System Generation Problem?

[Fritz_Brown]

A question on stellar luminosity in WBH. The numbers don't mesh with the numbers in LBB6 at all. A few examples:

Star	LBB6	WBH
B0 Ia	560,000	27.36
G5 III	75	2.94
M9 II	16,200	11.28

LBB6 says

Luminosity is derived from magnitude, but expresses it in terms of Sol. Thus, a star which has a luminosity 2 is twice as bright as the sun.

WBH says

.

So, what unit is used in the WBH table? And, of course, the formulas for base temperature are totally different.

 

[Fritz_Brown]

Also, how do I interpolate from stellar code 5 to 9? 0 to 5 is easy if I assume it's linear. But I know it's not a progression from, say, A9 to F0, s I can't interpolate using A5 as one end of a linear progression and F0 as the other. It seems that just carrying the math through from the A0 to A5 progression doesn't necessarily work, either. What to do?

 

[Frankymole]

You have absolutely no idea how disheartening it is to hear that there never were any improvements between Book 6 and now.

I have reviewed Grand Census/Grand Survey, and the World Tamer's Handbook, and cannot locate anything. I know I have the World Builder's Handbook somewhere, but can't find it at the moment.

Does Mongoose Traveller offer an improvement in one of it's supplements?


I disagree with that.

If it were true, it would be the same as stating that they were guaranteeing that they never wanted 99% of players to use their system generation process more than one or two times.

It is lengthy and tedious to go through the process by hand, and its rules are incomplete, requiring personal interpretation as to what to do, making it certain that precisely the same set of rolls are very unlikely to ever be handled the same way twice.

Indeed, if it were only to be used once or twice, then its overall quality and correctness would not matter.

However, for those who actually want to use it a lot, as in tens of thousands of times*, the only way to go is automation via computer programming.

The current rules as given cannot be programmed for automation because they are incorrect. They are incorrect because they cannot be followed except by personal interpretation. Any attempt to codify personal interpretations into a computer application automatically renders it non-canon and therefore of limited interest to many.

"Is your software's output canonical?"
"The Book 6 rules aren't complete and correct, so personal interpretation was required to complete the software."
"So, not canonical?"
"There is no canonical!"
"Oh. Thanks for your efforts."
Downloads: 0

Well, even Heaven and Earth wasn't canonical, since it reversed the planet size-1D formula for determining satellite size.

 

[fridge]

A question on stellar luminosity in WBH. The numbers don't mesh with the numbers in LBB6 at all. A few examples:

Star	LBB6	WBH
B0 Ia	560,000	27.36
G5 III	75	2.94
M9 II	16,200	11.28

LBB6 says

WBH says


So, what unit is used in the WBH table? And, of course, the formulas for base temperature are totally different.

When WBH was written, the math was simplified by rolling in a number of constants into some of the look up values, and modifying the actual formula to not have the constants show, or have simpler constants show. Stellar Luminosity is one of the variable that had this applied.

 

[Fritz_Brown]

That makes sense, Fridge. Thank you. So, I can apply the tables and formulas from LBB6 and get the same results as the tables and formulas from WBH - that works for me.

Any idea on the interpolation thing? (Would have been so much easier to give a value for the "9"s in each spectral class, even if they weren't on the table for initial rolling.)

 

[fridge]

That makes sense, Fridge. Thank you. So, I can apply the tables and formulas from LBB6 and get the same results as the tables and formulas from WBH - that works for me.

Any idea on the interpolation thing? (Would have been so much easier to give a value for the "9"s in each spectral class, even if they weren't on the table for initial rolling.)

Use the 0 from the next star, eg to work out G9 V use the G5 V and K0 V values and extrapolate from there.

Stars are not that precise anyway, each is individual. You could safely have a 10% swing each way on Luminosity or Mass without breaking anything.

 

[Fritz_Brown]

Use the 0 from the next star, eg to work out G9 V use the G5 V and K0 V values and extrapolate from there.

Except that some of the values actually go *down* for the next spectral class. Luminosity is definitely not a linear progression from B to A to F to....

 

[Fritz_Brown]

Yep, interpolating gets me a negative luminosity in one instance. There has to be a better set of data from which to interpolate. Anyone know where it is? If I could tell which bit was which on the Wikipedia chart about spectral class, I might be able to figure something out.

 

[fridge]

Yep, interpolating gets me a negative luminosity in one instance. There has to be a better set of data from which to interpolate. Anyone know where it is? If I could tell which bit was which on the Wikipedia chart about spectral class, I might be able to figure something out.

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The problem is too many tables of luminosities, which don’t match each other. Mostly they give every fifth point (A0, A5, F0, F5, G0 etc), and interpolation is legitimate. The problems come from different stars of the same colour/temperature having different Lum (eg Sol and Alpha Cen A both G2 V, Alpha Cen A has 1.6 times Solar Lum), often due to different ages, so different tables based on different observation sets have different values (and some sources round off differently, some are based on simplifications of rounded off sources, some have typos, etc).

If the set of data you are using kicks back up when extrapolating, and you get a negative, just reverse the sign. The kick back up happens somewhere between the points you have.

 

[Fritz_Brown]

It's the published data in LBB6 and WBH. I do see where real data should be a continuum from B0 to M9. The Traveller stuff has me befuddled. I'll keep at it... maybe it will work itself out.

 

[Fritz_Brown]

OK, slightly different question. From the WBH, there is a table for "Latitude temperature modifiers" which gives the temperature difference (from the base) based on the hex row for a certain size planet. However, there isn't a column for size "S". What to do?

 

[Frankymole]

OK, slightly different question. From the WBH, there is a table for "Latitude temperature modifiers" which gives the temperature difference (from the base) based on the hex row for a certain size planet. However, there isn't a column for size "S". What to do?

I used size 1.

Though now I play with modified world hex maps using suggestions from the original JTAS, so the number of hex sides per triangle side is equal to world size. The WBH tables don't work with those.

 

[Fritz_Brown]

I'm not necessarily using the world hex maps. I'm simply using the maximum on each end to help determine the maximum increase and decrease. Perhaps I should just use a set number - should it be close to 0?

 

[Shonner]

T5 counts the edges of hexes along a triangle edge now, rather than counting their centers as previously done, for world size maps.