I've still got some wonky worlds in my sector

[Stattick]

Ok, so what atmo pressure is needed to maintain liquid on the surface? We've already established that an atmo of 0-1 won't cut it. What about very thin, pressure 0.1-0.42? Or thin, pressure 0.43-0.7?

Is it sufficient for the worlds w/ a low atmo pressure and with a hydro rating above 0 to be "Cold, -51 to 0 C", or should I put them at "Frozen, less then -51 C"?

 

[lastbesthope]

Don't know, but would depend on the liquid.

LBH

 

[EDG]

Ok, so what atmo pressure is needed to maintain liquid on the surface? We've already established that an atmo of 0-1 won't cut it. What about very thin, pressure 0.1-0.42? Or thin, pressure 0.43-0.7?

Is it sufficient for the worlds w/ a low atmo pressure and with a hydro rating above 0 to be "Cold, -51 to 0 C", or should I put them at "Frozen, less then -51 C"?

The diagram here might help:
http://www.lsbu.ac.uk/water/phase.html

1kPa = 0.01 atms
10 kPa = 0.1 atms
100 kPa = 1 atm
1 MPa = 10 atm
10 MPa = 100 atm

Cross reference the pressure with the temperature (along the bottom, in Kelvin: 273K = 0°C), and if your point is within the green area then it's liquid water under those conditions.

You'll note that under 1kPa, solid goes straight to gas form, so liquid water isn't stable under those pressures. The darker green area at high pressures and temperatures is where water is supercritical state, which is where the liquid and gas become indistinguishable from eachother.

 

[Stattick]

The diagram here might help:
http://www.lsbu.ac.uk/water/phase.html

1kPa = 0.01 atms
10 kPa = 0.1 atms
100 kPa = 1 atm
1 MPa = 10 atm
10 MPa = 100 atm

Cross reference the pressure with the temperature (along the bottom, in Kelvin: 273K = 0°C), and if your point is within the green area then it's liquid water under those conditions.

You'll note that under 1kPa, solid goes straight to gas form, so liquid water isn't stable under those pressures. The darker green area at high pressures and temperatures is where water is supercritical state, which is where the liquid and gas become indistinguishable from eachother.

Ok, so if I'm reading that correctly, there can be liquid water at right around 0.1 atm. At that pressure, there'd be just a tiny range where it would stay liquid before boiling off though. As the pressure rises toward 1 atm, the liquid range increases until we get what we have on Earth. It appears that the freezing point of the water doesn't change at terrestrial atm pressure levels though, just the boiling point. For any world that would ever even be considered to be colonized at any sort of tech that doesn't just seem magical, the freezing point of water will remain consistant, and the boiling point won't get dramatically higher then 100 C... otherwise the world would just be too pressurized to be inhabited without magi-tech.

So, in other words, no mods to world generation nessisary if the atm is rated 2+. Or did I fail my science roll?

 

[Gee4orce]

Here's my nomination for "Most Boring UPP" award, a world I genuinely rolled up:

X000000-0

an asteroid belt with no starport and no habitation. One wonders what it was exactly that made this world the nominated mainworld of the system...

 

[Supergamera]

Here's my nomination for "Most Boring UPP" award, a world I genuinely rolled up:

X000000-0

an asteroid belt with no starport and no habitation. One wonders what it was exactly that made this world the nominated mainworld of the system...

Maybe that's all there is in the system.

 

[phild]

Temperate is the AVERAGE temperature. The Moon is Temperate: Boiling during the day and Freezing at night, perfectly Temperate.

I don't think this is correct, although I have no evidence so shoot me down if you will! Temperate refers to climactic conditions, not purely temperature and certainly not to average temperature. Its meaning has a strong element of subjectivity, such that each world could well define its own temoerate as "the conditions under which native life prospers"! Online defintions I've just found include things like "Temperate climates are those without extremes of temperature and precipitation (rain and snow). The changes between summer and winter are generally invigorating without being frustratingly extreme."

Temperate, as a word, means moderate and not extreme.

 

[Solivagus]

Here's my nomination for "Most Boring UPP" award, a world I genuinely rolled up:

X000000-0

an asteroid belt with no starport and no habitation. One wonders what it was exactly that made this world the nominated mainworld of the system...

Maybe that's all there is in the system.

Yup, nothing in the system but a single barren asteroid that no-one wil ever want to visit.

It says so right there in the Imperium-approved star charts.

