Map of the Steppes (Seren-Tinza) Front

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Arioch »

Mayhem wrote: Presumably the Soia Empire extended way beyond the Local Bubble. How big are we talking? 5,000-10,000 light-years? Did they manage to leave the Orion Spur?
There is only very limited contact with regions outside the local bubble, but from what little there has been, it seems clear that they have Soia ruins too. Beyond that, there is no way for the Local races to know.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Drek »

Gah. This is gonna bug me until I ask about it. If I remember right (and my knowledge of Soia history is shaky at best), the Soia empire fell about 500,000 years ago. As we ponder that figure in relation to evolution and whatnot in this and other threads, I feel compelled to note that galactic geography is not fixed. That is to say, stars MOVE relative to each other as they orbit the galactic center. Our sun, for example, is about (http://en.wikipedia.org/wiki/Orion_Arm) half way across the Orion arm and is cooking along at about a (http://en.wikipedia.org/wiki/Sun#Motion ... the_galaxy)light year every 1,190 years. That means that since the Soia empire fell, the solar system has moved about 420 light years, or close to half the width of the local bubble itself. Everything else is moving too, granted, but not in precisely the same direction or at the same speed and when a safe jump is ~6 light years, 420 light years is a LOT of motion.

So, in short, if we're going to try to map current astro-political conditions and biological distributions onto the history of the Soia, it would help a lot to know how similar the current positions of stars are to the positions THEN.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by GeoModder »

500,000 years? every single star must have drifted at least a hundred lightyear away from its then neighbours.
And from most stars in today's astro databases the velocity -and direction they're heading isn't know accurately enough to backtrack them half an eon.

Actually, there's a good example of stellar drift in accordance with interstellar colonisation in the comic: the morat and their Delrias cousins in Loroi space. IIRC the Delrias are located pretty close to the three sisterworlds, while the Morat are at the edge of Loroi space within the Umiak sphere. If we assume that both planets lost contact by the time of the fall of the Soia Empire, they drifted apart quite a distance sce then.
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Re: Map of the Steppes (Seren-Tinza) Front

Post by Mjolnir »

GeoModder wrote:500,000 years? every single star must have drifted at least a hundred lightyear away from its then neighbours.
And from most stars in today's astro databases the velocity -and direction they're heading isn't know accurately enough to backtrack them half an eon.
Note that this is largely due to us not having FTL travel. We're measuring transverse velocity perpendicular to the direction we see the star in directly in angular units (which requires extreme measurement precision), and radial velocity measurements are made by doppler (limited by the need for clear spectral lines, which the motion of emitting plasma particles and the rotation of the star itself interferes with) and by changes in parallax over time, which is limited by the radius of Earth's orbit (very small angular measurements again). Translation from angular transverse velocity to linear transverse velocity requires good information on distance, and overall relative velocity needs both.

An interstellar civilization that's been operating for any amount of time will have a range of extremely-long-baseline parallax measurements and spectral radial velocity measurements from a variety of angles to work with, and would have vastly more accurate measurements of position and velocity than we do.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by GeoModder »

Mjolnir wrote: An interstellar civilization that's been operating for any amount of time will have a range of extremely-long-baseline parallax measurements and spectral radial velocity measurements from a variety of angles to work with, and would have vastly more accurate measurements of position and velocity than we do.
It's only too bad some consortium of space agencies don't envision a mission to put some astrometric probes in the orbit of one of the jovian planets. alot more precise information could be gathered from stars way further out. Say the L4-5 points of Saturn orbit would be nice. And those are supposed to be alot 'emptier' then those of Jupiter.
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Re: Map of the Steppes (Seren-Tinza) Front

Post by Arioch »

Most of the stars in the galactic arm are moving together at more or less the same speed, orbiting the galactic center at about 220 km/s. A complete orbit takes 200 million years. So yes, that's a movement of almost 400 light years in half a million years, but the Sun is moving along with the rest of the stars.

The stars do move relative to each other, but not nearly as much; the Sun's movement relative to the average motion of the stars around us (Local Standard of Rest) is only about 10 km/s. That's a displacement of 16.7 light years in half a million years. A few stars have much higher relative motions, but they tend to be older Population II stars that have very eccentric orbits around the galactic center. 82 Eridani, for example, has a very high relative space velocity (to the Sun) of about 100 km/s.

The shape of the bubbles of interstellar gas (blown out by supernovae) can change noticeably over this scale of time, but the star formations that they trigger take many millions of years.

