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Old 12-13-2018, 05:51 PM   #31
Rupert
 
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Default Re: FTL Assumptions [Space]

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Originally Posted by copeab View Post
That's the thing, it doesn't have any real velocity. You can't "build up" velocity with it.

If you are talking about falling from orbit, no, it won't work. It's going to fall at the same velocity whether it has a stutterwarp drive or fusion rocket with empty tanks.
Falling builds velocity. You gain altitude with the stutterwarp drive, which does not change your velocity. Then you fall. Then you use your drive. Then you fall again... Now, doing this in the band where the stutterwarp is effective will be fairly slow, but you can do it in a different star system from your target, then warp in, line up, turn the drive off, and your now fractional-c spaceship is a weapon of very massive destruction.
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Old 12-14-2018, 01:45 PM   #32
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Default Re: FTL Assumptions [Space]

And that's why I like jump drives. Limit the distance into the well that the drive can be used to jump out or into a system, and you don't have relativistic planet killers. That's just not a genre of sci-fi I wanna play. But if you like it, go ahead.

I really like Jump Drives, with a strong limitation on where they can be used in terms of in a star system. I like requiring "flat space" to use make jumps, as this requires jump capable ships to still have realistic drives and maneuver systems for operations in system. It also shifts economy to the outer system: harvesting resources from a system doesn't require colonization.
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Old 12-14-2018, 02:15 PM   #33
Fred Brackin
 
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Default Re: FTL Assumptions [Space]

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Originally Posted by Verjigorm View Post
I like requiring "flat space" to use make jumps,
What's your idea of "flat space"?

My rule of thumb is to _not_ make drives that require extremely long trips through normal space to set up. If you send people out beyond Neptune to Jump you're giving any dfender a border that's too long to properly monitor much less defend.

For my Gloria Monday and Tuesday Weld games the Jumplines that people used for interstellar travel required trips averaging about 2 days to reach and this covered about 1 AU in the inner system rather than the outer.

Also, nomal space propulsion was pseudovelcoity with no "memory". Turn it on and you're disconnected from the inertial frame of reference of the universe. Whatever vector you had is _gone_ with the energy therof evenly distributed across the whole universe.

Turn the pseudovelocity drive off and you've got the energy (quietly taken back from the rest of the universe) it takes to make a "normal" orbit around the nearest mass large enough to create frame dragging be that a planet, a sun or a galactic core.

Don't worry so much about "relativistic" projectiles. You need to worry about much slower ones. :) Just falling towards an Earth-sized planet gets you 7 miles per second. That will make a projectile explode as if it were made out of 20x its' own mass in TNT. This increases with the square of velocity.

That's 1 lb of impactor equalling 1 ton of TNT at 70 miles per second. Which puts an SM+4 (10 tons) AKV at 70 mps between the bombs that destroyed Hiroshima and Nagasaki.

So, no long trips through normal space and no newtonian drives capable of making them is my Rule of Sanity.
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Old 12-14-2018, 02:42 PM   #34
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Default Re: FTL Assumptions [Space]

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Originally Posted by Rupert View Post
Falling builds velocity. You gain altitude with the stutterwarp drive, which does not change your velocity. Then you fall again... Now, doing this in the band where the stutterwarp is effective will be fairly slow, but you can do it in a different star system from your target, then warp in, line up, turn the drive off, and your now fractional-c spaceship is a weapon of very massive destruction.
On it's own, perhaps. In the 2300AD setting, not really.

I'll note that inside a gravity stronger than 0.1G, the stutterwarp can't break orbit and will eventually crash, so 0.1G is all you have to work with. Assuming you want a velocity of 0.1 c, that brings of the first problem: powerplant fuel.

Stutterwarp requires a workings piwerplant, and the two most common power plants in the setting are MHD turbines and fuel cells, both burning hydrogen. They will return n out of fuel well before you get to a useful velocity, as 10-20 days of carried fuel is common. Most fision and fusion plants are in large military and commercial ships, and someone will notice if one of those go missing: There are under 50,000 spacecraft in the setting, including small craft, divided among three expliration arms into space, so only really exploration craft, which normally aren't nuclear powered, can go missing and not immediately be thought stolen.

2300AD is also not the 11,000 worlds of the Third Imperium. There are only around 50-60 systems that have been visited in 150 years, due to the 7.7 ly range. All have at least a research out post, and a ship playing yo-yo with a planet for 2 years (only 0.1G, remember) will get noticed. As one poster on CotI said, just dump a huge bucket of gravel in it's path as it heads back down to the Wall and the ship will shred itself.

Oh, sure, a military could do this ... and once news got back to Earth, the country would be vaporized by strategic nukes from multiple countries.

As for terrorists, as I said, nuclear powered ships aren't common and they are going to be highly unlikely to hide playing yo-yo.