Ignore all rumours of top secret facilities dealing with relics of the Ancients or Things Man Was Not Meant To Know.. :twisted:

 

[EDG]

Temperate, as a word, means moderate and not extreme.

I'm sure one could class Earth as a Temperate world, but it's got ranges from Cold to Hot at least on it. Saying that a vacuum world is "temperate" just because the dayside is Hot and the nightside is Cold dilutes the information somewhat because it doesn't tell you that there is hot or cold areas there (which is why I proposed a separate code of "Extremes" for such worlds).

 

[EDG]

Ok, so if I'm reading that correctly, there can be liquid water at right around 0.1 atm. At that pressure, there'd be just a tiny range where it would stay liquid before boiling off though. As the pressure rises toward 1 atm, the liquid range increases until we get what we have on Earth. It appears that the freezing point of the water doesn't change at terrestrial atm pressure levels though, just the boiling point. For any world that would ever even be considered to be colonized at any sort of tech that doesn't just seem magical, the freezing point of water will remain consistant, and the boiling point won't get dramatically higher then 100 C... otherwise the world would just be too pressurized to be inhabited without magi-tech.

So, in other words, no mods to world generation nessisary if the atm is rated 2+. Or did I fail my science roll?

yes, but watch out for the thinner atms - if the pressure is low enough then you could get surface temperatures rising high enough (just from climate/latitude) to boil the oceans off!

 

[Rikki Tikki Traveller]

Temperate is the AVERAGE temperature. The Moon is Temperate: Boiling during the day and Freezing at night, perfectly Temperate.

I don't think this is correct, although I have no evidence so shoot me down if you will! Temperate refers to climactic conditions, not purely temperature and certainly not to average temperature. Its meaning has a strong element of subjectivity, such that each world could well define its own temoerate as "the conditions under which native life prospers"! Online defintions I've just found include things like "Temperate climates are those without extremes of temperature and precipitation (rain and snow). The changes between summer and winter are generally invigorating without being frustratingly extreme."

Temperate, as a word, means moderate and not extreme.

Well since you asked me too...

TMB page 174, RH gray box on temperature. The NOTE under Atm 0 or 1:

No modifiers, but temperature swings from roasting during the day to frozen at night.

That was added at the suggestion of our own EDG (the Planetologist).

Earth's Moon would qualify as "Temperate" using the Traveller scale, with Atmosphere 0 and a 28-day "day".

As was mentioned by others, Earth qualifies as Temperate, but there are sections of the planet that will be Hot or Cold or worse. The temperature of the world HAS to be an average or mean of some kind. There are too many variations in temperature on an entire planet to give it just a single temperature value.

 

[Stattick]

Ok, so I'm approaching completion of my sector generator, version 2. Rewritten from scratch.


X535678-5


This was one of the systems that would have been rolled via the Corebook, as a Temperate world. 50% of the surface covered in fluid, with a very thin atmosphere. Now, I'm just going with water here, since I know it best, but at that atmo pressure, the oceans boil off on a warm day, perhaps explosively. I really don't think that a temperate world would be able to retain that water for very long. The spreadsheet resets the "roll" in a case like this to a frozen or ice world. *nods*

I've also tweaked the minimal TL for conditions other then just the air. So no more TL 3 Roasting planets, or TL 1 water worlds/desert worlds...

I gave an additional +1 to the population of Garden worlds that don't have a tainted atmosphere. Dropped the max pop score down to 9, simply because I don't want to have sectors randomly populated with worlds that have a population of tens of billions (or more).

I wrote it up with the Hard Science rules.

There's only two problems right now. Too many X planets are generated, typically around 32%. And there's too many low population worlds generated too. I suppose that there could be some systems set up to populate themselves with frozen germ cells, or cloning, but if we're going with just standard reproductive methods, you'd need a population of 500 at the bare minimum to be viable for more then a few generations. From what I understand, a population of a 1000 is generally considered the lowest viable for vertebrates. So I need to figure out what I want to do with all of those low pop worlds generated by the hard science options... probably bump about half of them back up to the thousands, and the others can be newish colonies/short term corp ventures/abandoned/stranded/crazy cults/criminals/etc.

 

[EDG]

I really don't think that a temperate world would be able to retain that water for very long. The spreadsheet resets the "roll" in a case like this to a frozen or ice world. *nods*

I think that'll work better.

There's only two problems right now. Too many X planets are generated, typically around 32%. And there's too many low population worlds generated too.

To be clear, you're getting that many X starports with the Hard Science rules, right? So you're rolling 2d-7+population to get the starport? Because if you're not and you're still getting that many X starports then you're doing something wrong, because ordinarily you should only get X on a roll of 2 on your 2d roll.