So yes, local starmaps will change significantly over the course of half a million years, but the large-scale structure of the galactic arm will have changed very little in such a small amount of time.
GeoModder wrote:Actually, there's a good example of stellar drift in accordance with interstellar colonisation in the comic: the morat and their Delrias cousins in Loroi space. IIRC the Delrias are located pretty close to the three sisterworlds, while the Morat are at the edge of Loroi space within the Umiak sphere. If we assume that both planets lost contact by the time of the fall of the Soia Empire, they drifted apart quite a distance sce then.
The separation of the Delrias and Morat from each other is meant to indicate that their ancient empire was very large, not that the stars drifted from each other.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Drek »

The stars do move relative to each other, but not nearly as much; the Sun's movement relative to the average motion of the stars around us (Local Standard of Rest) is only about 10 km/s. That's a displacement of 16.7 light years in half a million years.
You're right of course, but what matters isn't real space distance per se but rather jump links. If we think about jumpable distances we can view the whole thing as a graph with stars as the vertices and jump paths as the edges. My guess, given that I've never really thought about it given our pronounced lack of jump drives, is that we'd get a sparse, random graph (certainly not small world or scale free) with a low to moderate clustering coefficient to account for gravitationally bound objects. That type of graph is not robust against the loss of edges (i.e. the drift of two stars beyond jump range) and so the geodesic path between two stars could change rather dramatically with just a small number of changes in stellar position. As a result, 500,000 years might not be enough to completely shuffle the vertices that were within a given volume, but it could pretty substantially alter the edges between them.

Of course, all of this depends rather heavily on how jumps would work in certain cases (e.g. binaries where the components are separated by ~1/2 a light year) as there might be some stellar configurations that are more robust against this type of disruption.

Not trying to be ornery, I actually love the comic, I just find this line of thought interesting.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Arioch »

If you mean that the web of jump links changes substantially over very long periods of time, I certainly agree. But I don't know that the placement of individual jump links has very significant implications for the consideration of an ancient empire's large-scale reach (if that was your larger point).

If I traveled to Greece to Thermopylae and looked for the pass where the 480 BC battle took place, I won't find it, because the shoreline has changed a great deal in the intervening 2500 years. However, the large-scale map of Greece has changed very little in that time, comparatively speaking.

It is interesting, though, to think that all three of the stars that I had populated with extrasolar colonies (Alpha Centauri, Tau Ceti, and 82 Eridani) have very high relative space velocities, and will be taken very far away from Sol over the coming millennia. But, if your interstellar civilization lasts for tens of thousands of years, I guess that's a problem you wouldn't mind having.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by GeoModder »

Arioch wrote:The separation of the Delrias and Morat from each other is meant to indicate that their ancient empire was very large, not that the stars drifted from each other.
Lots of their colonies must have been "de-Moratized" then.
Arioch wrote:It is interesting, though, to think that all three of the stars that I had populated with extrasolar colonies (Alpha Centauri, Tau Ceti, and 82 Eridani) have very high relative space velocities, and will be taken very far away from Sol over the coming millennia. But, if your interstellar civilization lasts for tens of thousands of years, I guess that's a problem you wouldn't mind having.
In the case of Alpha Centauri, it seems 't will keep around for at least the next 50,000 years. ;)

From Wiki:

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A more precise calculation involves taking into account the slight changes in the stellar distance by the star's own motion. Alpha Centauri at present is slowly increasing the measured proper motion and trigonometric parallax as the stars approach us. Changes are also observed in the size of the semi-major axis 'a' of the orbital ellipse increase by 0.03 arcsec per century as the stars currently approach us. Also the orbital period of Alpha Centauri AB is slightly shorter by some 0.006 years per century, caused by the reduced time required for the light to travel to Earth as the distance reduces. Consequently, the observed position angles of the stars are subject to changes in the orbital elements over time, as first determined by W. H. van den Bos in 1926. Some slight differences of about 0.5% in the measured proper motions are caused by Alpha Centauri AB's orbital motion.

Based on these observed proper motions and radial velocities, Alpha Centauri will continue to slowly brighten, passing just north of the Southern Cross or Crux, before moving northwest and up towards the celestial equator and away from the galactic plane. By about 29,700 AD, in the present-day constellation of Hydra, Alpha Centauri will be 1.00 pc or 3.26 ly away. Then it will reach the stationary radial velocity (RVel) of 0.0 km/s and the maximum apparent magnitude of −0.86V — similar to present day Canopus. Soon after this close approach, the system will begin to move away from us, showing a positive radial velocity.

