Terraforming as a Trade Classification

[EDG]

Whatever, Aramis - I was clear enough with what I said for most people. I'm not going to get drawn into another pointless argument with you over a harmless phrase that you've suddenly decided to go off on a crusade against.

Though I didn't even remotely say or imply (or even think) that anyone was an idiot for not knowing that, so kindly don't put words in my mouth. :evil:

"The physics is well known to the scientists who study in that field and are aware of it" - is that clear enough for you perhaps? That's all that matters here.

Also, I think the general response of people here to all this statistical stuff and in the worldbuilding indicates that actually many people have an interest in the subject (even if they're not interested in all the gory details). I'll be able to present the case for my modifications more clearly tomorrow when I post the stats for the UWPs generated using my proposed tweaks to the MGT system. But the general point is that small worlds can't hold atmospheres, and that's just how the universe works. Rather than waste 25 more years being lumbered with a flawed system that looks more and more ridiculous from a realism perspective as time goes by, I'd much rather we take the jump and fix the damn thing now.

Now let's move on, shall we?

 

[Golan2072]

I have all the Traveller materials produced by GDW and terraforming is in the realm of not discussed vs non-existant.
Sorta like most players who had the original three books thinking that aliens where not part of the game until the adventures and library data started to be produced.
Even robots where not discussed a lot until book 8.

Terraformation is a very universe-specific subject. In the OTU you have high-TL Ancients as well as millenia of Human habitation (which means that terraformation is possible on some worlds even with slower and lower-tech processes taking a long time to be complete). In other universes things could be different - just think of a near-future universe where there were no OTU-style Ancients and where Humans have visited the stars only in the recent few decades - you will have far less habitable worlds and far more dome/cave/tent colonies. Or a universe where an Aliens-style terraformation technique allows a quick (relatively speaking - i.e. a few decades) transformation from an uninhabitable world into a marginally inhabitable one.

 

[chrisr]

Personally, I feel that teraforming should be kept to relatively minor adjustments to the UWP.
Atmospheric terraforming should be restricted to the removal of a taint, exotic to non-exotic, corrosive to exotic etc.
Hydrographic (surface water) terraforming to +/- 1 (ie 10%).
I think this is pretty close to what appears in WBH.

When it comes to previously published material, IMTU I change the sizes of small worlds with breathable atmospheres to a minimum 4 for very thin atmospheres ,5 for thin or standard and 6 for dense. I figure size has the least effect to a campaign except for travel times.

Oh and hello everyone, this is my first post on this forum

 

[pasuuli]

Well to be clearer - the terraforming excuse doesn't work on the small planets.

Well... since we've never done it before, that's not strictly true, I think. It does seem ridiculous to think that tiny worlds like the Moon could be terraformed, but then I'm thinking about an Earth atmosphere. Perhaps there are alternatives we haven't considered. Certainly there are things we've not thought of, like Arthur C. Clarke implied with his famous statement about technology and magic.

But still basic physics tells us this is not a viable course of action, and apart from a few noble exceptions, this kind of handwavium isn't really part of the Traveller ethic.

And then there's logic to consider. Even with magic technology, it would still be easier (therefore cheaper) to terraform the bigger rockballs (5+) rather than expend resources on the tiny worlds.

Probably better to eliminate such nonsensical results from the system. If a setting author really wanted a size 1 garden world, then he could add it by fiat. The generic system should not be producing them.

Surely gravity doesn't have to stop us. Can't there be other ways of holding an atmosphere that doesn't involve changing the gravity of a world or building a roof?

 

[EDG]

Surely gravity doesn't have to stop us.

I'm afraid it does have to stop us. That's reality for you, it tends to work in ways that we don't want it to.

Can't there be other ways of holding an atmosphere that doesn't involve changing the gravity of a world or building a roof?

Nope. The only alternative is to be colder - the only reason that Saturn's moon Titan can hold onto a thick atmosphere because it's so far from the sun. And obviously, cryogenic temperatures aren't conducive to oxygen-producing life.

If you suddenly teleported Titan to Earth's orbit, the increased temperature would drive off all the gases in a very short timescale (weeks at most, probably) and it certainly wouldn't be able to hold onto nitrogen or oxygen or even carbon dioxide.

 

[Zowy]

I dislike haveing to use TechoMagic, to explain away things like low G worlds with to much atmosphere. Haveing so many mid to large population, low Tec worlds that need higher Tec lifesuport than they can make. Interastellar commerce, that is in many ways unsound. Due to high overhead costs and the many dangers of the space lanes.

 

[pasuuli]

The only alternative is to be colder...

Can the atmosphere be heavier, or clingier?

 

[EDG]

The only alternative is to be colder...

Can the atmosphere be heavier, or clingier?

"clingier"?!

No. Gases have molecular weights (determined by the atoms that their molecules are made of) - that's unchangeable. Oxygen has a molecular weight of 32 (since it's a molecule made of two Oxygen atoms of atomic weight 16 each). Nitrogen is 28. Carbon Dioxide is 44. Water is 18 (16 for the oxygen plus 2 for the two Hydrogen atoms).

