Transhuman Space/Avatar

[Fred Brackin]

Originally Posted by TGLS

I still feel this discussion is getting hung up on technical details when the real questions ought to be revolving around why people/AIs/etc. in Sol really care about Alpha Centauri.

<shrug>The technical details control what the reality of the situation is to the persons involved.

That reality appears to me to be "Even if _fill in the blank_ is there we can't get there.".

[Cyclone]

Originally Posted by TGLS

Oh, sure launch a starswarm there between 2046 and 2056. Problem is that the starswarm does a fast pass of Alpha Centauri before heading off into deep space until it eventually runs out of power and then hits something. A craft that can stop and look around is several steps beyond a starswarm. A craft that can stop, look around, and return (well I suppose AI could return, but if the goal involves anything involving unobtanium...) is even more steps beyond that.

I think you could maybe do something like they do in the films, only on a microscale (the RDA clearly has insane antimatter production capabilities): brake using antimatter engines. If you only need a few grams of antimatter to do it, you could ~probably~ manage it, as long as you could make a mini-antimatter engine that can maintain containment the whole trip.

Originally Posted by TGLS

Even ignoring the difficulties of getting there and stopping, I fail to see what this adds to the setting beyond, "Great powers are sinking lots of treasure and effort into attempting establishing a colony far away." Unless the adventure is at the colony, of course.

Yes? That's basically the point of the idea - you're on Pandora in the first wave of colonization (or establishing diplomatic relations, or studying the planet's biosphere, or whatever goals the various powers actually orient themselves around), when access to Pandora is incredibly attenuated and you basically have no support and no effective supervisors.

[Fred Brackin]

Originally Posted by Cyclone

I

Yes? That's basically the point of the idea - you're on Pandora in the first wave of colonization (or establishing diplomatic relations, or studying the planet's biosphere, or whatever goals the various powers actually orient themselves around), when access to Pandora is incredibly attenuated and you basically have no support and no effective supervisors.

I think you need to go generic SF or totally ignore Transhuman Space's hard science limits and background history. They just aren't going to fit into what you want.

If you don't want to quite go that far you need to do something just maybe possible like have a wormhole between TS and and Pandora appear out of the black. No reason to put Pandora at Alpha C in this case.

Oh, and don't stick the Solar System's wormhole terminus 750 AU out like the one in Blue Planet. That's too far away to be practical too.

[Cyclone]

Originally Posted by Fred Brackin

I think you need to go generic SF or totally ignore Transhuman Space's hard science limits and background history. They just aren't going to fit into what you want.

If you don't want to quite go that far you need to do something just maybe possible like have a wormhole between TS and and Pandora appear out of the black. No reason to put Pandora at Alpha C in this case.

Oh, and don't stick the Solar System's wormhole terminus 750 AU out like the one in Blue Planet. That's too far away to be practical too.

To put it shortly, I do not think that extremely expensive, limited access to the neighboring Solar system in 20+ year long trips is more unrealistic and soft SF than the greening of Mars.

[TGLS]

Originally Posted by Cyclone

I think you could maybe do something like they do in the films, only on a microscale (the RDA clearly has insane antimatter production capabilities): brake using antimatter engines. If you only need a few grams of antimatter to do it, you could ~probably~ manage it, as long as you could make a mini-antimatter engine that can maintain containment the whole trip.

OK, let's do some more math:
We get a payload that weighs, oh, 1 kg. Probably optimistic, THS computers to run SAI are pretty hefty in of themselves, and it will need to navigate around AC most likely. We set the cruising speed to 20%c, which implies a wet mass of about 1.82 kg, or an even mix of hydrogen and anti-hydrogen of 0.411 kg each. Using the estimate of 1 g ~ 1 TJ for the total energy output of the lasers, that gives an energy requirement of about 1.82 PJ for the lasers. The mass energy of 0.411 kg is about 37 PJ, so assuming 100% efficiency, the total energy requirement of the whole operation is about 40 PJ. Going with a flat inefficiency of 10%, that's about as much energy as electricity Norway consumed in 1998. At a cent a kilowatt-hour this would cost over a billion dollars.

Originally Posted by Cyclone

Yes? That's basically the point of the idea - you're on Pandora in the first wave of colonization (or establishing diplomatic relations, or studying the planet's biosphere, or whatever goals the various powers actually orient themselves around), when access to Pandora is incredibly attenuated and you basically have no support and no effective supervisors.

Surely "build a second laser array to decelerate incoming vessels and/or accelerate outgoing vessels" would be a more plausible first goal here. From a purely energy point of view this makes it about 40 times cheaper to ship stuff to Alpha Centauri, in addition to being able to ship stuff back.

