General Product hulls

[oldmill]

Hi, I'm wondering about how the hulls are made and I don't really get it.

It is described in Fleet of worlds as follows: "The supermolecule's imperviousness derives from interatomic bonds artificially strengthened using an embedded power plant."

What does "embedded power plant" mean? Is it "power plant" as in "nuclear power plant" or is it something else? Where is it embedded?

Can anyone help me with this?

Thanx

[chrispenycate]

I doubt whether Niven himself knew this; after all, if he could build (or if humanity at the time of Beowulf Schaeffer had been able to duplicate) a GP hull, it would have been done. But I don't think the power supply could have been remote, and macroscopic; if you'd needed connections to your main ship systems to keep your hull stable, that would have been much too dangerous for a puppeteer. And the energy conduits would have been vulnerable points in a shell that should have had none at all.

So the power supplies should have been molecular, small enough that they don't compromise the overall transparency, and distributed homogeneously over the entire surface. Energised by a slow decaying radioactive, perhaps, or cold fusion? Maybe a few atoms of magnetically suspended anti-matter? It sort of suggests that a GP hull has a limited life expectancy, probably not more than a few tens of thousands of years, before reverting to a mere passive shell, hardly tougher than diamond.

[ghost8772]

Wasn't the ship in Ringworld a GP hull? what I remember the hull was fairly strong, but not impervious, they had it set up that a stasis field was set up over the continuous hull, wings and external equipment and thrusters,were outside that line. if something threatened the integrity of the hull, the stasis field engaged and would not allow anything inside the outside line of the atoms comprising the hull. its how they landed initially on the ringworld, and if I recall correctly, the ship in ringworld engineers ended up buried in the world itself following the same trend. something happened to the ship, when it crashed the stasis field energised and once everything was "safe" again it turned off. to the occupants it felt like they blinked and the view outside changed.

[Sparrow]

All you need do is reference it at wikipedia for the full definition...
http://en.wikipedia.org/wiki/General...s_(Larry_Niven)


I read Fleet of Worlds in which it is found a General Products Hull can indeed be breached...

In Fleet of Worlds, the characters tour a General Product factory and ask innocent-seeming questions of their tour guide, Baedeker. Baedeker reveals (apparently unintentionally) that the manufacturing process is extremely sensitive to gravity and impurities, that the hulls are constructed from a single supermolecule constructed using nanotech, and their strength is reinforced by an embedded power plant that reinforces the inter-atomic bonds. These facts provide the clues that allow them to later destroy a GP Hull from the inside and survive.

btw, if you haven't already done so, Fleet of Worlds is quite a good read, better in fact than Ringworld.

[Omphalos]

"Embedded" might refer just to the powerplant inside the hull, and not some mitochondria sized plant. These hulls could also be destroyed by antimatter. One of the short stories established that.

There were two ships in Ringworld. Shaeffer's Long Shot and the Lying Bastard. I think the Long Shot was a type 4 (large sphere) and the Liar was the tapered, wasp-waisted #2 (?) type hull. Not sure on those numbers, obviously.

[Dave]

Originally Posted by Sparrow

btw, if you haven't already done so, Fleet of Worlds is quite a good read.

I'll second that, and you have just reminded me that the sequel should now be out in paperback - Juggler of Worlds.

I don't have much to add to what has been said. The Puppeteer technology was meant to be beyond our comprehension in the earlier books, but I like the partial explanation given in Fleet of Worlds.

[pyan]

Originally Posted by Omphalos

These hulls could also be destroyed by antimatter. One of the short stories established that.

Yes, that's Flatlander, a Beowulf Shaeffer short story published in the Neutron Star collection. Highly recommended as an introduction to Niven - IIRC, it was the first one I ever read, before even Ringworld.

[Vault Dweller]

Originally Posted by ghost8772

Wasn't the ship in Ringworld a GP hull? what I remember the hull was fairly strong, but not impervious, they had it set up that a stasis field was set up over the continuous hull, wings and external equipment and thrusters,were outside that line. if something threatened the integrity of the hull, the stasis field engaged and would not allow anything inside the outside line of the atoms comprising the hull. its how they landed initially on the ringworld, and if I recall correctly, the ship in ringworld engineers ended up buried in the world itself following the same trend. something happened to the ship, when it crashed the stasis field energised and once everything was "safe" again it turned off. to the occupants it felt like they blinked and the view outside changed.

It's not because the GP hull isn't impervious that the Puppeteers have stasis fields installed in the ships.

First of all, a Puppeteer does not need any reason to add extra safety features, they would just do it. But the reason for the stasis field is because even though the hull is indeed impervious, the contents of the ship are still subject to harm. You send the ship thousands of mph into a surface and it won't take a scratch, but everything inside of it will still be smushed. The stasis field protects everybody inside from those dangers.

It is proven though that antimatter tears a GP hull's one molecule apart instantaniously. That would be the only thing that could harm it.

[Dave]

I'm now currently reading Destroyer of Worlds and there is a little summary of the ways in which a GP hull could still fail to protect you:

• Hit something hard enough and passengers become stains on a still unblemished hull.
• Antimatter in sufficient quantities - but antimatter is scarce - the trick was to find enough.
• Visible light passes through the hull - a laser beam held on target long enough will vaporise any painted coating, overcome any anti-flare shielding and pour unabated through the still intact hull.
• Each GP hull is a single artificial molecule - intermolecular bonds massively reinforced by an embedded power plant. A lucky shot or a nearby stationary target and the power plant can be fried - air pressure alone can then burst the weakened hull.
• And there is at least one other way - known to Puppeteers only - which they used to destroy, all at once, every GP hull in the New Terra Navy.

[Nik]

IIRC, there were three standard types of GP hulls-- the Big Sphere for mega-lifting or scouting galactic centres, the Fat, Slightly Flattened Cylinder for commercial purposes and the Wasp-Waist for yachting, couriers and hybrid craft.

Yup, single molecule reinforced by 'force field': My incomplete understanding is that the power supply(s) may be concealed within hull thickness by an optical trick, via the refractive index.

( Like the infamous, self-refilling shot-glass with a mini-gate concealed in base... ;- )

A 'visible' laser could get through, zapping occupants and *possibly* reflecting internally until the power supply cooks. Getting too close to sufficient anti-matter (Strangest Planet ?) would disintegrate the hull *suddenly*, and the Monsters of HyperSpace could chow down on the hull as-is.

Uh, I never did find out if the RingWorld widget that made their Unobtanium air-walls walk-through would de-polymerise a GP hull...

Plus whatever back-door(s) the paranoid Puppeteers build in...

[pyan]

Originally Posted by Nik

IIRC, there were three standard types of GP hulls-- the Big Sphere for mega-lifting or scouting galactic centres, the Fat, Slightly Flattened Cylinder for commercial purposes and the Wasp-Waist for yachting, couriers and hybrid craft.

There were four sizes - there's also a sphere about 75cm in diameter, used for satellites and probes, etc.

[sffmdw45]

Originally Posted by Nik

Uh, I never did find out if the RingWorld widget that made their Unobtanium air-walls walk-through would de-polymerise a GP hull...

You should read /Destroyer of Worlds/, where this question is obliquely addressed.

-Max