GURPS SPACE and placing orbits

[hal]

Originally Posted by Humabout

Ah so you are trying to limit the randomness in his random generator. That's why you are running into issues. That you can generate subgiant, giant, or dwarf stars is hardly a problem. All of these star types exist, so the chance of generating them should, too. The problem lies in wanting specific conditions in your system.

Just so you get a better picture...

Because I know what I'm doing in the background, I know how to make it so that if I want to set parameters ahead of the random generator process, all I have to do is set up a Boolean switch where I use the line...

"If RandomWorldType then gblWorldType = GetWorldType()"

Otherwise, I simply grab the value off the Parameter dialog page and we're good to go.

A strictly random star system generator will allow for close binary pairs that would (per the rules) outlaw worlds in forbidden zones. Since TRAVELLER postulates that every star system has a main world, that automatically means that any use of GURPS SPACE to generate Spinward Marches star system data, would have to insure that none of the main world orbits are forbidden zones. Easy peasy. Just set a parameter that says "NoForbiddenMainWorldZones" and override any random generation of the star system that permits it. ;)

So, removing SOME of the random aspects isn't all too difficult. Figuring out the more efficient manner in doing it, that's half the fun.

[hal]

OK - now I'm running into a problem of sorts based on the process I'm following...

In placing the orbits, the question was "wouldn't it be better to simply place the main world first, then all others. Now a problem of sorts has reared its ugly head.

Simply stated: Epistellar Gas Giants. They can violate the inner limit rule. Question now becomes...

Is there any reason they can't also violate the .15 AU distance to nearest neighbor rule?

If I still have to adhere to the .15 orbit separation rule, then instead of having the Loop process until current orbit - .15 < Inner Limit, I simply institute the Epistellar Orbit as the new Inner orbit limit and place orbits that way.

Just curious.

[AlexanderHowl]

Honestly, the 0.15 AU rule is unrealistic from everything we see for exoplanets.

[hal]

Originally Posted by AlexanderHowl

Honestly, the 0.15 AU rule is unrealistic from everything we see for exoplanets.

Question?

Back in my high school days (yeah yeah yeah, when the Dinosaurs walked the earth... :P) We were taught that our measurements were going to be within an error rate of +/- some value just due to the accuracy possible with the measuring instruments.

Are the instruments being used to measure orbital distances for exo-planets such that a difference of .05 AU is within the realm of error for the measuring instruments? Just curios.

[Flyndaran]

Originally Posted by AlexanderHowl

Honestly, the 0.15 AU rule is unrealistic from everything we see for exoplanets.

The more we learn, the more it seems like rules were guidelines, and guidelines were assumptions. Other than that odd gap in planetary sizes between mega-Earths and Neptune, star systems have far less order than we ever imagined.

Crazy for astronomy, but liberating for GMs.


We may have just found a Neptune sized moon orbiting a Jupiter plus sized planet.

[AlexanderHowl]

We have exoplanet systems where the planets are separated by 0.005 AU, which is much close than the 0.15 AU exclusion given in Space.

[johndallman]

Originally Posted by AlexanderHowl

We have exoplanet systems where the planets are separated by 0.005 AU ...

Which suggests to me that our solar system may be freakish in its wide separations, and consequent lack of major collisions.

[AlexanderHowl]

Which is a good point, though we may only be seeing the extremes because those are the easiest systems to observe with contemporary technology. We would be hard pressed to detect a system like ours right now, though that will likely change over the next couple of decades.

[Varyon]

Originally Posted by AlexanderHowl

Honestly, the 0.15 AU rule is unrealistic from everything we see for exoplanets.

Of course, a stable orbit probably can’t pass as close to a gas giant as it can a terrestrial planet, as the former has a lot more mass (and thus a larger gravitational footprint). Do we see any cases of exoplanets where there’s less than a 0.15 AU separation when a gas giant is involved?

[Anthony]

Originally Posted by johndallman

Which suggests to me that our solar system may be freakish in its wide separations, and consequent lack of major collisions.

Eh. The problem is that the minimum separation should be a function of the distance to the primary (say, 15% instead of 0.15). We have enough moon systems to look at that we can be pretty confident about gravitational interactions creating excluded zones, but it's based on masses and orbital ratios, not absolute differences.