[Space] How habitable is my universe?

[Agemegos]

This project is in abeyance

[thrash]

First response is, what happened to Habitability 7-8? Did you really not have even 0.1% of systems with worlds of Standard or Dense (but not Marginal) atmosphere, hydrographic 60-90%, and Chilly, Cool, Normal, Warm, or Tropical climate? Given that you report 10.5% with Habitability 2-6, I find this hard to believe. Earth is Habitability 8, not 7 -- did you miss the +1 for non-Marginal atmospheres?

Second answer is, look at the Affinity Modifiers Table on p. 91. RVM averages to 0, so on average Affinity is equal to Habitability. All other things being equal, a world with Habitability 8 (like Earth) can support ~62.5 times as many people as one with Habitability 2. You could interpret this several ways, depending on the specifics:

* Only 1.6% as much land is actually habitable (mountain-tops, polar islands, microclimates)

* Only 1.6% of the potential population is able to adapt to conditions, either physically or culturally

* The land surface as a whole is only 1.6% as productive.

The actual answer is probably some combination which results in 1.6%, e.g. 10% of the land is habitable, 40% of the population can adapt, but the land is only 40% as productive.

[TheDS]

He only ran it 200 times; 0.5% is the increment for that.

Let me also suggest to Agemegos: If you can arrange your data into a more manageable format - when I did a sheet for First In world and system generation, I made it a point to put all my system data (minus world and moon data) into a single column, allowing me to easily grab the data and copy it where I wanted, or even generate numerous systems at once by grabbing the handle and dragging it over until I had as many columns as I wanted.

So my advice to you is, put your data into a single column (or row), then select it all and do a massive copy and paste (should take about 3 seconds). Then you can generate data for up to about 250 systems at a time (or 65000 if you go for rows). Your final columns (or rows) will be to count up each result. A simple average is easy to find, but if you wanna know the numbers, you'll have to use something like the COUNTIF function, and may need numerous additional columns.

But with judicious use of copy/paste and some thought about how to count up the results, you could probably generate 10,000 systems at a time (for data-mining purposes, as you did above) with a LOT less total effort and time spent.

[TheDS]

I am also wondering why there wsn't more of a curve in the results, with low-hab worlds being more numerous, but I suppose you may have manually adjusted the curve so we weren't wasting so much time on crap worlds. (I don't have the new Space yet.)

[David Johnston]

Originally Posted by Agemegos

Which leads me to a question.

I have no real feel for the GURPS Space scale of habitability. Earth is a 7. 0 means that you die in minutes without TL7 or better breathing gear. How bad is a 2?

You probably die just as fast. Habitability 2 worlds are probably worlds with Suffocating atmospheres and oceans. However they are worlds where you can introduce plantlife that can survive without much help which helps provide food for your domes.

[TheDS]

My second post was more directed at Thrash (or whoever wrote the book), since he's the one responsible for the formulae and their results.

And my suggestion for your data management whatever was purely for the purpose of selecting everything at once and drag-pasting so you could perform your calculations 100-10,000 times at once, purely for the purposes of getting a larger sample of hab distribution data. You wasted an hour or so running your sheet 200 times, when you could have made the computer do the work for you.

I'm NOT saying you should make that your distribution; who really wants to generate that many systems at once?

[Anders]

Probably many M0 or dimmer stars. I suggest you add an option to generate habitable star systems, as per p.101...

[Pomphis]

Looking at Space p.88 I think we can say:

Any world with an acceptable atmosphere (standard or dense, non-marginal)and temperatures between Chilly and Tropical is 6+.
Cold or Hot reduces this by 1.
OTOH any hydrographic percentage from 1-99% is +1 or +2.

So roughly earthlike worlds will be at 6-8. 5 will be a marginal case, I guess at best as habitable as alaska or australian deserts. After all, the atmosphere alone gives us 4, and 5 means either 1-99% Hydrographics plus Very Cold or Very Hot (or worse), or 0% or 100% Hydrographics plus Cold or Hot. 4 or less means serious problems with the atmosphere and/or extreme temperatures.

Then again, these are planetary averages. A 5 might have an acceptable atmosphere plus 91% Hydrographics plus Very Cold, with the 10% land at the equator being significantly warmer than the average, or Very Hot, with the 10% land at the poles being significantly cooler than the average.I assume this is unlikely, so only a small percentage of 5´s will be reasonably habitable.

[thrash]

Originally Posted by Agemegos

The sample was only 200. Those figures are good to 0.5%, not 0.1%. And even that is subject to sampling deviation.

Need to pay more attention, obviously. I tend to approach the problem analytically, by working through the probabilities, rather than empirically.

What are your own results?

http://www.io.com/~thrash/firstin.html

The procedure in GT: First In is conceptually similar to GURPS Space 4/e. The key observation is that the definition of "habitable" is based on Earth, so each characteristic forms a distribution around that central value. It may be a tailed distribution (e.g., because atmospheric density is correlated with size), but over a large enough sample the combination should be a bell curve with a peak in the mid-range (maybe 6-7?).

I understand that. I'm trying to get a qualitative feel of how forbidding conditions are. When it comes to generating my universe I will need to know which planets people will go to and which are just too unattractive, given that travel is expensive and one-way... I don't think people would go to settle a 1.

Ideal population distribution is a function of diffusion and affinity: people spread out as far as possible, consistent with the resources available.

The simplest method is to take the figures at face value, calculate carrying capacity directly, divide by transportation costs, and distribute population (or at least, initial colonies) proportionately. There are very few places on Earth so harsh that no one has ever settled there; even places like Antarctica might have been settled by Inuit-analogs, if (e.g.) the process of Polynesian expansion had continued for a few thousand years. Habitable planets are similar: that breathable atmosphere is a huge advantage.

[TheDS]

Well, if it's a system sheet, you need system data. The central star's characteristics, if it has companions, then you need their characteristics and orbital info. Then you need to know orbital slot info (forbidden zones, snow limit, hab zone, orbit slot distances, etc).

That right there is a lot of information, about 20-40 pieces of data (iirc from when I did this for First In).

Are you talking about developing and displaying planetary information for each object in an orbital slot (including moons)? Each body is going to need around 20-60 pieces of information (more if it's habitable and has its own life, less if it's just a belt or giant) all on its own, which you're obviously wanting to put most of it on a seperate detail sheet, but each piece of into you want on the system sheet, that's a lot of extra info to add to it. Are you making a graphical display?

What i'm getting at is: don't go overboard. You've got the right idea to only want to display the most important information, but you've listed a lot of things that really don't need to be put on the system sheet. I'd guess at most you'd put the World type and Hab rating (I'd also put blackbody, because I'm awesome/weird like that). Maybe orbit characteristics (orbit time, eccentricity, inclination, perigee point, current position) because it affects how the system is drawn graphically, in case someone wants to do that. Anything else is really just world detail.

Color-coding for Hab would be neat, as would having a particular graphic for each world type.