The World Builder's Handbook - It Is Here!

[Geir]

A news article on the structure of the Sol solar system. Secret "Symmetries"

*blink, blink*
Well, the Live Science article provides nothing actionable. And the actual paper... would probably require a math PhD to determine if further study of it would provide anything actionable (like dependences between eccentricities and orbital, location, planetary mass, etc.) Or I could just throw dice...

 

[Arkathan]

Might just be bad luck on my part, but I've never had Traveller worlds generate a system that I'd actually want to use. Which is probably just the nature of random, it doesn't have any means of selecting for interesting.

That's where "Insert object(s) here" comes in handy. The random is for everything else.

 

[Dalton Calford]

Hey Geir,

What source did you use for your radius, temperature, and mass calculations for the various star types?
I am finding that some of the numbers in your list don't match up with the sources in either the online stellar databases or various university online resources. I did not see which sources you cited in your work.
Don't get me wrong; your work is amazing, but I just want to confirm the numbers are correct before hard copies are printed.
I am specifically reviewing your tables on page 17 (Star Mass and Temperature by Class); page 19 (diameter and luminosity by class)

best regards
Dalton

 

[Geir]

Hey Geir,

What source did you use for your radius, temperature, and mass calculations for the various star types?
I am finding that some of the numbers in your list don't match up with the sources in either the online stellar databases or various university online resources. I did not see which sources you cited in your work.
Don't get me wrong; your work is amazing, but I just want to confirm the numbers are correct before hard copies are printed.
I am specifically reviewing your tables on page 17 (Star Mass and Temperature by Class); page 19 (diameter and luminosity by class)

best regards
Dalton

You'll probably not care for my methodology, but it went like this:
I started with the old WBH table, corrected the ones that were obviously wrong, then spot-checked with stars that matched the cell (Found a B5 III, for instance) using mostly Wikipedia, sometimes SIMBAD - both sources rather incomplete, SIMBAD sometimes overly complete and competing... and then did some rounding to one or two significant digits.

That being said, sometimes it was just making the 'curve' of numbers look about right, so if there are specific issues, yes, let's fix them.

 

[Dalton Calford]

You'll probably not care for my methodology, but it went like this:
I started with the old WBH table, corrected the ones that were obviously wrong, then spot-checked with stars that matched the cell (Found a B5 III, for instance) using mostly Wikipedia, sometimes SIMBAD - both sources rather incomplete, SIMBAD sometimes overly complete and competing... and then did some rounding to one or two significant digits.

That being said, sometimes it was just making the 'curve' of numbers look about right, so if there are specific issues, yes, let's fix them.

I can provide actual numbers for you, with cited sources if that would be of any help.

A great source is

Stellar Spectral Classification

Written by leading experts in the field, Stellar Spectral Classification is the only book to comprehensively discuss both the foundations and most up-to-date techniques of MK and other spectral classification systems. Definitive and encyclopedic, the book introduces the astrophysics of...

books.google.ca

I have the following information

Class Sub Class Decimal Classification Luminosity ie M2 V
Mass (sol=1)
Luminosity Lstar/Lsun
Radius Rstar/Rsun
Radius in AU
Radius in KM
Temp K
Color Index B-V
Abs Mag Mv
Bolo Corr BC(Temp)
Bolo Mag Mbol
Red Green Blue (RGB values)

For CLASS Types OBAFGKM as well as CNRSW(C and N) and D(A, B, C, O, Q, and Z)
Including all decimal classifications from 0-9 where applicable.

There are other sources as well, mostly university texts.
If you grab a few simple numbers from the list, but provide the whole list as a spreadsheet (for those geeks like myself who love the details)

Let me know if that is the sort of thing you are interested in.

 

[Geir]

I can provide actual numbers for you, with cited sources if that would be of any help.

