• Welcome to the new COTI server. We've moved the Citizens to a new server. Please let us know in the COTI Website issue forum if you find any problems.
  • We, the systems administration staff, apologize for this unexpected outage of the boards. We have resolved the root cause of the problem and there should be no further disruptions.

Voyager Alpha - Worldbuilding IMTU

Thanks for your input! I guess I will go with a custom extension.

BTW, atmosphere creation is nearly done and online. Nice to see how Hydrosphere and Biosphere are natural spin-offs of the Atmosphere.

TODOs:
- CO2 washout
- NO2/N2O4 temperature-dependent phase transition
- Native Life and effect on O2 in atmosphere

The most difficult part in life creation seems to be the availability of liquid water...
 
thalassogen said:
Please, let me know when you find any errors, weirdness, or believability-issues!
Click to expand...

I noticed this on planet T VI:

Mass: 0.1194 terra (7.13e+023 kg)
Density: 1.16 terra (6.38 g/cm³)


The size, mass, and mean density of a solid planet are in logarithmic proportional to one another due to gravitational self-compression.
Where units m, r, and d are mass, radius and density (Earth= 1), then:

ln(2d) = ln(2) × r and 2d = 2^r

So

m = exp(r × ln(2)) / 2 × r³ = r³ 2^(r-1)
r = ln(2d)/ln(2)

This is the case for a silicate-nickel-iron exoplanet with the same composition, mass distribution, and core-mass fraction as Earth (32.5%). The radius for icy or watery bodies will be 1/3 to 2/3 larger than indicated.

**Mass from Radius**
Moon: m = (exp(0.272798619 × ln(2)) / 2 × 0.272798619³ = 0.012263574
Mars: m = (exp(0.533040339 × ln(2)) / 2 × 0.0.533040339³ = 0.109574971
Venus: m = (exp(0.949929367 × ln(2)) / 2 × 0.949929367³ = 0.827944414
Earth: m = (exp(1 × ln(2)) / 2 × 1³ = 1

The Venus mass is actually 0.815; a bit of variance with the computed 0.8279, most likely because of reduced core size.
 
Thanks for these details, I wasn't aware of the importance of gravitational compression! And important it is: Density of Earth: ~5.5 vs. uncompressed: ~4.4

At first I thought this to be an "oddity" like Mercury (i.e. a very large NiFe core) but upon looking into this I saw it coming up rather often. I will change the algorithm to reflect the more common relation and keep an density-exaggeration backdoor for the occasional weirdo planet.
 
I just uploaded a major update:
- fixed general density calculations based on shaunhilburn's explanations, but still allowing for the odd Mercury here and there
- allowed life to evolve and prosper (classification of life listed below)
- added iterative albedo calculation based on changing world conditions (e.g. caused by life)

Classes of life
* Simple: mono-cellular organisms, simple multi-cellular organisms, bacteria, algae, etc.
* Complex: complex multi-cellular organisms, plants, lower animals
* Sapient Sentient: higher animals (or plants if you will)
* Sentient Sapient: language- and tool-using beings
 
Last edited:
Sentient vs. Sapient

thalassogen said:
Classes of life

* Sapient: higher animals (or plants if you will)
* Sentient: language- and tool-using beings
Click to expand...

Not to be nit-picky, but perhaps these two category titles should be reversed based on the meaning of the words:

"Sentient" means "sensing" or "aware", whereas "Sapient' means "wise" (it is the Latin equivalent/cognate of Greek "Sophont", and is used in Homo sapiens - "Wise Man").
 
Last edited:
You are TOTALLY right! I got this one wrong during my evolution procedure. :-(
Now it is corrected and online.
Thanks for pointing me towards this!
 
Current working items are:
- eccentricity
- inclination
- moons
- improvement of atmosphere simulation


Meanwhile, I am pondering the sector mapping topic: 2D or 3D?

2D is much simpler and easy to understand for new players. 3D is more realistic and (yes, I am geeky at that) SO COOL when animated, but we'll likely need a computer/tablet at the gaming table (something I avoided for the last 20+ years).

What are your thoughts?
 
thalassogen said:
Meanwhile, I am pondering the sector mapping topic: 2D or 3D?

2D is much simpler and easy to understand for new players. 3D is more realistic and (yes, I am geeky at that) SO COOL when animated, but we'll likely need a computer/tablet at the gaming table (something I avoided for the last 20+ years).

What are your thoughts?
Click to expand...


I am always in favor of 3D if it is at all feasible (yes, it is more work, but it definitely adds a more realistic/believable feel).
 
I like 3 D as well, and have used Astrosynth and Celestia (although it was some time ago,) and can recommend both of them.
 
OK, I guess, I will go with 3D indeed.

I just downloaded and installed Celestia and Astrosynthesis Trial. These programs are nice but not quite to my liking. I guess I will have to code a 3D viewer for my website output myself.
Or maybe you have some pointers for me explaining how to use these programs with Traveller?
 
thalassogen said:
Current working items are:
- eccentricity
- inclination
- moons
- improvement of atmosphere simulation
Click to expand...

Current state (not online yet):
- eccentricity done
- inclination done (needs additional parameters to be of any meaning, though)
- slight improvements to atmosphere simulation
- moons: HEADACHE

I had hoped for an Accrete-like algorithm to produce suitable satellite systems, but am getting only planetoids far too many for dwarf planets and far too few for gas giants.

Do you have any suggestions?
 
Still no satisfying moons yet. May need to fudge that.

As a side note: I originally intended to implement a scout/explorer campaign IMTU. That idea still stands but discussion in another forum spawned some additional thoughts...
- sapient species will survive only a few million years
- there may be one such species per ten thousand stars
- so the milky way will have a potential of about 10 million sapient species
- the oldest may have developed about 3 billion years ago and more are to come in the future
- so there may develop one sapient species per thousand years
- the chance of staying long enough alive to develop sophisticated technology may be good and maybe they do not destroy themselves and last another thousand years, but ultimately the chance to meet another sapient is very slim, and even discovering foreign intelligent signals requires a species to stay long enough alive to match the timespan another species is able to broadcast
- so maybe about 1 species in ten thousand years reaches that kind of technology
- and maybe about 1 species in hundred thousand years stays alive long enough to extensively study surrounding space, another such species must be within a few thousand light years to be recognized and may be extinct at the time their broadcast is received

Just some thoughts. But I like the idea that humanity is the first species that lives long enough to colonize surrounding space, or at least is currently the most advanced one in its region of space.
 
You must log in or register to reply here.

Similar threads

Tobias
Ship tonnage
2 3 4
Replies
60
Views
2K
McPerth
McPerth
K
Urakkalan and Vland
2
Replies
33
Views
3K
tjoneslo
T
Badenov
Cargo Capacity and volume and mass
10 11 12
Replies
234
Views
8K
aramis
aramis
F
Looking for players for a gritty Mercenary campaign [Traveller MGT2E] [Paid] [Online] [Tuesday 1.30 PM GMT/8:30 AM EST] [LF2M] [Foundry VTT]
Replies
0
Views
568
Frenesires
F
S
Tug Concept
2
Replies
34
Views
907
aramis
aramis
Back
Top