[Star Trek like] number of planets and sapients

[isf]

Does this look plausible enough for a harder space opera setting loosely based on Star Trek?

I'm planning on using real star data to roughly emulate the spread of the various polities in explored space, so I need a firmer timeline.



Due to Preserver activity, if there is a possibly habitable planet 10% of them have or had some form of life [1.8B]. About 1% of those have sapient life [18M]. About .1% have warp drive [18K]. for a given radius from Earth and a maximum height pf 1000 ly. This is assuming a galactic habitability zone of 22K-30K ly.



100 ly r (0 warp, 2 sapient, 170 live)
250 ly r (1 warp, 500 sapient, 50K live)
500 ly r (43 warp, 43K sapient, 4.3M live)
1000 ly r (172 warp, 172K sapient, 170K live)
2500 ly r (1100 warp, 1.1M sapient, 1M live)
5000 ly r (4300 warp, 4.3M sapient, 4M live)

[maximara]

Originally Posted by isf

Does this look plausible enough for a harder space opera setting loosely based on Star Trek?

I'm planning on using real star data to roughly emulate the spread of the various polities in explored space, so I need a firmer timeline.


Due to Preserver activity, if there is a possibly habitable planet 10% of them have or had some form of life [1.8B]. About 1% of those have sapient life [18M]. About .1% have warp drive [18K]. for a given radius from Earth and a maximum height pf 1000 ly. This is assuming a galactic habitability zone of 22K-30K ly.

100 ly r (0 warp, 2 sapient, 170 live)
250 ly r (1 warp, 500 sapient, 50K live)
500 ly r (43 warp, 43K sapient, 4.3M live)
1000 ly r (172 warp, 172K sapient, 170K live)
2500 ly r (1100 warp, 1.1M sapient, 1M live)
5000 ly r (4300 warp, 4.3M sapient, 4M live)

The flaw in this as pointed out in several of Isaac Arthur's videos (IMHO the entire channel should be a must see for anyone interested in "hard" sci-fi) once warp drive enters the picture with the idea of planets being isolated goes south fast.

In classic Star Trek it was decided that the cube of the Warp number was how fast you were going (there are obvious problems with this idea but let's run with it).

So Warp 6 was 216 times the speed of light. So in one year that civilization could send colonist ships to any (or every) habitable planet 216 light years away. Unless every one of those colonies are abandon our high tech for the simple life they have warp drive and I think you can see where this is going.

[AlexanderHowl]

You have ~16,000 stars in ~11,000 systems within 100 ly, which probably translates to ~110,000 asteroid belts, gas giants, and/or terrestrial planets around the stars. Our current numbers are based on what we can detect, which is fairly limited, as the majority of the detections depend on either large objects close to small stars or objects oriented exactly so that we can observe transits across the star reliably. We are likely seeing the unusual systems rather than the normal systems.

If you take the above assumptions, then we can extrapolate further. Let us extrapolate that a minimum of 20% of the systems have worlds with complex life, a minimum of 20% of those worlds have supported technological sapients in their past, a minimum of 20% of those worlds currently support technological sapients, and a minimum of 20% of those worlds have warp. You would end up with ~2200 worlds with complex life, ~440 worlds with previous technological sapients, ~88 worlds with existent technological sapients, and ~18 species with warp. That is more Star Trek numbers and allows a Warp 6 ship a decent probability of finding something or someone of interest.

[Fred Brackin]

Originally Posted by isf

100 ly r (0 warp, 2 sapient, 170 live)
250 ly r (1 warp, 500 sapient, 50K live)
500 ly r (43 warp, 43K sapient, 4.3M live)
1000 ly r (172 warp, 172K sapient, 170K live)
2500 ly r (1100 warp, 1.1M sapient, 1M live)
5000 ly r (4300 warp, 4.3M sapient, 4M live)

Mixing any period SF with modern hard science in this area works out uncomfortably. Any star with a name of its' own has that because it's bright and bright stars tend to be too young to have Earth-like planets. For example, Sirius is only 240 million years old. Vega is twice that but that's till not nearly enough. Antares is only 11 million years old and isn't going to get much older (BOOM!).