A great source is

Stellar Spectral Classification

Written by leading experts in the field, Stellar Spectral Classification is the only book to comprehensively discuss both the foundations and most up-to-date techniques of MK and other spectral classification systems. Definitive and encyclopedic, the book introduces the astrophysics of...

books.google.ca

I have the following information

Class Sub Class Decimal Classification Luminosity ie M2 V
Mass (sol=1)
Luminosity Lstar/Lsun
Radius Rstar/Rsun
Radius in AU
Radius in KM
Temp K
Color Index B-V
Abs Mag Mv
Bolo Corr BC(Temp)
Bolo Mag Mbol
Red Green Blue (RGB values)

For CLASS Types OBAFGKM as well as CNRSW(C and N) and D(A, B, C, O, Q, and Z)
Including all decimal classifications from 0-9 where applicable.

There are other sources as well, mostly university texts.
If you grab a few simple numbers from the list, but provide the whole list as a spreadsheet (for those geeks like myself who love the details)

Let me know if that is the sort of thing you are interested in.

That's probably too much detail for Traveller. I've 'edited out' the most complex (also rare) case like carbon stars and Wolf-Rayet stars and white dwarfs are greatly simplified with no distinction by type, just by age.

I can probably find at least one example showing every number for mass on page 17 is wrong - stars are going to change temperature and luminosity over the course of their lifetimes and metallicity will impact these characteristics as well.

I am concerned if certain values are completely outside the bounds of examples or so far off at a tail of accepted values that randomization won't even get you back to the mean value, but that's the level of detail required. Mass especially can be tricky, because it is in one way or another an indirect measurement. For single stars it is a complete guess (okay, that's not fair, but let's call it a theoretical value), for binaries and multi-star systems the values can be determined better if we have a long enough observation time to figure out the orbital parameters, but even then, that's based on an accurate estimate of their distance. Gaia is providing better parallax, but at the cost of so much data an AI will need to sort it all out.

Also, most stars are going to be main sequence M, K, or G - and even there the standard method in the book skews too heavily away from M (it's noted on page 16, so you can adjust for your own universe to be more 'realistic'). If the numbers for main sequence stars are wrong, then that's pretty serious. If the numbers for, for example, a B1 Ib are a little wonky, it might never happen randomly and even if it did, we're looking at a star orbited by protoplanetary rocks and a lot of dust and gas. Still if something is clearly wrong, I'd want it fixed.

 

[ProfGrizzlyJon]

So angry at you @Geir; thanks to your phenomenal work, I am having to revise my (now) sub-par supplement on the Volya Collective and their quirk-ridden Zerkalo-class starships. It serves me right for creating something designed to operate in “empty hexes”

Seriously, though- fantastic work.

 

[Dalton Calford]

That's probably too much detail for Traveller. I've 'edited out' the most complex (also rare) case like carbon stars and Wolf-Rayet stars and white dwarfs are greatly simplified with no distinction by type, just by age.

I can probably find at least one example showing every number for mass on page 17 is wrong - stars are going to change temperature and luminosity over the course of their lifetimes and metallicity will impact these characteristics as well.

I am concerned if certain values are completely outside the bounds of examples or so far off at a tail of accepted values that randomization won't even get you back to the mean value, but that's the level of detail required. Mass especially can be tricky, because it is in one way or another an indirect measurement. For single stars it is a complete guess (okay, that's not fair, but let's call it a theoretical value), for binaries and multi-star systems the values can be determined better if we have a long enough observation time to figure out the orbital parameters, but even then, that's based on an accurate estimate of their distance. Gaia is providing better parallax, but at the cost of so much data an AI will need to sort it all out.

Also, most stars are going to be main sequence M, K, or G - and even there the standard method in the book skews too heavily away from M (it's noted on page 16, so you can adjust for your own universe to be more 'realistic'). If the numbers for main sequence stars are wrong, then that's pretty serious. If the numbers for, for example, a B1 Ib are a little wonky, it might never happen randomly and even if it did, we're looking at a star orbited by protoplanetary rocks and a lot of dust and gas. Still if something is clearly wrong, I'd want it fixed.

