities (vacuum: 0 atm, trace: 0 - 0.09 atm, v. thin: 0.10 - 0.42, thin: 0.43 - 0.70, std 0.71 - 1.49, dense: 1.50 - 2.49) we have: size 0/S 1 2 3 4 5 6 7 8 9 A d "icy" vac tr tr vt vt vt vt vt vt vt th e light vac tr vt vt vt th th th th st st n medium vac vt vt vt th th st st st st st s heavy vac vt vt th th st st st st de de Consequences: Much fewer worlds with _no_ atmosphere, much more with very thin atmospheres, fewer worlds with dense atmospheres, and probably fewer with standard atmospheres. It also gets rid of my original gripe about small worlds with normal atmospheres. Problem: I notice that the Moon (size 2, density light) and mercury (size 3, density medium) should have very thin atmosphere (Moon: atm pressure approx 0.16). This seems too high (according to the rules you could breathe on the moon with the aid of a compressor)... I suspect it is a problem with the pressure = gravity approximation. Perhaps larger world sizes should be allowed? Solution: Modifiers: If the world is in the inner or habital zones and has a size of 0,S,1,2,3, then decrease the atm type by one (eg. th -> vt -> tr -> vac), which solves the problem of Mercury and the Moon. Any other suggestions, folks? Right, so then there's only atmospheric composition left, and that can be summarised into the following categories: OK to breathe:Standard 02/N2 type mix Bad news to breathe:Tainted 02/N2 type mix Really bad news to breathe:Exotic Wear your protective gear:Irritant, Corrosive, Insidious Finally there are the weird ones: D (dense, high), E (ellipsoid), F (thin, low). These are really atmospheric pressure considerations, (in fact ellipsoid is really a planetary _shape_ consideration). So there are 2 choices here: If you want good compatability with the previous traveller system, then consider the following: Composition Density Atmosphere 0 Icy Exotic, Irritant or Corrosive 1 Icy Standard 2 Icy Tainted 3 Light Exotic, Irritant or Corrosive 4 Light Tainted 5 Light Standard 6 Medium Standard 7 Medium Tainted 8 Heavy Standard 9 Heavy Tainted A Medium Exotic, Irritant or Corrosive B Heavy Exotic, Irritant or Corrosive C Heavy Insidious D Heavy Dense, High E Medium Ellipsoid* F Light Thin, Low * or maybe Insidious if you don't mind incompatibility. If you need to know whether a given atmosphere is exotic, irritant or corrosive, then roll 1D: 1-3 Exotic, 4 Irritant, 5-6 Corrosive. The only real difference here is that 3 goes from very thin to exotic/corrosive, so concievably a large world could be having its effective atmosphere type changed from 3 to A or B under the old system, however the atmosphere density will only change from 3 to 4 or 5. All in all, I think it should work OK. Now for the virus story: Hans Rancke-Madsen [email removed] writes: >> The Virus is going to make technological advance extremely difficult in >>affected areas, however, so that recovery may well be not possible - every >>time that a civilisation gets to TL 7 or so, it will almost surely start >>using silicon chips, > >What's the bet that someone will develop a non-silicon chip before the >Cymberline predator has been on the scene 10 years? Yes, but you seem to have missed the point: is such a substitute going to be accessible to a TL7 or 8 world? Indeed I think I mentioned that I would be surprised if your average TL15 ship's computer used silicon chips. The point still remains: unless the virus is not much of a threat, there is not going to be any easy way for a world to develop to TL9 and get interstellar travel (or if they do, it won't be long before the virus finds them and eats all their electronics). > >> Realising the military potential of this discovery for the Domain of >>Deneb, the development of stutterwarp drive ships are fast-tracked and the >>problems with the electronics surmounted by new (and incidentally Virus- >>proof) technologies. By the time the Domain of Deneb is threatened by the >>Virus a small squadron of fighting ships is ready. This handful of ships >>then defeats a Virus Armada coming through Corridor. > >> [Deneb then helps] >>the Aslan Heirate (in exchange for the Ihatei to stop their attacks), > >The ihatei isn't even a real threat without the virus. With the Aslans >plagued by the Virus and Deneb controlling virus-free, stutterwarp ships >there's only one way the Aslans are going to get any: As loyal vassals >of Archduke Norris. True, you have a valid point here. Then again, there is probably no way that Deneb could even contemplate conquest of the Aslan Heirate (especially if they have had major problems with virus incursions), just like they could not contemplate annexing the Zhodani. In addition, the Domain seems to be non-expansionist. I can see that a hard-pressed Deneb might reach some sort of agreement with the Aslan (after all, the Domain is really only fighting the ihatei, not the Heirate itself). Admittedly, in the long run the Heirate is defenseless against Deneb, but I s'pose that once it is known that stutterwarp is possible, the Aslan & Zhodani may well develop it fairly rapidly. - -or- Maybe the Hivers help out the Aslan. Or sell the stutterwarp to them after Deneb has defeated the virus... Any other suggestions? It's late. I'd better stop this. 8-) See ya 'round Corran Webster [email removed]