The last time we had at it on these boards we ended up with a hard science number of 200 light-years between Earth-like planets. Even the number you got out of Space 1e was 100 ly. You might have gotten terraformable worlds every 50 or 60 ly.

In terms of useful advice (expecially for a flexible science setting that was Trek-like) I would not try and use Real World data. I'd just make stuff up concentrating on how much time I wanted PCs to spend travelling between planets.

[Flyndaran]

That assumes all species including humans breed like rabbits. Modern prosperous nations barely have population growth. I don't see why futuristic societies would be so different just, because they're colonizing new planets.

Of course over thousands or tens of thousands of years, even minuscule growth would be "problematic" for the genre.

But my "realism issue" with Star Trek type universes is how nearly every major player, even those newly discovered, are at almost the exact same tech level.
It's a fun trope perfect for gaming, but some players may consider it a tripping point for sci fi hardness.

[David Johnston2]

Originally Posted by maximara

So Warp 6 was 216 times the speed of light. So in one year that civilization could send colonist ships to any (or every) habitable planet 216 light years away. Unless every one of those colonies are abandon our high tech for the simple life they have warp drive and I think you can see where this is going.

Assuming it really was like Star Trek, then there are a few things to bear in mind:

1. Humans are freakishly aggressive in their expansionism. Almost none of the species with warp drive capability are nearly as fond of homesteading as humans are.

2. Star Trek is an insanely dangerous universe. Far more, than, say, Star Wars. Human colonies routinely fail as they are eaten by crystal entities, abducted by the Borg, killed by strange radiation and attacked by aliens marking territory.

3. Humanity has a limited shelf life. All the indications are that we'll be extinct in no more than a couple of thousand years. No matter where they go they discover that the planets they visit were previously occupied by people who are gone now, Whether humanity will be gone because they were devoured by eldritch horrors, slaughtered by rebel AI or ascended into balls of light the planets they are occupying now and expanding into in the future will soon be unoccupied again. The races that actually last for a long time are the stodgy conservatives who are disinclined to innovate and expand at more than glacial speed.

[David Johansen]

I liked the premise Lost Unicorn's Star Trek game had, that the Galaxy class ships were essentially seeder ships carrying enough people to start over if Earth finally fell.

[Flyndaran]

But also humanity is far far FAR more inventive and luckier than any other species.

[Phantasm]

What I did for my own setting was hunt down the K, G, and F type stars in a given radius from Sol using the Internet Stellar Database. It's a little out of date, but I mostly ignore the M type stars for being too dim or flare-laden to have habitable worlds (though of course humans being humans we'd build sealed environment colonies anywhere , so the red dwarfs aren't entirely useless). The K, G, and F type stars would be the ones most likely to have what Star Trek calls M-type planets (tectonically active habitable planets, basically).

And then I limited my homeworlds to a third to a quarter of those systems. Of those homeworlds, only two so far reached the same level of tech as Earth on their own and one started ahead of Earth technologically before being abandoned millennia ago, leaving behind their sapient robots.

Then again, I operate on a smaller scale than most, having a heavily settled core 20 lightyears in radius from Earth, and a partially settled frontier of 30 to 100 lightyears in radius around Earth. In a Star Trek: Enterprise game, I'd multiply those by ten, in TOS by 100, and in TNG by 1000.

[isf]

Originally Posted by maximara

The flaw in this as pointed out in several of Isaac Arthur's videos (IMHO the entire channel should be a must see for anyone interested in "hard" sci-fi) once warp drive enters the picture with the idea of planets being isolated goes south fast.

I have watched several of his videos and also recommend them. The existence of some tl^ in the setting makes many of his analysis less useful/

Originally Posted by maximara

In classic Star Trek it was decided that the cube of the Warp number was how fast you were going (there are obvious problems with this idea but let's run with it).

That's the scale that I'm planning on using so far to give mostly consistent travel times.

Originally Posted by maximara

So Warp 6 was 216 times the speed of light. So in one year that civilization could send colonist ships to any (or every) habitable planet 216 light years away. Unless every one of those colonies are abandon our high tech for the simple life they have warp drive and I think you can see where this is going.

Yes, but warp 6 isn't going to be a common;y achieved speed until late in the setting. Warp 1 or 2 is likely to be more common.