The Ringworld of Nevhonna 4

The Ringworld of Nevhonna 4 are fictional megastructures and superweapons in featured in the Maveric Universe They are referred to as "Installations" by their AI monitors, and are collectively referred to as "the Array" by the installations' creators, the Sidairians as cheaper version of a dysonsphere,for colonist to inhabit.

Design and development
The term "megastructure" refers to artificial structures where one of three dimensions is 100 kilometers (62 mi) or larger. The first use of a ring-shaped megastructure in fiction was Larry Niven's novel Ringworld (1970). Niven elaborated on his design as an intermediate step between Dyson Spheres and planets, where a ring with a radius of more than 93,000,000 miles (150,000,000 km) and 1,000 miles (1,600 km) wide; these are dimensions far exceeding the ringworlds found in the Halo series, which feature radii of 5,000 miles (8,000 km) As seen in the games, Halo installations feature a metallic exterior, with the interior of the ring filled with an atmosphere, water, plant life, and animal life. A massive wall on the sides of the structure, combined with the centrifugal force produced by the ring's rotation, keep the environment from leaking into space. What appear to be docking ports and windows dot the exterior surface, suggesting that a fraction of the ring structure itself is hollow and used for maintenance, living, and power generation.

The Ringworld is described as having a mass approximately equal to the sum of all the planets in our solar system. The adventurers surmised that its construction consumed literally all the planets in that original system, down to the last asteroid and/or moon, as the Ringworld star has no other bodies in orbit. In Ringworld's Children it is additionally explained that it took the reaction mass of roughly 20 Jupiter masses to spin up the ring; thus either the combined mass of the planets of the original system was that much larger than our solar system's, or there was other source material.

Variations
=== "Ringworld" has become a generic term for such a structure, which is an example of what science fiction fans call a "Big Dumb Object", or more formally a megastructure. Other science fiction authors have devised their own variants of Niven's Ringworld, notably Iain M. Banks' Culture Orbitals, best described as miniature Ringworlds, and the ring-shaped Halo structure of the video game Halo. ===

==== The construction of a ringworld remains firmly in the area of speculation. If such a structure were built it could indeed provide a huge habitable inner surface, but the energy required to construct it, set it rotating, and keep it stabilized is so significant (several centuries' worth of the total energy output from the Sun) that without as-yet unimagined energy sources becoming available, it is hard to see how this construction could ever be possible in a time frame acceptable to humans. ====

==== The tensile strength of the material required would be on the same order as the strong nuclear force, according to Niven – since the artificial gravity is the same as normal gravity, the structure is comparable with a bridge with an extremely long span; nothing even remotely strong enough is known to exist in nature. In Niven's Ringworld novels, the material – which he calls scrith – is said to have been artificially produced through the transmutation of matter into the required substance. (This merely gives a name to the sufficiently advanced technology that would have to be used.) In later novels the "transmutation" idea is simply discarded and the construction method of scrith left open, although one engineer is able to use nanotechnology to weave new scrith into meteor punctures. ====

==== A ringworld design requires active stabilization, because it is not in inertial orbit. Though the ring itself is rotating at 1,200 km/s (to approximate Earth gravity), the center of mass is stationary — in fact, it is at an unstable equilibrium, roughly comparable to a small sphere balanced on top of a pin. ====

Thus, large thrusters must be incorporated into the design to keep it centered about its star. This point gave Niven some difficulty after he published his first Ringworld novel; he was deluged with letters pointing out that "the Ringworld isn't stable" and dedicated the first sequel to a resolution of this problem. He notes in the dedication of Ringworld Engineers that at the 1971 World Science Fiction Convention, MIT students crowded the hotel hallways chanting "The Ringworld is unstable!" In this first sequel, he also tackled how to prevent all the soil from ending up in the oceans. In the fourth book in the series, Ringworld's Children, he creates backplot explanations for several of the imperfections in his original design of the Ringworld — and wholly glosses over others, such as that Louis Wu is worried about his dietary intake of salt since only the Great Oceans are described as being saline.

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A further point of instability comes from the inclusion of the two ‘Great oceans’; large bodies of water each many times the mass of the earth. =====

The original story had the builders place the two large masses of water on opposite sides of the structure in order to counterbalance each other; however this counterbalancing effect would only have been valid under the original novel’s contention that the ringworld was ‘in orbit’ with the centrifugal force being balanced by the pull of gravity of the sun.

Since we now know that that is not the case and that the whole structure is supposedly held rigid by centrifugal force alone, the effect of the mass of the two oceans would instead be to deform the structure away from its stable circular shape (imagine a loop of string with 2 heavy weights at opposite positions; when spun the two weights will fly apart under centrifugal force pulling the loop into a straight line with the weights at either end).

We can assume from this that scrith has a much higher density than water, making the weight of the oceans negligible (the discretion to place them at opposite positions on the loop can be considered an artistic one).

==== To provide an approximation of the day–night cycle common to planets, Niven's Ringworld was also provided with a separate ring of "shadow squares" linked together (by "shadow square wires") in a ring close to the star, rotating at slightly faster than the Ringworld's spin, providing a lot of twilight, as well as a day-night cycle. This is not the perfect match for a planet however, as there is no sunrise or sunset in Ringworld, and when not covered by a shadow square, the sun is always at high noon. These absorb a huge amount of sunlight energy, which is beamed to the Ringworld as its primary source of power. They are also not in inertial orbit, and must be actively stabilized as well. The shadow squares provide another of the imperfections "clarified" in Ringworld's Children, as five shadow squares of greater length, orbiting retrograde would provide a better day-night cycle, with less twilight. As revealed in Ringworld Engineers, the "shadow squares" also provide a shielding to the inner surface of the Ringworld when someone in the control room uses a magnetic field embedded in the Ringworld to fire the meteor defense system. ====