[Space] example system stats

[Prime Evil]

Originally Posted by Brett

Thank you. I'm sorry to disappoint, but those were produced by hand, not randomly generated.

Pity. They are very nice and you deserve kudos for them. I think they strike a good balance between too little detail and too much.

Originally Posted by Brett

Again I'm sorry to disappoint. It was because of the difficulty of handling tweaks-to-setting that I chose not to implement any society-generation. I made the social data in the third post by combining some of the data from the spreadsheet that generates my own setting, and using some parts of the 'Generating a [Planetary] Society' sequence out of an old SF game called ForeSight, and tweaking, rearranging, and amplifying the results by hand.

Heh. I think that I've got a copy of ForeSight lying around somewhere, but I haven't looked at it in years. My own campaign borrows some ideas from the old FGU Space Opera game.

Originally Posted by Brett

That much is a very faithful instantiation of the sequence in GURPS Space. But as it happens that instance is not randomly generated, it consists of real data for the system CD -25°1169. However this was fed in as input to the workbook through its provisions for designing or partly-designing a world, not faked over the output afterwards.

I can see that you follow the world generation sequence in GURPS Space faithfully even though I haven't checked the maths. Automating the advanced worldbuilding sequence is still an impressive feat. :)

Originally Posted by Brett

In principle very easy, but with one huge snag. You would put your star-list in to an extra sheet in the workbook, and then use the system number as the index to LOOKUP statements in the input fields.

Interesting. At least your spreadsheet supports this kind of customization. Very cool.

Originally Posted by Brett

The huge snag is that catalogue data do not include the ages and masses of the stars, or at least not very many of them. And the GURPS Space starsystem generation sequence takes those figures as its starting-point. You can estimate mass from spectral class, though unfortunately the sequence doesn't treat masses corresponding to some spectral classes. Then you come across the point that led to my giving up on that project: when you try to estimate age from spectral class and luminosity you come across a great many starts that are either too bright or two dim for that to work. I don't know why. It could be the result of errors in measurement: stellar distances are not known with great precision, and neither are apparent magnitudes and colour indexes.

I've stumbled across the same issue when trying to design the nearby systems by hand. Fortunately, there are a number of astronomy websites that provide rough estimates for the mass and age of stars in our immediate neighborhood, but in many cases these are nothing more than informed guesswork. I ended up assembling a spreadsheet collating information on the stars in a 100 ly radius from various sources and then making my own judgment calls where necessary. The imprecision of measurements over astronomical distances can be sometimes be a good thing, providing a fudge factor that can be tweaked to generate a variety of outcomes.

Originally Posted by Brett

Then there is a lesser snag in that some of the tables in the GURPS Space starsystem generation sequence might need substantial tweaks to produce the kind of universe you have in mind for your campaign.

True. But when using an automated tool, it's possible to modify the tables to ensure that you generate exactly what you want.