Tom Kalbfus
Mongoose
This is the Constellation Centaurus, where the Centauri Ringworld gets its name, this is not an actual grouping of stars together, they are only seen that way from the Earth, the most famous member of this group is also the closest star system to Earth besides our Solar System, on this map it is labeled Rigel Kentarus, it is the left front knee of the centaur, in this imagining, the Alpha Centauri System (Rigel Kentaurus) has no habitable planets, it has planets, but no habitable ones. the one known planet in the system today is Proxima Centauri b, it is a super-Earth sized planet, and has a high gravity field between 1 and 2 G, and it has a very thin atmosphere, most of it having been blasted away by the frequent stellar flares of Proxima Centauri. Beyond Proxima Centauri are two stars.
They are labled here as Alpha Centauri A and Alpha Centauri B, in this diagram Alpha Centauri B is the wrong color, it should be redder that Alpha Centauri A, not whiter! Be that as it may, this diagram is a fairly accurate representation of the system as it exists today. In this universe, there are no FTL drives, no grav vehicles, no psionics, it is a very hard science fiction universe, but on the otherside of the ledger, artificial intelligence surpasses human intelligence in the second half of the 21st century. Humans build bases on the Moon, they settle Mars and the asteroids, and then the machines surpass them, and then history as we know it ceases to be, no one precisely knows what happened in the years between 2050 AD and whatever era in which the Centauri Ringworld was created. It appears the builders were machines, the technological descendents of the human race. No alien extraterrestrial civilizations were ever discovered, so our technological descendents, the machines decided to create some, they created a vast computer around Alpha Centauri A and a ringworld, this one 1.24 AU in radius and rotating once every 10 days to produce 1-G of gravity.
Most of the machines that were free willed decided to migrate to the future when the Universe would be much older and colder, so they went into sleep mode, leaving the rest of the here and now to humans and various aliens created in a simulated universe which is the OTU, although the inhabitants don't know they are part of a simulation. As far as they know their timeline departed from the true timeline early in the 21st century, and some easy technological discoveries we're made regarding the Jump Drive, and artificial gravity, and some people developed psionic powers, all simulated by the computer. There were no true humans left when our technological descendents turned their sites on the stars, as they still considered themselves "human" even though they were no longer biological, they decided to build a ringworld in the neighboring star system, rather than mess with the planets of their home system. Oh they terraformed Mars and Venus, they appreciated the beauty of nature and all of that, but their real major construction began in the Alpha Centauri System where they took apart Alpha Centauri B to build a ringworld.
Alpha Centauri B has 0.907 the mass of our Sun, and 98% of that is hydrogen and helium, and the remaining 2% is other stuff, that means it has 299,310 times the mass of Earth or more importantly it has 941 times the mass of Jupiter, about 18.8 Jupiter's worth of material that is heavier than either hydrogen or helium. Larry Niven said we need about 1 Jupiter's mass of material to build a ringworld, I think 18.8 jupiter's worth more that satisfies that requirement. The other 922.2 Jupiter masses is hydrogen and helium, the bulk of this fills a hollow tube just outside of the ringworld, called the stationary ring, the walls of this tube are made up of some of the 18.8 Jupiters worth of mass, at least 1 Jupiter of mass is reserved to build the ring world itself. The stationary ring consists mostly of hydrogen tanks filled with hydrogen. This hydrogen has mass and weight under the stellar gravity of Alpha Centauri A and the material of B, this compression is set to exactly equal the outward force of the rotating ringworld trying to fly apart. the fusion rocket engines on the outside of the stationary ring keep it centered around Alpha Centauri A and since the ringworld is nested on the inner curve of the stationary ring and held to its circunference as it spins by magnetic field, it stays centered around the star as well.
There are 11 very long rectangular shadow squares orbiting the central star, orbiting once every 100 days while the ringworld rotates once every 10 days, so for every 10 rotations of the ringworld, the shadow squares rotate once, or they complete one tenth of a rotation for every complete rotation of the ringworld. the fusion reactors on the stationary ring power the reaction control rockets of that ring and the remaining power runs a computer that simulates charted Space, and a number of historical eras and prehistorical eras of Earth. There are gates on the surface of the ringworld that allow the downloading of simulated objects into actual atoms and material objects on the ringworld surface, one of those simulations is of Charted Space, it is a very big simulation taking up a considerable amount of computational resources, some smaller simulations are of Earth at various eras in the past, one of the simulations is of the Earth today, there is a gate leading from what is the simulated Bermuda Triangle to the ringworld floor, as of the simulated year of 2018, in the middle of July, that gate opens, and a number of modern Earth people download themselves onto the ringworld floor and have to decide what to do about it. Another gate is a simulated ringworld in the OTU, a spaceship that approaches too close to it, gets downloaded onto the actual floor of the ringworld, but as it depends on fictional technology to fly in its fictional universe, it needs something else to get around in the real Universe. The fusion reactors of the spaceships work just fine, the maneuver and jump drives not so much, and neither do grav vehicles or artificial gravity, that is the situation.