[Fred Brackin]

Originally Posted by Cyclone

To put it shortly, I do not think that extremely expensive, limited access to the neighboring Solar system in 20+ year long trips is more unrealistic and soft SF than the greening of Mars.

The greening of Mars is indeed a problem of credulity but massive improvements in space technology that somehow don't affect the balance of power in the Solar System wouldn't help.

I'm not really sure what you want the Transhuman Space background for but as nearly as I can tell it does not fit what you want it for. You're changing so much you might as well go original. If all of your campaign action s going to be on Pandora you no more need detail on where the PCs came from than the movie did.

[Cyclone]

Originally Posted by Fred Brackin

The greening of Mars is indeed a problem of credulity but massive improvements in space technology that somehow don't affect the balance of power in the Solar System wouldn't help.

A) It wouldn't affect the balance of power in the Solar system that much, since, again, people in THS do not try to wipe all life off the planet - indeed, this is one of the core premises of the setting, right back to the Designer's Notes: "My purpose in writing Transhuman Space was to break away from the prevailing medieval paradigms that dominated past science-fiction roleplaying games [such as] [...] that there will be a dark age, global war, or fall of civilization, often with billions of dead, before the new order is rebuilt on its ashes." Being able to accelerate an object to 0.2c with a huge price tag is useful to wipe out all life on the planet, go to a distant star, and basically nothing else.
B) It doesn't matter if it "affects the balance of power," since the players will be in Alpha Centauri so if the TSA now has a theoretical world-ender, that doesn't really matter. Bully for them.

Originally Posted by Fred Brackin

I'm not really sure what you want the Transhuman Space background for but as nearly as I can tell it does not fit what you want it for. You're changing so much you might as well go original. If all of your campaign action s going to be on Pandora you no more need detail on where the PCs came from than the movie did.

To me, the interesting and cool part of Transhuman Space, and why I would want the PCs to be from THS specifically, is the various political factions and their well-developed and realized cultures, ideologies, advantages, and interests.

Not the specific nuances of THS's space exploitation projections. Which I think are substantially inaccurate [1] and don't matter if you're in another solar system with a single highly expensive ship anyway.

[1]: I think more realistic projection in THS's time frame, even assuming the wild successes in AI and gengineering, is for there to be asteroid exploitation and a bit of manned (or "manned") exploration, no actual colonies or long term civilian habitation.

[Fred Brackin]

Originally Posted by Cyclone

A) It wouldn't affect the balance of power in the Solar system that much, since, again, people in THS do not try to wipe all life off the planet -

It's not just weapons uses that concern me. Making money is useful too and helpful in acquiring political power. Those laser acceleration schemes pretty much require owning the solar system.

If you really have to have the PCs getting to Alpha C through "normal" space travel rather than an arbitrarily located Pandora on the other side of a wormhole see if you can find a copy of David Pulver's Centauri Knights done for BESM for Guardians of Order. It's a little old now (though only a little older than Transhuman Space) and it'll be harder SF than anything you get off the internet.

[Cyclone]

Originally Posted by Fred Brackin

It's not just weapons uses that concern me. Making money is useful too and helpful in acquiring political power. Those laser acceleration schemes pretty much require owning the solar system.

I don't think that is true at all. You just need a power source (either being on Earth or Mercury, in canon THS), a big laser array, and enough money/power to get a bunch of power from the power source. I also think that THS has a lot cheaper energy, because of fusion, because of long-term trends for inflation-adjusted energy prices to go down, and also because of Mercury's solar panels.

Maybe I'm misunderstanding your thinking, though. Is it just you thinking they lack the power capacity for this? Because I really don't see how B follows A here.



One interesting thing I did think of as I considered this question: the same infrastructure is probably able to (with much more conservative laser intensities/max accelerations so it doesn't cost a billion dollars each time you fire it) push objects back and forth between Earth and Mercury via laser sail, effectively voiding the need to use rockets in that region once you develop this tech. At least, once you've got laser arrays on both planets - realistically, you probably only build them one place, but hey, a space race means duplicated infrastructure.

[Fred Brackin]

Originally Posted by Cyclone

push objects back and forth between Earth and Mercury via laser sail, effectively voiding the need to use rockets in that region once you develop this tech. At least, once you've got laser arrays on both planets .

You don't need accelerators of any kind for the Mercury to Earth leg. Light pressure (or the solar wind for magsails) is going straight out at a high intensity.

For Earth to Mercury you need lasers but they'll effectively be pushing sideways to change their orbits from earth's nearly circular one to a highly elliptical transfer orbit. Once you've done that the ships would fall sunward in their new orbits and then re-circularize their orbits into Mercury-touching ones (without assistance).

Outward bound is the only time when you simply use laser beams to push sails in the direction you want then to go.