Due to visual perspective, about 100,000 years from now, these stars will reach a final vanishing point and slowly disappear among the countless stars of the Milky Way. Here this once bright yellow star will fall below naked-eye visibility somewhere in the faint present day southern constellation of Telescopium. This unusual location results from Alpha Centauri's orbit around the galactic centre being highly tilted with respect to the plane of our Milky Way galaxy.
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Re: Map of the Steppes (Seren-Tinza) Front

Post by Mjolnir »

Ktrain wrote:Well from what we know about the Soia is that they strictly limited interspecies/cultural interaction. Perhaps they never really engineered any species, but transplanted them from one location to another in order to maintain stability within their empire. What if the Human/Loroi similarities are nothing more than a coincidence that has occurred within an infinitely vast and random universe.
They're right next door, though. They're not from another part of an infinite universe, they're from another part of a very finite empire composed of a chunk of a single galaxy held together by jump links that force ships to take weeks to traverse a system and can't cross an unusually large gap between stars, assuming the Soia didn't have some more capable form of FTL travel. The odds of a duplicate appearing in such a small region of space are pretty much nil.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Shrike »

ColdRain wrote:In rough measure, then, the route from Azimol to Seren looks like about 5 links of around 10 light-years length each. Few of these links will follow the plane of the map, so add, say 50% more to the distance to cover that, for a total of 75 light-years.

Insider's FTL Tech page notes jumps are preferably 6 light-years or less. Stars won't always be positioned for convenience either, so many jumps will be shorter. I'll use 4.5 light-years as a guesstimate of the average distance of a jump along this route.
Hey all. I'm new here and if you don't mind I'm gonna chime in here, since I've done a bit of stellar mapping for unrelated writing projects.

For some quick background it was working on a similar situation as Outsider in that ships could only jump so far (8 LY in my case) and did some mapping on that assumption. One thing I found was that star positions and distances were very random and rarely were less than 4 ly between. For example, going by the 4.5 ly assumption and plugging that into Astrosynthesis (a great program if you haven't seen it, it lets you autogenerate proximity routes) and using Hipparcos data for stars within 50 LY of the Sun you end up with very few routes - basically, isolated clusters. At 6 you start to get interconnectedness and at 8 you can go almost anywhere within reason. Going up to the safe(?) limit of 10 gives you even more routes.

Please note that this is statistical over the volume, not necessarily specific stars. But in general almost every star will have 2-4 jumps manageable at 4-6 with several more at 10. For example Sol has 1 at <4.5, one at <6, one at <8 and three at <10.

I would say very roughly you're doubling the number of routes for every 2 LY increase (this is a very off-the-cuff estimate, just looking at the output).
And additionally Hipparcos doesn't cover extremely faint stars so the output isn't going to be 100% accurate and would open up a greater number of routes, both short and long.

Anyhow, the takeway is that expecting a 4.5 LY average is extremely optimistic. A more typical route would probably be mostly 6 LY jumps with a scattering of 8s.

It's also worth noting that taking the occasional 10 can let you potentially skip over a lot of intervening space. As an example, jumping from Sol to Sirius is an 8.6 ly jump direct. To go there via 'safe' <8 ly jumps would take nine jumps! You have to go almost the exact opposite direction and then loop around to get to Sirius. Of course 8.6 isn't much past 8, so it's not really pushing things - plus Sirius is a fairly massive star and would consequently be easier to 'hit'. But it makes a nice example. Another 10 coming from Sol (to Gliese 65, 8.6 ly as well oddly enough) saves 5 shorter jumps.

Using long jumps can potentially pay significant dividends for shipping firms and militaries. One would expect hyperspatial navigation for identified 'shortcuts' to be extremely valuable, with as much precise navdata available as possible. Shortuctting 4-8 smaller jumps is (IIRC) a month or two saved. That's pretty significant.

And to end things off I've done up some images to show the progression of jump route length.

4.5 ly
6 ly
8 ly
10 ly
Color-coding should be fairly self-explanatory.

Link for Astrosynthesis


This ended up being longer than expected. Hah.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Voitan »

With the talk of stars drifting apart/closer, hyperspace and its relation to gravity wells, and ancient entities beyond our dimension, Outsider could have a literal "the stars are right" moment.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by NOMAD »

I sense a possible Banner of the Stars 1 moment, the Abh empires national anthem.

especially this part
Dear Stars,
Please listen to the wishes of your short-lived kin.

if anyone is interested in the full anthem

http://www.abhnation.com/index.php?opti ... Itemid=150
I am a wander, going from place to place without a home I am a NOMAD

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Luge »

Shrike wrote:For example, going by the 4.5 ly assumption and plugging that into Astrosynthesis (a great program if you haven't seen it, it lets you autogenerate proximity routes) and using Hipparcos data for stars within 50 LY of the Sun you end up with very few routes - basically, isolated clusters. At 6 you start to get interconnectedness and at 8 you can go almost anywhere within reason. Going up to the safe(?) limit of 10 gives you even more routes.
Using long jumps can potentially pay significant dividends for shipping firms and militaries. One would expect hyperspatial navigation for identified 'shortcuts' to be extremely valuable, with as much precise navdata available as possible. Shortuctting 4-8 smaller jumps is (IIRC) a month or two saved.
That's a very cool program. Thanks for introducing me to it! I see what you mean about sirius. With a maximum jump distance of 8LY, you needs to go through another 5 or so systems, resulting in a total distance of 36LY. Increasing jump distance to 8.6 lets you get there directly.