In short, limiting the available powrrplants to durations of weeks really nips this in the bud.
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Old 12-14-2018, 02:45 PM   #35
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Default Re: FTL Assumptions [Space]

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Originally Posted by Verjigorm View Post
And that's why I like jump drives. Limit the distance into the well that the drive can be used to jump out or into a system, and you don't have relativistic planet killers. That's just not a genre of sci-fi I wanna play. But if you like it, go ahead.
They work fine for 2300AD because common power plants have very limited duration and there aren't that many systems one can go to.
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Old 12-14-2018, 03:56 PM   #36
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Default Re: FTL Assumptions [Space]

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Originally Posted by copeab View Post
2300AD is also not the 11,000 worlds of the Third Imperium. There are only around 50-60 systems that have been visited in 150 years, due to the 7.7 ly range. All have at least a research out post, and a ship playing yo-yo with a planet for 2 years (only 0.1G, remember) will get noticed. As one poster on CotI said, just dump a huge bucket of gravel in it's path as it heads back down to the Wall and the ship will shred itself.
You don't need 0.1c. Sure it's nice and all, but you don't need that much speed.
Quote:
Oh, sure, a military could do this ... and once news got back to Earth, the country would be vaporized by strategic nukes from multiple countries.
Not in the 2300AD setting it wouldn't, as long as the ship wasn't used, or was only only used on a colony world (though thoroughly nuking the offender's colonies in return would be on the cards). However, there are enough fission powered commercial craft that one going missing (hijacked) would only be of concern to the owner and their insurers.
Quote:
As for terrorists, as I said, nuclear powered ships aren't common and they are going to be highly unlikely to hide playing yo-yo.
There are plenty of side-systems that are linked to the main branches, but uninhabited and unused. The hardest part would be hiding the high real velocity whilst you're dumping warp charge, but as most system have gas giants in their outer systems you could probably get away with it, especially if you weren't over-ambitious about how many systems you moved through.
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Old 12-14-2018, 04:06 PM   #37
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Default Re: FTL Assumptions [Space]

Quote:
Originally Posted by Fred Brackin View Post
What's your idea of "flat space"?

My rule of thumb is to _not_ make drives that require extremely long trips through normal space to set up. If you send people out beyond Neptune to Jump you're giving any dfender a border that's too long to properly monitor much less defend.

For my Gloria Monday and Tuesday Weld games the Jumplines that people used for interstellar travel required trips averaging about 2 days to reach and this covered about 1 AU in the inner system rather than the outer.

Also, nomal space propulsion was pseudovelcoity with no "memory". Turn it on and you're disconnected from the inertial frame of reference of the universe. Whatever vector you had is _gone_ with the energy therof evenly distributed across the whole universe.

Turn the pseudovelocity drive off and you've got the energy (quietly taken back from the rest of the universe) it takes to make a "normal" orbit around the nearest mass large enough to create frame dragging be that a planet, a sun or a galactic core.

Don't worry so much about "relativistic" projectiles. You need to worry about much slower ones. :) Just falling towards an Earth-sized planet gets you 7 miles per second. That will make a projectile explode as if it were made out of 20x its' own mass in TNT. This increases with the square of velocity.

That's 1 lb of impactor equalling 1 ton of TNT at 70 miles per second. Which puts an SM+4 (10 tons) AKV at 70 mps between the bombs that destroyed Hiroshima and Nagasaki.

So, no long trips through normal space and no newtonian drives capable of making them is my Rule of Sanity.
See, I'm trying to purposelessly preserve the realism of outer system travel. So to me, the vast distances are well worth it.

Also, I assume most of the systems around the jumpline are sparsely populated, largely what are mining concerns, harvesting the ready resources of multiple systems, and shuttling them back to the more densely populated systems. In those systems, the outer system is the "civilized" and readily accessible part, while the deep well of the inner system is the fringe.
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Old 12-14-2018, 04:35 PM   #38
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Default Re: FTL Assumptions [Space]

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Originally Posted by Verjigorm View Post
See, I'm trying to purposelessly preserve the realism of outer system travel. So to me, the vast distances are well worth it.

Also, I assume most of the systems around the jumpline are sparsely populated, largely what are mining concerns, harvesting the ready resources of multiple systems, and shuttling them back to the more densely populated systems. In those systems, the outer system is the "civilized" and readily accessible part, while the deep well of the inner system is the fringe.
Tiny spots in the outer system could be 'civilised', but most of it will be empty, and lawless. The inner system is a few tens of cubic AU, the outer is tens of thousands (only counting the planetary disc) to millions (taking it as a sphere), ignoring the outer Kuiper region and the Oort cloud.

If FTL is cheap enough to be shipping the sort of bulk ore and ice that you'll find in the outer system, I expect you'll be using it to travel within the outer system of a star as well as between systems.
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Old 12-14-2018, 05:21 PM   #39
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Default Re: FTL Assumptions [Space]

With the possibly quadrillions of rogue and nomad planets in the galaxy, there is a lot of real estate for exploitation out there (just very, very far from anything warm). With certain types of FTL and fusion power, such objects become viable for colonization and exploitation. Even within 50 ly, there may be 200 million such objects, though I believe the vast majority of them are effectively asteroid belts (a dwarf planet surrounded by debris collected by its gravity).
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Old 12-14-2018, 06:01 PM   #40
Fred Brackin
 
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Default Re: FTL Assumptions [Space]

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Originally Posted by Verjigorm View Post
See, I'm trying to purposelessly preserve the realism of outer system travel. So to me, the vast distances are well worth it.
The "realism of outer system travel" is that it takes years. If every trip to another star requires going through the outer system of each star each way nobody will be able to make money doing it.
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