The physics tells us the minimum molecular weight (MMW) that a planet can hold onto given its gravity and temperature (the temperature bit is fuzzy, since it really depends on the exosphere temperature more than the temperature at the planet's surface). And there's complications from solar wind stripping gases off the top of the atmosphere, and particles from the planet's own magnetic field doing the same thing. But broadly speaking and for the sake of simplicity here, atmospheric retention is determined by gravity and temperature - the hotter the world is, the less it can hold onto. Also, the less massive (i.e. smaller) the world, the the less it can hold onto.

If the MMW retained is say 15, then we know the planet can hold onto gases that are heavier than that (including N2, O2, CO2, H2O). So you can have a breathable atmosphere.

Alternatively, if the MMW retained is (for example) 35 then the planet can't hold onto anything lighter than that (including N2, O2, CH4 (methane), NH3 (ammonia), H2O), and the only gas it can really hold onto is CO2 (because it has a molecular weight of 44).

A size 1 world of any reasonable density (3500 kg/m3) in the habitable zone has a MMW of about 550, and a size 2 has an MMW of about 140. Since there aren't any atmospheric gases that heavy, they can't have atmospheres.

A normal size 3 world has an MMW of about 61 - again, no atmosphere. A dense (5500 kg/m3) size 3 world in the habitable zone however has an MMW of 39, so it can just about cling onto CO2 only. So there's a chance of a trace (Mars-like) Co2 atmosphere.

A normal size 4 world has an MMW of about 35, so it can have a decent CO2 atmosphere (trace or exotic). A dense (5500 kg/m3) size 4 has an MMW of 22, which means it can hold onto N2 as well as CO2. It can also hold O2... but it can't retain H2O, which means it'd lose any water it had over geological time. No water means no life, which means no oxygen. So size 4s should really only be able to have exotic atmospheres... but these worlds are right on the borderline of habitability (they're also too small to have plate tectonics, which may be another essential for a habitable world because that sets up carbon cycles and so on).

A low density (3500 kg/m3) size 5 world has an MMW of about 22, and so suffers the same problem as the high density size 4. But denser worlds can be more common at this size, so realistically the density is usually going to be around 4500 kg/m3 - 5000 kg/m3. That pushes the MMW to below 18, which means they can hold H2O, and thus retain oceans and thus produce oxygen, so they can have breathable atmospheres. Which is why I say that a world has to be size 5+ to have atm 2-9.

And obviously size 6+ worlds have lower MMWs, and so can hold O2 and H2O easily.

So that's how it works, in the habitable zone at least. If we go further out from the star then the MMW retained for a given size decreases due to the lower temperature, which means that smaller worlds can hold onto atmospheres (which is why Titan can retain a thick Nitrogen atmosphere even though it's size 3 and in the Outer Zone). Go closer to the star than the habitable zone and it becomes a lot harder to hold onto the atmosphere (in no small part due to the more intense stellar wind closer to the star).

 

[pasuuli]

Fascinating! Thanks for explaining.

Maybe there's some interaction between some types of atmosphere and water that can act in the same way surface tension acts on the walls of a test tube.

Or, assuming an atmosphere implies life. Maybe life if required can make an atmosphere 'stick' to the surface.

Maybe life can replenish an atmosphere faster than it can bleed off.

Capturing water is an interesting problem.

 

[AKAramis]

Fascinating! Thanks for explaining.

Maybe there's some interaction between some types of atmosphere and water that can act in the same way surface tension acts on the walls of a test tube.

Or, assuming an atmosphere implies life. Maybe life if required can make an atmosphere 'stick' to the surface.

Maybe life can replenish an atmosphere faster than it can bleed off.

Capturing water is an interesting problem.

Most people don't realize Earth loses a ton or more of atmosphere a day (most of which is pushed away by the solar wind, tho' some is escaping hydrogen and helium).

If it were not for
1) the magnetic fields
2) volcanism

we'd likely have almost no atmosphere, either. The magnetic fields divert most of the solar wind, and volcanism replaces the lost mass from within the interior of the earth.

Life merely alters what the composition of said atmosphere is.

 

[EDG]

Maybe there's some interaction between some types of atmosphere and water that can act in the same way surface tension acts on the walls of a test tube.

No, there really isn't. That's a totally different process.

Or, assuming an atmosphere implies life. Maybe life if required can make an atmosphere 'stick' to the surface.

No, it really can't. The most life can do is absorb some gases (which can then get recycles or locked up in rocks when life inevitably fossilises) and produce other gases.

There's no "clinginess" or "surface tension". A planet holds onto its gases solely because of its gravity and its temperature. A planet can lose its gases if the temperature increases or if external forces like the solar wind increase, or if processes on the planet lock them up in the crust faster than they're produced.