No worries, I may publish it with all the extended details so that people can use it in software or in their own campaigns.

For role-playing, you can have direct game effects based upon stellar wind and worlds that are kept to a lower tech level due to constant stellar storms, or you can have a radiation effect just for being in the system.

Magnetic bubbles generated by fusion reactors, to protect from the local solar effects, having "human like" flora/fauna within them while native life flourishes in their natural high rad environments.

This can affect the chances for life, affect trade effects, etc.

The key is a way of converting the numbers into something a referee can use as flavour text. The Explanator software is a good example of such a thing. I will need to do up a "game effects" description for each star/sun.

You have created such a masterpiece with this book, regardless of the many elements in your design sequence that are wrong on a real-world basis. For example, look for novenary (9 star) systems but the odds are so low that there are only 3 such systems listed in the databases to date. I don't blame you for making such a choice - I could not for the life of me figure out how to work out the various odds on D6 to match up with a realistic distribution of star types. I also limited my calculations within 1000pc of Sol, as that is a tiny cross section of the sub-arm that we are in.

So I can see why you limited it and I can see the issues you had to deal with, but, I have to disagree with not making the actual numbers available and having a mechanical way of describing what they mean. The beauty of Traveller is that you can add/use rules and mechanics as you wish, or they can be ignored.

Anyways, let me know if you want the charts/materials. I also have the entire TravellerMap for 1105 in a spreadsheet if you want it.

Best regards
Dalton

 

[Geir]

No worries, I may publish it with all the extended details so that people can use it in software or in their own campaigns.

For role-playing, you can have direct game effects based upon stellar wind and worlds that are kept to a lower tech level due to constant stellar storms, or you can have a radiation effect just for being in the system.

There certainly can be more effects from radiation based on the system. In Traveller, you get a blanket 500 rad protection on starship and there is no accounting for the accumulation of low-level background radiation, but it definitely is something to add a a detail for specific worlds. For events on custom encounter tables.

Magnetic bubbles generated by fusion reactors, to protect from the local solar effects, having "human like" flora/fauna within them while native life flourishes in their natural high rad environments.

This can affect the chances for life, affect trade effects, etc.

The key is a way of converting the numbers into something a referee can use as flavour text. The Explanator software is a good example of such a thing. I will need to do up a "game effects" description for each star/sun.

For example, look for novenary (9 star) systems but the odds are so low that there are only 3 such systems listed in the databases to date.

Really? Not that I don't believe you, but when I searched a while back, I found 3 sevens and 0 eights. You sure those nines aren't line-of-sight listings? In any case, I decided to base the multi-star model on T5's primary-centric model, which only allows for up to eight and is not exactly real world. The real world model would look more like a branching tree, and could be arbitrarily large, but I went for compatibility instead.

I don't blame you for making such a choice - I could not for the life of me figure out how to work out the various odds on D6 to match up with a realistic distribution of star types. I also limited my calculations within 1000pc of Sol, as that is a tiny cross section of the sub-arm that we are in.

This is where d100s or even d1000s come in handy... of course, if you want realism, you'd also need to go 3D. 2300 does that, but unfortunately for continuity purposes they use locations, characteristics, and names from the mid 1980s - I understand why, but it might might be time to look at a more 'modern' look at our local stellar environment. A new game, one that is not so... (okay, I know I'll get crap about this) French.

So I can see why you limited it and I can see the issues you had to deal with, but, I have to disagree with not making the actual numbers available and having a mechanical way of describing what they mean. The beauty of Traveller is that you can add/use rules and mechanics as you wish, or they can be ignored.

Definitely. The Referee and gaming group has that option. Me, as a writer for an established game, I have to color mostly within the lines.

Anyways, let me know if you want the charts/materials. I also have the entire TravellerMap for 1105 in a spreadsheet if you want it.

