[Spaceships] Dealing with Cheap World-Killers?

[DataPacRat]

I'm putting together a setting that's roughly TL10, no FTL or other superscience save for two items, which are close enough to what Spaceships calls a Singularity Drive and a Vacuum Energy plant that I'll just swipe the stats.

Of course, with no delta-v limits, it's possible to throw together something like the World-Killer from SS3, for under $1B. (SM+12, mostly Stone Armor, $550M for the automated drive, $75M for an automated SM+11 control room, $50M for stealth, $35M for chameleon, maybe $15M+$3M for a few SM+9 UV lasers and fission plants to discourage would-be heroes.) Sure, it's only got an accel of 0.5G, but once it's built, you can send it racing off away from a solar system to stop at a distance of 0.75 lightyears, then turn it around and have it arrive at 0.9c. An online relativistic calculator I found implies the impact would be 2,521 teratons, 25 times that of the dinosaur-killer. (Or, in Spaceships terms, collision damage of 9d*100,000,000.)

The trouble is, I'm actually aiming for a generally /hopeful/ setting - something closer to the Iain Banks' Culture than Eclipse Phase. And now I'm having trouble coming up with a way to reconcile "life is generally at least as cool as having a volcano lair populated by catgirls" with "any billionaire (or billion-dollar-scale company or group) who has a mind to, can exterminate life on a planet", without dropping too far into mind-control ickiness that negates the main theme. I mean, sure, once you raise everyone to a better-than-today's-first-world standard of living, cure aging and disease, offer optional uploading-based immortality to anyone who wants it, and have a galaxy full of living space to spread out into to avoid over-crowding, /most/ reasons anyone sane would have to threaten a planet with doomsday just go away.

Anyone have any ideas for how the remainder of potential world-killers might generally be dealt with? Eg, ultra-tech versions of today's "nudge units" with the target of nudging people towards at least a minimal level of sanity and cooperativeness? Wide-spread surveillance to keep track of everyone's behaviour, with increasing focus on people who are more likely to want to cause gigadeaths, leading towards more heavy-handed interventions? Flashmob-style disorganized organization to crowdsource lovebombing and other psychological boosters? Generally giving up on any large planets or stations, focusing instead on smaller habitats that can /duck/?

What options would cause the least strain to your willing suspension of disbelief?

(Other than having relatively secret offline backup sites hidden in various locations to reboot interstellar civilization from, if need be. I've already got that aspect well-covered. :) )

[Fred Brackin]

Originally Posted by DataPacRat

What options would cause the least strain to your willing suspension of disbelief?

A Space Navy or at least an Oribal Coast Guard to blow up any World-killers before they hit. It'd be much easier than Universal and Infallible Craziness Prevention.

The Orbital Guard would have many uses that were less apocalyptic.

[Anthony]

Any vacuum energy plant is still pulling energy from somewhere, just in this case it's the structure of space. That energy source can easily have a velocity, in which case performance would naturally drop off at high relative velocities (most likely it behaves like drag, in which case ships using that drive type have a speed limit). You still can't avoid having quite dangerous stuff around, but it eliminates the relativistic impactor.

This won't help if you actually need things moving at the higher speeds.

[ericthered]

Don't put civilization on planets. If you have super plentiful energy not dependent on stars, you have no real reason to stay on a planet. Put everyone in rotating habitats and it becomes much harder to kill massive amounts of people. You can still do it, but it becomes senseless loss of life rather than a civilization crippling blow, which is what we'd really worry about.

[DataPacRat]

Originally Posted by Fred Brackin

A Space Navy or at least an Oribal Coast Guard to blow up any World-killers before they hit. It'd be much easier than Universal and Infallible Craziness Prevention.

The Orbital Guard would have many uses that were less apocalyptic.

Hm... I'm assuming the existence of Robofacs which can Von Neumann themselves to higher output levels; and that people are spreading to a variety of stars. If folk around one star went suddenly crazy, built themselves a world-killer, and launched it towards a planet 5 light-years away, how soon would the rock be detected?

Let's see, SSp44, 12 (SM+12), -2 (Pyramid 34 armor), +5 (half-hour sweeps), -75 (7B miles), +32 (SM+31 array), +10 (in plain sight), +24 (silhouetted against deep space), -8 (stealth hull) = total -2 to detect from across the system. Even assuming a $900 quadrillion automated sensor array, it's not until the rock is 300 light-seconds away that it's autodetected, which doesn't give a lot of time to get any kind of interception into place.

Even with all the rear systems being Hot Singularity Drives, pushing at 6 gees, in 300 seconds, an interceptor could only move itself about 1600 miles, meaning they'd have to be peppered pretty thickly around any potential-target planet. And even then, a pile of rubble hitting a planet at .9c is almost as bad as a single solid rock doing the same.

How else might a Guard try to handle the situation?

Originally Posted by Anthony

Any vacuum energy plant is still pulling energy from somewhere, just in this case it's the structure of space. That energy source can easily have a velocity, in which case performance would naturally drop off at high relative velocities (most likely it behaves like drag, in which case ships using that drive type have a speed limit). You still can't avoid having quite dangerous stuff around, but it eliminates the relativistic impactor.

