Bishop Ring

Bishop ring interior
Image from Arik
Bishop ring interior

Giant rotating orbital habitat, built of woven diamondoid/buckyfibre cable; these come in a range of sizes up to 2000 km in diameter and 500 km deep. The atmosphere is mostly retained by the centrifugal force of the spinning habitat, but to reduce losses further, most rings have a thin transparent membrane that seals the opening..

In the Information Age Forrest Bishop proposed this design of ring-shaped, open ended habitat, with the atmosphere retained by centrifugal force and tall atmosphere walls.

When carbon nanotube buckyfibre cable became readily available through nanofacturing techniques, the size of rotating habitats could be increased considerably. The largest rotating habitats possible using this material can be slightly more than one thousand kilometers in radius, depending on the mass of landscape included. Most rings are somewhat smaller than this for safety reasons.

Bishop Ring
Image from Steve Bowers
Rendell Bishop Ring

The ring is constructed from a coil or weave of carbon nanotube buckytube, formed into a short cylinder which is rotated to produce artificial gravity. Carbon Nanotube is sufficiently strong to support a cylinder of around 2000km in diameter with a rotation producing 1 gravity, but this leaves little margin for safety, and does not allow for the mass of the artificial landscape inside the ring. So most rings with Earth-like gravity are significantly smaller, from a few hundred up to a thousand kilometres in diameter. However a significant number of rings rotate more slowly, producing a lower gravity regime (a condition which is often popular with the inhabitants). The Arkab B necklace, for example, consist mostly of rings around 2000km across and an internal gravity of 0.8 gees or less.

This coil, or weave, is used to reinforce the main bulk of the ring, which holds atmosphere, soil, water, rocky substrate and habitations. In most versions of the Bishop Ring design, the bulk of the atmosphere is retained by a tall atmosphere wall ranging in height from 50km to 200km. Even 200km high walls are not high enough to prevent gradual atmosphere loss, so a thin transparent membrane or an airwall is used to cut atmospheric escape to negligible levels.

Bishop Ring.
Image from Steve Bowers
Koyukon 3, a bishop ring in the Terragen Federation. Bishop rings are used in many polities, and variation in their design details is commonplace
Generally the local star is permanently obscured from the point of view of someone standing on the ring-floor, to avoid constantly shifting illumination effects. This means the ring requires artificial lighting, generally provided by a central artificial sunlet called a luminaire. Power for this luminaire can be collected by photovoltaic cells on the outside of the ring; if the ring is distant from the star, the p-v arrays can be extended beyond the ring floor in both directions, and/or other sources of energy can be utilised.

Bishop Ring Ayen Jin
Image from Steve Bowers
Ayen Jin bishop ring in the Iota Piscium system is brightly decorated inside and out, in accordance with the exuberant style of that polity
In many locations, especially in the Zoeific Biopolity, these rings are grown organically, either in whole or in part. One clade associated with the bioconstruction of Bishop Rings is the vac-spider species Hobo Sapiens, who can extrude a range of specialised buckyfibre filaments from their spinnerets.

Bishop Ring Dennett
Image from Steve Bowers
Bishop Ring Dennet, a ring in the Negentropy alliance

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Development Notes
Text by M. Alan Kazlev, Todd Drashner and Steve Bowers
Initially published on 08 October 2001.

Additional Information
Forrest Bishop's original article here
Wikipedia Article
Bishop Rings