Suddenly those starmaps in Freelancer and Wing Commander make a lot more sense :P

Since you mentioned gravity wells, what's to stop a ship from taking the extremely risky action of jumping into the middle of deep space (Arioch's drawing indicates that shorter jumps are better) and then jumping again to get to a star system. Apart from the fact that its extremly cold in deep space, of course.

L.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Majincarne »

The fact that a safe exit from hyperspace appears to require a gravity well of appreciable size.

So save for the very unlikely and almost non existent black hole in our stellar back yard, a "deep Space" exit isnt going to happen.
its my guess that black holes have enough gravity to them that you could safely jump in at a distance out that would be considered deep space. But there are no black holes know of anywhere near where this is going on, so no deep space exits.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Luge »

Majincarne wrote:The fact that a safe exit from hyperspace appears to require a gravity well of appreciable size.

So save for the very unlikely and almost non existent black hole in our stellar back yard, a "deep Space" exit isnt going to happen.
its my guess that black holes have enough gravity to them that you could safely jump in at a distance out that would be considered deep space. But there are no black holes know of anywhere near where this is going on, so no deep space exits.
Hm.. Then I didn't read Arioch's original "Hyperspace" drawing properly. I thought the green "good" jumps were all away from the deep wells.

Arioch: If you were to add another "very short" jump on your graph, which way would it go?

L.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by captainsmirk »

Luge wrote:
Majincarne wrote:The fact that a safe exit from hyperspace appears to require a gravity well of appreciable size.

So save for the very unlikely and almost non existent black hole in our stellar back yard, a "deep Space" exit isnt going to happen.
its my guess that black holes have enough gravity to them that you could safely jump in at a distance out that would be considered deep space. But there are no black holes know of anywhere near where this is going on, so no deep space exits.
Hm.. Then I didn't read Arioch's original "Hyperspace" drawing properly. I thought the green "good" jumps were all away from the deep wells.

Arioch: If you were to add another "very short" jump on your graph, which way would it go?

L.
What are you defining as "deep space", most people I imagine take it to mean well beyond are star's gravity well. The drive systems in use in Outsider only push a ship into hyperspace they don't offer anyway of exiting, thus they require the gravity well of a star to drag the ship back out of hyperspace. A good jump therefore needs to be within a gravity well, however it is generally preferable to arrive on the edge of a star system as there is generally less to crash into (and you are less likely to be pulled into the star itself, a risk the deeper into the well you jump).

I believe there is already a "very short" jump on the diagram, to the left of the "short" jump, it goes 'Doink!' and the sends the ship bouncing off into hyperspace again to end up who knows where...

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Re: Map of the Steppes (Seren-Tinza) Front

Post by Shrike »

Luge wrote:Hm.. Then I didn't read Arioch's original "Hyperspace" drawing properly. I thought the green "good" jumps were all away from the deep wells.
I think there's a misinterpretation going.

Basically imagine star system being a target 20 AU across, which you need to hit to emerge from hyperspace. If you hit the bullseye (the star) you explode in a fire and die, so you don't want to aim too close, but if you miss by going outside you go all Event Horizon (bad!). It's a tiny fraction of the distance between stars.

And that's why close jumps are preferred, because it's easier to hit your target (like shooting a gun).

Of course as I pointed out, short jumps can be either sub-optimal or completely off the table. And why increasingly accurate hypernavigation would be a growth industry because you can shave a lot of transit time off by using longer jumps, particularly over long trips.

All this blather aside, you can probably expect that you'll need to make about one jump for every 4 LY of direct seperation if you're playing it safe and not exceeding 8 ly per jump - but this is statistical and thus is more relevant for long trips, because stars don't line up nicely for linear travel.

IIRC the Steppes are ~250 ly from Earth, so that's on the order of 60 jumps. I dunno how many they can make in a month, but from the impression I get that's a reasonably substantial distance. A fair chunk of a year, anyhow, if not more.

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Re: Map of the Steppes (Seren-Tinza) Front

Post by fredgiblet »

It took the Bell 2 months to get to Na'am, a Loroi courier could probably make the trip in less than a month.

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Post by Shrike »

Guess I misrembered how long they take to cross a star system and how much burn-time Loroi ships have. Oops!

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