I've got all the sectors I'm currently working on. There's a way to get most, if not all of the data, directly by API or from GitHub, but I haven't messed with it.

Best regards
Dalton

Thanks for your comments!

 

[Dalton Calford]

This is where d100s or even d1000s come in handy... of course, if you want realism, you'd also need to go 3D. 2300 does that,

Did you ever read my article on Stellar Cartography in JTAS 7?

I am not a writer, but math, well, that is my passion. The whole design is based upon known mathamatical processes although I could have filled a few books trying to explain it to non-math nerds. But, the basic premise is that the hex map is 3d but is a map projection in the same manner that we map a 3d globe onto a 2d map. Each hex is a cubic parsec with the six sides of the cube, matching to the six sides of the hexagon. So a system is 3.26ly by 3.26ly by 3.26ly or 34.64 cubic light years. More than enough for two or more systems by your definition and fits within the lines of the existing material. All the mapping is relative and the placement of the outer hexagons change depending on some very complex formulas but you can do a 1:1 mapping from realspace to a hex map and back, but, you can not map a random hex map onto 3d due to the way systems can appear onto the map in a manner that is impossible in 3d (it would take a few pages of text and diagrams to explain why).

Definitely. The Referee and gaming group has that option. Me, as a writer for an established game, I have to color mostly within the lines.

I've got all the sectors I'm currently working on. There's a way to get most, if not all of the data, directly by API or from GitHub, but I haven't messed with it.

Thanks for your comments!

The api gives back inconsistent information depending on the original source document, so it takes quite a bit of data manipulation to get it all to line up properly in a spreadsheet. But then, you need to extract out the various blocks of information into separate columns, i.e., split the population from a UWP and convert it from ehex to decimal.
It's a great deal of work. I am using a combination of your system and mine to detail all the sectors from -18x to +18x and +18y to -18y, as well as using updated explanator software to create details for them all.
I am about a year into the project, but when complete, I should have a full system setup for people to use and add to. Something with a bit more detail than what is currently on TravelerMap, but without the wiki spoilers from later time periods

 

[Geir]

Did you ever read my article on Stellar Cartography in JTAS 7?

I am not a writer, but math, well, that is my passion. The whole design is based upon known mathamatical processes although I could have filled a few books trying to explain it to non-math nerds. But, the basic premise is that the hex map is 3d but is a map projection in the same manner that we map a 3d globe onto a 2d map. Each hex is a cubic parsec with the six sides of the cube, matching to the six sides of the hexagon. So a system is 3.26ly by 3.26ly by 3.26ly or 34.64 cubic light years. More than enough for two or more systems by your definition and fits within the lines of the existing material. All the mapping is relative and the placement of the outer hexagons change depending on some very complex formulas but you can do a 1:1 mapping from realspace to a hex map and back, but, you can not map a random hex map onto 3d due to the way systems can appear onto the map in a manner that is impossible in 3d (it would take a few pages of text and diagrams to explain why).

I did read that article and I thought it was great. I scrawled an attempt to implement it for something entirely unrelated (at least to any published material), but... okay, we won't veer of into math that will probably be entirely beyond me, but I can see how it works for a seven hex cluster - what in the ancient days of Metagaming was called a 'megahex' - and how you could make it work for a megahex and the surrounding six megahexes, but eventually I think you would still run into what I crudely call the 'splayed fish problem' (that analogy works in my head, I won't try to explain it - maybe I'm just a bad fisherman, or bad at preparing my catch) - eventually two systems very close together will end up on the opposite sides of the map. To my oversimplified imagination, this comes back to the holographic principle: you might be able to map a 3D space onto a 2D sphere, but you can't map it onto a 2D plane.

