Ringworld

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Title Ringworld

Cover of first edition (paperback)
Author	Larry Niven
Country	United States
Language	English
Series	Ringworld
Genre(s)	Science fiction novel
Publisher	Ballantine Books
Released	1970
Media type	Print (Hardcover & Paperback)
ISBN	ISBN 0-345-02046-4
Followed by	The Ringworld Engineers, 1980

Ringworld is a Hugo and Nebula award-winning 1970 science fiction novel by Larry Niven, set in his Known Space universe. The work is widely considered one of the classics of science fiction literature. It is followed by three sequels, and it ties in to numerous other books in the Known Space universe.

Contents 1 Plot summary 2 Concepts 3 Ringworld engineering 4 Trivia 5 Sequels and adaptations 6 See also 7 External links

[edit] Plot summary

In the year 2855, four adventurers (two human and two aliens) explore a mysterious "ringworld": an enormous, artificial, ring-shaped structure that surrounds a star. The story is set in an extremely technologically advanced universe, where instant teleportation and nigh-indestructible spacecraft hulls are commonplace.

The character Nessus is a Pierson's Puppeteer, a species with the most advanced technology in Known Space. Being descended from herbivorous herd animals, their morality is based on cowardice: the ruling class is known as they-who-lead-from-behind, and the supreme leader is called the Hindmost. Puppeteers who display any signs of bravery are considered insane by their peers, and in fact are insane; bravery is accompanied by other symptoms of ill mental health, such as manic-depressive cycles and paranoia.

Essentially xenophobic, only a very small minority of Puppeteers interact with "potentially dangerous" alien species, usually only in cases where they need to hire mercenaries to handle risky situations which they themselves cannot. Only insane puppeteers are ever employed to arrange such matters; in fact sane puppeteers never leave their homeworld, being distrustful of space travel, among other things.

Nessus, being a "mad" Puppeteer, is given the task of assembling a team to explore the Ringworld, to see if it poses a threat to his species.

The main protagonist is Louis Wu, a periodic adventurer-cum-genius in the midst of celebrating his 200th birthday. Despite his age, he is in perfect physical condition due to a combination of superior genetic makeup, advanced medical technology and boosterspice, a drug that extends human life. He extends his birthday by teleporting ahead of the terminator from party to party across Earth, but it so happens that he is bored with life and eager for new challenges, so Nessus has little difficulty recruiting him.

Speaker-to-Animals is a Kzin, a ferocious felinoid predator species which has, in the recent past, fought a series of wars with humanity, losing every time because of a tendency to attack before being quite ready. He is recruited as the mission's security chief.

Speaker-To-Animals said one thing more before he turned back to his table. "Louis Wu, I found your challenge verbose. In challenging a kzin, a simple scream of rage is sufficient. You scream and you leap."

Finally, Teela Brown is a young human female whose role in the mission is not immediately clear. But Puppeteers do not do anything without a very good reason, and her significance is revealed as the plot unfolds. Teela Brown is the result of selective breeding for luck, which generally helps her and her descendants, but not necessarily her companions

When their ship crash lands on the Ringworld, after striking one of the near-invisible shadow-square wires, the adventurers must set out to find a way to get back into space. They cross vast distances, witness strangely evolved ecosystems, and interact with some of the Ringworld's varied primitive civilizations. They attempt to discover what caused the Ringworld's inhabitants to lose their technology, and puzzle over who created the Ringworld and why.

[edit] Concepts

In addition to the two aliens, Niven includes a number of concepts from his other Known Space stories:

• the Puppeteer's General Products hulls, which are impervious to any known force except visible light and gravity, and cannot be destroyed by anything except antimatter.
• the Slaver stasis field, which causes time in an area to stand still; since time has for all intents and purposes ceased for an object in stasis, no harm can come to anything in its field.
• the idea that luck is a genetic trait that can be favored by selective breeding.
• the tasp, a device that induces a state of extreme pleasure in the pleasure center of the brain at the push of a button; it is used as a non-harmful method of debilitating its target and is extremely addictive. If the subject cannot, for whatever reason, get access to the device, intense depression can result, often to the point of madness or suicide.
• boosterspice, a drug that extends human life to near immortality.
• Impact armor, a flexible form of clothing that hardens instantly into a rigid form stronger than steel when rapidly deformed (for example, by the impact of a projectile such as a bullet).
• Hyperdrives allow for faster-than-light travel, but at a rate slow enough (1 light year per 3 days) to keep the galaxy vast and unknown; the new Quantum II Hyperdrive, developed by the Puppeteers but not yet released to humans, can cross a light year in just 1.25 minutes.
• Near instant point-to-point teleportation is possible with transfer booths (on Earth) and stepping disks (on the Puppeteer homeworld); on Earth, people's sense of place and global position has been lost due to instantaneous travel; cities and cultures have blended together.

