O'Neill Cylinders

[jeff_wilson]

Originally Posted by Brett

Yeah, I noticed. It's worse than that, actually, since I am going for a diameter, not radius, of 20 km. And the fact that my end caps are hemispheres rather than disks is not going to be anything like enough to save me. In fact, the inequality is rather discouraging. It looks to me as though cylinders have to be so short in relation to their length that roofing over the cylinder floor would be cheaper than capping the ends. That produces a Stanford rather than an O'Neill.

Which means I'm stuck with active stabilization, I think.

I see two ways of giving your self more wiggle room:

1) Ditch the precession and use mirrors to keep the sunlight aimed in.

2) Increase the moment arm with some sizeable masses on spokes. These needn't be entirely deadweight, they can be high-gravity applications like wastewater separation or detention. Or if the yoke technology was realistic, you could mount the spokes on coaxial bands like barrel hoops and have them spinning at slower rates for the same apparent gravity, less gravity for invalids and sybarites, or adjustable if you like.

[Agemegos]

Originally Posted by jeff_wilson

1) Ditch the precession and use mirrors to keep the sunlight aimed in.

I never liked the look of the precession. And I think that natural lighting is overrated at the tech level I'm contemplating (GURPS TL 10, basically). I was going to sting a cable down the middle with some dampening to stop it from twanging or doing anything embarrassing like that and hang electric lights on that.

2) Increase the moment arm with some sizeable masses on spokes. These needn't be entirely deadweight, they can be high-gravity applications like wastewater separation or detention.

Good idea. I wonder whether plants (and maintenance workers) can stand high gravity in the agriculture/oxygeneration rings?

[jeff_wilson]

Originally Posted by Brett

I never liked the look of the precession. And I think that natural lighting is overrated at the tech level I'm contemplating (GURPS TL 10, basically). I was going to sting a cable down the middle with some dampening to stop it from twanging or doing anything embarrassing like that and hang electric lights on that.

I'd think the axis would be naturally efficient as a general platform for large parts of all the systems needed to keep the interior livable, so that you'd probably want at least a semirigid lattice around an end-to-end transport system for solids as well as conduits for fluids, power, and bandwidth.

[Agemegos]

Originally Posted by jeff_wilson

I'd think the axis would be naturally efficient as a general platform for large parts of all the systems needed to keep the interior livable, so that you'd probably want at least a semirigid lattice around an end-to-end transport system for solids as well as conduits for fluids, power, and bandwidth.

Anything fifty kilometres long is a cable.

[Agemegos]

Okay, so the Imperial Capitol in FLAT BLACK is going to be 20 km in diameter and 60 km long including hemispherical end-caps. Lit by a string of lights down the middle. It has a usable interior surface of nearly 3,000 square kilometres, making it larger than Luxembourg or Delaware. Most offices, residences, and such facilities can be under "ground", or rather, the interior can consist largely of a huge roof garden. Places with view windows will do best on the slopes of the end-caps.

With a population of, say 500,000, the Imperial Senate buildings and residences for a thousand senators and staff, can we spare room for a military academy? One campus of the military academy? Or should all military academies be put where cadets can bang off guns safely?

What's a good level of centripetal acceleration ("gravity") for such a place? 10 ms^-2 is a "standard gravity". 9.81 ms^-2 recalls the gravity of Old Earth. About 8.5 ms^-2 would be about average for people growing up in the colonies (weighted by population) and very convenient in GURPS rules. 10 ms^-2 would require that the place rotate at about 0.3 RPM.

[sir_pudding]

Originally Posted by Brett

Or should all military academies be put where cadets can bang off guns safely?

Only a small portion of Imperial officers training involves personal weapons, and a lot of that can be handled in VR. I'd think live fires are infrequent enough to warrant field trips to the range.

[Agemegos]

By the way, does anyone know of a suitable ray-traced (not artist's impression) interior shot for something like this? I'd like one without Island Three-style longitudinal windows, and without the Rama-style spikes in the end-cap.

I already have these on Youtube:

• http://www.youtube.com/watch?v=swMAjaQ5AsQ
• http://www.youtube.com/watch?v=uhola...eature=related
• http://www.youtube.com/watch?v=rPj4y...eature=related

[dcarson]

An experiment involving several generations of chickens and a centrifuge showed that they are healthier when raised under higher gravity. So farming should be OK.

Having your cadets train under varying g levels would also be useful.

[Agemegos]

Originally Posted by dcarson

An experiment involving several generations of chickens and a centrifuge showed that they are healthier when raised under higher gravity. So farming should be OK.

Having your cadets train under varying g levels would also be useful.

Indeed. At minimum they need to train in free-fall, at lunar/asteroidal gravities, in gravity not above 0.65 gee, in gravity not below 1.07 gee, and in gravity about 0.86 gee. They also have to train extensively in a spaceship or ship-like habitat, on a moon or asteroid surface, and in several different planetary environments including urban, farmland, forest, and open land. And at sea, and underwater. Multiple campuses will be required.

[jeff_wilson]

Originally Posted by Brett

Indeed. At minimum they need to train in free-fall, at lunar/asteroidal gravities, in gravity not above 0.65 gee, in gravity not below 1.07 gee, and in gravity about 0.86 gee. They also have to train extensively in a spaceship or ship-like habitat, on a moon or asteroid surface, and in several different planetary environments including urban, farmland, forest, and open land. And at sea, and underwater. Multiple campuses will be required.

My BLACK OPS players pointed out that other than the gravity variations, most of these could be had at a certain facility near Orlando, Florida.