 

[AKAramis]

There's no "clinginess" or "surface tension". A planet holds onto its gases solely because of its gravity and its temperature. A planet can lose its gases if the temperature increases or if external forces like the solar wind increase, or if processes on the planet lock them up in the crust faster than they're produced.

You're missing one element, EDG: the magnetosphere reduces erosion by the solar wind.

 

[EDG]

You're missing one element, EDG: the magnetosphere reduces erosion by the solar wind.

Not necessarily - the magnetosphere can actually send *more* charged particles slamming into the atmosphere because the field can accelerate the solar wind particles (that's why Jupiter's field is so ferocious). Ganymede's polar regions are actually a different colour because of erosion and weathering caused by charged particles in Jupiter's magnetosphere being focussed to where its own magnetic field comes back into the body of the moon at the poles. And that's basically what causes aurorae too.

But that sort of thing is way too complex to model in Traveller.

 

[Sturn]

I know some may yell, but I really don't care that my Size 2 worlds with an atmosphere are anomalies. My players don't have degrees in astrophysics or geology, so they won't notice either. It's a game. Heck, these worlds we are calling unrealistic are displayed across a 2D map. This is Traveller, it was never considered hard sci-fi or realistic, just fun.

That being said, I may use EDG's system to generate new worlds since it appears it will not be more complicated but give more realistic results. No brainer to use it. But am I going to go through all my OTU star maps and start changing sizes and atmospheres? Hell no. 2D maps, wolf and cat men, floating softball palaces, cartoonish 1970's graphics...this is Traveller so I'm not much worried about it being 100% scientific, just simple and fun.

 

[EDG]

I know some may yell, but I really don't care that my Size 2 worlds with an atmosphere are anomalies. My players don't have degrees in astrophysics or geology, so they won't notice either. It's a game. Heck, these worlds we are calling unrealistic are displayed across a 2D map. This is Traveller, it was never considered hard sci-fi or realistic, just fun.

Whether anyone cares about it or not, they're still the result of a broken system. You'd care if the ship design system built engines that couldn't move them, right? Or less obviously, if you couldn't fit enough fuel to run the ship for more than an hour? Even though the problems with world design are less obvious to most people than that, it doesn't mean that they're not worth fixing.

Fact is, despite people's assertions to the contrary, Traveller has tried from the latter days of CT to be hard sci-fi/realistic from a physical universe point of view - all the astronomical stuff about the stars and planets in CT Book 6 Scouts attests to that. I don't care about the realism of jump drives and aliens and all that stuff, that's simply not relevant to that side of the game - just because other aspects of the game aren't realistic doesn't mean that all attempts at realism anywhere else should be dismissed or abandoned.

Although Marc failed in the attempt (not least because several of the tables in book 6 are statistically broken), he was quite clearly trying to give us the tools to produce a more realistic physical setting in book 6 - later on, the rules in WBH and in GT: First In continued that trend.

The changes required to make the stars and worlds physically realistic are fairly minimal. And they're pretty much written now in my rules, so don't require any real effort to include in the game (a no-brainer to use them, as you said).

Obviously people can continue to use whatever they like in their games. But hopefully the UWPs and sample quadrant map that I provided in the EDG Worldgen Stats and UWPs thread (this post, specifically) will persuade you that you don't actually lose anything by making a realistic setting - it doesn't make Traveller any more complicated or any less fun.

 

[-Daniel-]

Just a short statement:

I was happy in my ignorance EDG :wink:

Now that I know there is a problem, I want it fixed. I like that Traveller tries to be as realistic as it can for a SciFi game in such areas.

Daniel

 

[AKAramis]

Although Marc failed in the attempt (not least because several of the tables in book 6 are statistically broken), he was quite clearly trying to give us the tools to produce a more realistic physical setting in book 6 - later on, the rules in WBH and in GT: First In continued that trend.

Neither WBH nor GT:FI were MWM's work... they both reflect outside design teams releasing outside Marc's immediate purview.

 

[EDG]

Neither WBH nor GT:FI were MWM's work... they both reflect outside design teams releasing outside Marc's immediate purview.

So? The point is that they carried on in the same vein as the original Book 6.

(funnily enough, everything released for Traveller outside of Marc's "immediate purview" has IMO been of vastly higher quality than the material released with Marc's involvement or oversight).

 

[Thuban]

Whether anyone cares about it or not, they're still the result of a broken system. You'd care if the ship design system built engines that couldn't move them, right?

The classic Traveller ship building rules produce ships that would melt to slag about a second after the power plant is turned on.*

It hasn't spoiled my enjoyment of the game even a little bit.

Neither have impossible planets.

YMMV.



* Greg Costikyan, "Traveller as Science Fantasy," The Space Gamer 49 (March 1982), pp. 8-9.

 

[EDG]

It hasn't spoiled my enjoyment of the game even a little bit.

You'll note that nobody claimed it would - but whether you enjoy it or not (or care about it or not) still doesn't change the fact that it's broken. If you don't care either way about it then you obviously have nothing to lose if it's fixed.