 

[Dalton Calford]

I did read that article and I thought it was great. I scrawled an attempt to implement it for something entirely unrelated (at least to any published material), but... okay, we won't veer of into math that will probably be entirely beyond me, but I can see how it works for a seven hex cluster - what in the ancient days of Metagaming was called a 'megahex' - and how you could make it work for a megahex and the surrounding six megahexes, but eventually I think you would still run into what I crudely call the 'splayed fish problem' (that analogy works in my head, I won't try to explain it - maybe I'm just a bad fisherman, or bad at preparing my catch) - eventually two systems very close together will end up on the opposite sides of the map. To my oversimplified imagination, this comes back to the holographic principle: you might be able to map a 3D space onto a 2D sphere, but you can't map it onto a 2D plane.

The best way to consider it is a bump map, the key to how it works together, was in the extra 10 or so pages that hit the editing room floor but if you look at the 26 possible directions, you will see that their are far more hexes than 27 within the 3 rings around the central hex.
So, you need to know that the outer hex placement moves and it fits an einstein graph of tessilation, which is actually slightly non-aligning to the hexagonal shape you see (almost forgot, if you are interested, look up penrose tiling)


If you look at the above graphic, you will see that it forms hexagons, but out of shapes that are non-hexagonal and have no repeating patterns but cover the plane without gaps or overlaps.
It is a branch of mathematics that is similar to the process used in the holagraphic principle.
I have mapped out to 200ly from earth using it. That was when my kids were young and I had no time for FTF gaming. I may update it to do the sol sector but, I am getting too old for that sort of work. That is a young man's game.

Strangely enough, I find far more people who enjoy this sort of thing happen to be Traveller players.

I was actually hoping it might get into your WBH as an appendix or something. I have had far too many arguments about Traveller maps and space being 3d, so it would be nice to have the article there for no other reason but to tell them to read the article while the rest of us get back to playing the game. (no need for attribution) Sadly, I know this will still not fully work as many people use the argument about flat world maps proving that the earth is flat.....

 

[Geir]

I was actually hoping it might get into your WBH as an appendix or something. I have had far too many arguments about Traveller maps and space being 3d, so it would be nice to have the article there for no other reason but to tell them to read the article while the rest of us get back to playing the game. (no need for attribution) Sadly, I know this will still not fully work as many people use the argument about flat world maps proving that the earth is flat.....

That book is literally up against the page count, so no room for more appendixes or detail.
This sort of thing, especially for areas around Sol, could be very useful for settings that are focused on the area. Both the Cepheus-based Hostile and Clement Sector (well, actually the Earth Sector) settings could probably have benefited from a more complete mapping of local space.

 

[Dalton Calford]

Hmmm, page count.....I know, make the pages bigger!!

 

[Sigtrygg]

Dalton's 3d interpolation deserves to be canonised - I think I called for it in another thread too

I would like to see the full version without the 10 pages getting cut. It should definitely be in any supplement to WBH or the revised Traveller Companion.

 

[Dalton Calford]

Dalton's 3d interpolation deserves to be canonised - I think I called for it in another thread too

I would like to see the full version without the 10 pages getting cut. It should definitely be in any supplement to WBH or the revised Traveller Companion.

you want to see the math of a madman??? you are braver than I. Trying to write that up was enough of an explanation as to why in the chuthulu mythos math=magic=madness.
I am sure I lost a few sanity points trying to explain topology.
It's almost as insane as figuring out if something is fraudulent or not by counting the statistical curve of the first digit occurring within a data set.
(yes this is a thing, used to see if a photo has been modified or if someone is cooking the books)
Honestly, it would not help you much, and it was justifiably cut.
But, if you want to learn what I am discussing, there are teachers who are much better than I in describing what I am doing.

 

[Sigtrygg]

The maths is what interests me...

and like I've said I think your concept is a brilliant explanation.

 

[Dalton Calford]

The maths is what interests me...

and like I've said I think your concept is a brilliant explanation.

Well the math is quite complex and like most math, very generalized.
I think you are more interested in the implementation process.

So, that I can explain. I happened to use a program called nbos astrosynthsis 3, but a spreadsheet can be used as well.