This won't help if you actually need things moving at the higher speeds.

I'm not /exactly/ using vacuum energy, that's just the closest equivalent in existing GURPS books. (I'm positing something called "horizon mechanics", an expansion of the present-day theory called "quantized inertia".) I'm prepping some lovely over-pretentious technobabble that has a core of actual math. (If it matters, what's being drawn on to create the energy or momentum is cutting off all future access to a sliver of the universe near the Hubble horizon; or, put another way, converting information into energy. Which, in this theory, is also how the forces of inertia and gravity are generated.)

Originally Posted by ericthered

Don't put civilization on planets. If you have super plentiful energy not dependent on stars, you have no real reason to stay on a planet. Put everyone in rotating habitats and it becomes much harder to kill massive amounts of people. You can still do it, but it becomes senseless loss of life rather than a civilization crippling blow, which is what we'd really worry about.

That's rapidly becoming my fallback plan, if I don't think of any way to keep planets intact.

[malloyd]

Originally Posted by Anthony

Any vacuum energy plant is still pulling energy from somewhere, just in this case it's the structure of space. That energy source can easily have a velocity, in which case performance would naturally drop off at high relative velocities (most likely it behaves like drag, in which case ships using that drive type have a speed limit). You still can't avoid having quite dangerous stuff around, but it eliminates the relativistic impactor.

This won't help if you actually need things moving at the higher speeds.

And may just drive the problem somewhere else anyway.

The issue here isn't really the spacecraft, it's the power plant. If power plants that can generate enough energy to kill a planet, preventing them from applying that energy to an impactor just means you need some other energy release mechanism if you want to do that. Imposing a velocity limit doesn't prevent somebody from using the power plant to boil the ocean.

This is usually hidden in SF settings because the non-propulsive applications of power plants capable of pushing ships that fast are routinely ignored. But it's just a genre convention. Fast space travel that doesn't cheat physics too blatantly necessarily involves energy levels of the sort no sane government lets your typical party of PCs get anywhere close to. Given that you are going to need a departure from reality anyway you might as well put it in as a flat "planet killers just don't work" rather than trying to impose some weird limit on velocities that may not actually prevent them anyway.

[Anthony]

Originally Posted by malloyd

And may just drive the problem somewhere else anyway.

The issue here isn't really the spacecraft, it's the power plant.

Well, no. I'm assuming a singularity drive as per Spaceships p33, which is a reactionless drive and thus, absent some creative speed limit, violates conservation of energy.

[DataPacRat]

Originally Posted by malloyd

Given that you are going to need a departure from reality anyway you might as well put it in as a flat "planet killers just don't work" rather than trying to impose some weird limit on velocities that may not actually prevent them anyway.

I have a strong preference for "rational" fiction which carefully avoids sweeping such issues under the metaphorical rug.

Originally Posted by Anthony

Well, no. I'm assuming a singularity drive as per Spaceships p33, which is a reactionless drive and thus, absent some creative speed limit, violates conservation of energy.

"Horizon Mechanics" expands conservation of mass-energy to conservation of information-mass-energy. Using a drive or plant based on its principles simply means that a few tens of billions light-years away, there are slightly fewer places that will ever be within your future light-cone. But since you routinely snip away similar amounts of spacetime every second just by swinging around the sun, and by your body's electrons swinging around your body's atomic nuclei, you're not really losing anything you'd ever notice, even if you figured out how to start spreading your descendants at 0.999999 of lightspeed.

All of which adds up to, in effect, violation of conservation of energy. :)

(Feel free to suggest any poetical metaphors that come to mind, such as "burning spacetime in the photonic engines". :) )

[malloyd]

Originally Posted by DataPacRat

"Horizon Mechanics" expands conservation of mass-energy to conservation of information-mass-energy. Using a drive or plant based on its principles simply means that a few tens of billions light-years away, there are slightly fewer places that will ever be within your future light-cone.

Whose light cones? Atoms that have been too close to the power plant?

I suppose creating energy means the local gravitational curvature goes up (there's more mass here than their was before) which you could probably handwave into some sort of consistent effect beyond slowing the expansion of the universe locally.

[Anthony]

Originally Posted by DataPacRat

"Horizon Mechanics" expands conservation of mass-energy to conservation of information-mass-energy.

That's not actually an expansion, current theory is that information should never disappear (hence the black hole information paradox).

In any case, vacuum energy plants already violate conservation of energy, so that's not the issue per se; the issue is the rate. A 1G SM+11 ship with a reactionless drive is violating conservation of energy at up to 9e+16W. By comparison, 1 EP appears to be about 100W/kg or 3e+9W on that ship, so your engine is producing the equivalent of 30,000,000 power points.

In practice, any actually interesting ship drive is a WMD, but limiting your drive to, say, 100 km/s, and assuming you can push on the structure of space rather than producing a photon drive, reduces the free energy to about 3e+12W, which is a lot less troublesome.