So I need to figure out what I want to do with all of those low pop worlds generated by the hard science options... probably bump about half of them back up to the thousands, and the others can be newish colonies/short term corp ventures/abandoned/stranded/crazy cults/criminals/etc.

Yeah, the ones that aren't in the thousands would probably just be outposts, most likely not permanently staffed. Or they're short-term establishments.

 

[phild]

Earth's Moon would qualify as "Temperate" using the Traveller scale, with Atmosphere 0 and a 28-day "day".

As was mentioned by others, Earth qualifies as Temperate, but there are sections of the planet that will be Hot or Cold or worse. The temperature of the world HAS to be an average or mean of some kind. There are too many variations in temperature on an entire planet to give it just a single temperature value.

Ah, then my issue is with Traveller's classification. To qualify as temperate, strikes me it requires both a mean temperature in a certain range AND a variance on the mean within a certain range. And clearly, while the only measure of a planet's temperature is an average, the mode might well be a better climactic measure than the mean, as it will ignore violent extremes caused by atypical terrain like Antarctica or Death Valley.

 

[Stattick]

To be clear, you're getting that many X starports with the Hard Science rules, right? So you're rolling 2d-7+population to get the starport?

That's correct, I'm using the Hard Science rules. I need to experiment with it tommorrow, but I think I know how to fix it. See below.

There's only two problems right now. Too many X planets are generated, typically around 32%. And there's too many low population worlds generated too.

Yeah, the ones that aren't in the thousands would probably just be outposts, most likely not permanently staffed. Or they're short-term establishments.

I don't mind that there's some X starports, or even that there's some low population systems. However, what's bugging me is the high percentage of both (often on the same system). It also creates the further problem of breaking up the sectors even worse then standard system does. It makes it problematic and prohibitively expensive for any sort of trade to go on, especially with only a J1 or J2 ship. So the ships need to be hacked, or the sys-gen/hard science needs to be hacked.

I'll play with it once I get a chance and see what I come up with. I've got a few ideas perculating.

 

[EDG]

My solution to the starport problem was to roll d6 on different columns of a table defined the population ranges. So low pop worlds rolled between X-C, mid pop worlds (pop 4-6) were B-D, and high pop worlds (7 +) were A-C. And X starports were only allocated to populated worlds on GM discretion.

 

[Gee4orce]

There's only two problems right now. Too many X planets are generated, typically around 32%. And there's too many low population worlds generated too.

To be clear, you're getting that many X starports with the Hard Science rules, right? So you're rolling 2d-7+population to get the starport? Because if you're not and you're still getting that many X starports then you're doing something wrong, because ordinarily you should only get X on a roll of 2 on your 2d roll.

I noticed this too, with my world generator program I wrote, using the Hard SF rules: you get a LOT of X starport worlds. The reason for this, I think, is the population modifiers that are part of the hard SF rules which then compounds the fact that starport is rolled as 2d-7+pop.

That said though, 2d-7+pop makes more sense to me than having A or B class starports on uninhabited worlds (which happens under the standard rules)

 

[Stattick]

My solution to the starport problem was to roll d6 on different columns of a table defined the population ranges. So low pop worlds rolled between X-C, mid pop worlds (pop 4-6) were B-D, and high pop worlds (7 +) were A-C. And X starports were only allocated to populated worlds on GM discretion.

Hmm....

I'll have to take a look at that. That might work better and simpler then the hack I was thinking about. I was thinking of divorcing the starport and population DMs from the TL roll, modding the TL roll, and rolling that before the starport. Then rolling 2d6-7+((pop+TL)/2). I'm not at home, so I haven't had a chance to play with the spreadsheet yet.

I understand why they went the way they did, but pop+TL would be a logical way for the Imperium to decide where to put their starports. So the two are still tied together, but backwards from the book. EDG's way might be better though. Will play later, and report back.

 

[EDG]

Either that or say that the starport is E down to a roll of -2 using hard science rules, and it's X below that? (the minimum possible result would be -4: a roll of 2, subtract 7, add pop 1 = -4. That's assuming that pop 0 = starport X automatically).

 

[Rikki Tikki Traveller]

My suggestion on the starports is to make any roll of less than 2 be an E rather than an X starport.

X starports should be rare, even using HS unless there are no people.

If there are even just a couple dozen people, there is going to be a bare spot with a search light or a landing beacon, either of which would qualify it as an E starport.