Step 1. Gather together the x,y position of stars in light years. No other data is needed. They can be relative to the galactic center or earth or any arbitrary xyz frame of reference.

Step 2. Calculate the distance between each and every star.
If the distance is 1.8 ly or less, tag those star together into a system. (This is a sphere that covers the current cubic pc and overlaps the neighbors by a little bit)
Now that you have worked out the "systems", calculate the center of the system ie the average midpoint for each of them.

This is your new xyz grid.
Step 3. Pick a central system. That system is a cubic parsec. Since you know it's xyz center point, you can work out if any systems are in one of the neighbouring 26 cubes around that central system. The distance is between 3.26 and 10ly based upon angle. (Refer to diagrams for how this works)
Place them as per the diagram in the article.
Starting with the inner ring, then the middle ring.
For the first system, use the placement in the diagram as shown, but as you add systems beyond the first, you will find that the placement on the outer ring will need to be adjusted.

Step 4. Pick a new system that is not already mapped, but which shares some of the systems mapped to your first system. Map up this new system, overlapping any shared relationships with the first system. Remember that outer ring system placement can rotate but keep in mind real world xyz distance when placing the outer ring systems.

Step 5. Pick a new system and repeat the work of step 4 until no more systems remain unmapped.

You have effectively separated space into 20ly cubes, that overlap by about 3.5ly to a side.

(Central system, 10ly radius, trimmed as a slight ly deformed cube)

My first pass at this was using nbos astro 2 and a diagramming program called yED.

Second pass was a series of macros that would process the systems and change a text value on the system that held its position within hexagonal xy space.

As each new system was added, it would nudge these values depending upon overall placement.

Finally I showed my work to one of my wife's friends who is a math teacher and she immediately saw what I was up to and put me in touch with a professor who showed me what I was doing wrong. That led to my further breaking down a single system into 27 cubes, a 3x3x3 grid, each slightly larger than a ly to a side (3.26/3). This held the original xyz position within the system so that it could be extrapolated back out to 3d.

So the whole thing is a series of cubes within cubes, spread out onto a plane. The computer version that I ended up with was based on Einstein's work (he did alot more than just physics, he was a mathematician first and foremost). That was a period of months of difficult work studying to understand how it works. I hope that I may reach the point of understanding that I can explain it simply (a task I am not yet up to). But at least I can do it manually or program it up in Pascal.
Hopefully this rambling made some sense to you.
Best regards,

 

[Sigtrygg]

Yes it makes sense, and thank you for all the time and effort you have put into this.

Would still like to see the maths though

 

[Bill Sheil]

Might just be bad luck on my part, but I've never had Traveller worlds generate a system that I'd actually want to use. Which is probably just the nature of random, it doesn't have any means of selecting for interesting.

Habitable zone worlds where Nitrogen freezes are not 'interesting' ?

But seriously 'credible' is a bigger problem for Traveller Worlds IMO. We have started trying to use Traveller Worlds as a baseline in our Traveller Adventure campaign partly on the basis that, while not official, it exists 'under the wing' of TravellerMap and therefore feels semi-canonical, so long as the seeds remain constant. But yeah! They are interesting enough when our intention is to describe a lot more detail about the systems than is usually covered in the "you jump into this system and land on the planet. It's cold and dry" level of Traveller description.

But I was already having concerns about some of the values a few weeks ago as we started to look at describing stuff in detail and then along came the WBH which exposed the obvious error in Traveller Worlds.

Sometime, maybe this weekend, I will make a post describing the differences and any amelioration steps that need to be made to fix and bring Traveller Worlds generated systems into the improved WBH standard. Apart from an Albedo convertor my feeling at the moment is that the greenhouse factor in Traveller Worlds already has the fourth root baked into it so should be applied directly. And an orbit fraction adjustment may be needed as many of the worlds are still too damned cold.

Still waiting for a response for COTI access, though.