A theme well-covered in the novel is that of cultures suffering technological breakdowns who then proceed to revert to belief-systems along fundamentalist and/or religious lines. Most societies have forgotten they live on an artificial structure, and now attribute the phenomena of their world to divine power.

[edit] Ringworld engineering

Ringworld parameters

Radius	0.95×108 miles (~1.5×108 km) (~1 AU)
Circumference	6×108 miles (~9.7×108 km)
Width	0.997×106 miles (1,600,000 km)
Height of rim walls	1,000 miles (1,600 km)
Mass	2×1027 kg (1.8×1024 short tons) (1,250,000 kg/m², e.g. 250 m thick, 5,000 kg/m³)
Surface area	6×1014 sq mi (1.6×1015 km²); 3 million times the surface area of Earth.
Surface gravity	0.992 gee (~9.69 m/s²)
Spin velocity	770 miles/second (~1,200,000 m/s)
Sun's spectral class	G3 verging on G2; "barely smaller and cooler than Sol".
Day length	30 hours
Rotational time	7.5 Ringworld days (225 hours, 9.375 Earth days)
On Ringworld, time longer than a day is measured in falans, with 1 falan being 10 turns or 75 Ringworld days (93.75 Earth days), so 4 falans is slightly longer than 1 Earth year.

The "Ringworld" is an artificial ring about one million miles wide and approximately the diameter of Earth's orbit (which makes it about 600 million miles in circumference), encircling a sol-type star. It rotates, providing an artificial gravity that is 99.2% as strong as Earth's gravity through the action of centrifugal force. Ringworld has a habitable flat inner surface equivalent in area to approximately three million Earth-sized planets. Walls 1000 miles tall along the edges retain the atmosphere. The Ringworld could be regarded as a thin, rotating slice of a Dyson sphere, with which it shares a number of characteristics. Niven himself thinks of the Ringworld as "an intermediate step between Dyson spheres and planets." To this end, one must understand (spoiler alert!) that in the context of the books the Ringworld was described to have an approximate mass equal to the sum of all the planets in our solar system, and that the adventurers surmised that when the ringworld was built that it was made literally using all the planets in that system as their source of material 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 the combined mass of the planets of the original system was that much larger than our solar system's.

"Ringworld", or more formally, "Niven ring", 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 series of the same name.

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 and set it rotating 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.

Furthermore, the tensile strength of the material required would be on the same order as the strong nuclear force^{[citation needed]} (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.

Additionally, a ringworld design requires active stabilization, because it is not in inertial orbit. Though the ring itself is rotating at 1200 km/s (to approximate Earth gravity), the center of mass does not move at all. 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. 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.

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.

The "Control Room" is a vast maze of rooms contained in the hollow space under the "Map of Mars". In order to create the rarefied atmosphere on Mars, the "Map of Mars" is lifted 20 miles above the main Ringworld surface creating a 1,120,000,000 cubic mile cavity. The Control Room contains living space for thousands of Pak Protectors, as well as space to grow the "Tree-of-Life" plants to support this many Protectors. Other rooms in the cavity support such features as the "Meteor Defense System", which uses the superconductor grid embedded in the scrith foundation material to manipulate the magnetic field of the Ringworld's sun to create a solar flare; it uses this to generate a powerful gas laser, which is capable of destroying everything in its path.

[edit] Trivia

• In the first edition of Ringworld, Louis Wu tries to extend his birthday by travelling (through instantaneous transfer booths) eastbound around the earth. This would have shortened his birthday, not prolonged it. In later editions, he travels westbound.
• Due to the book's popularity, many fans have pointed out scientific inaccuracies found in it and its sequels. At the 1970 World Science Fiction Convention there were MIT students in the halls chanting, "The Ringworld is unstable! The Ringworld is unstable!", prompting his writing of The Ringworld Engineers. A quote from Larry Niven's answer: "Did the best that I was able ... hence, attitude jets."
• Impact armor is being tested during the 2006 Winter Olympics, composed of a synthetic material called d3o (see here).
• Many references are made by Louis to Finagle's Law. He also mentions Occam's Razor.

[edit] Sequels and adaptations

The novel Ringworld has been followed by three sequels, The Ringworld Engineers (1980), The Ringworld Throne (1996), and Ringworld's Children (2004).

In the 1980s a role-playing game based on this setting was produced by Chaosium named RingworldRPG.

Tsunami Games released two adventure games based on Ringworld, "Ringworld: Revenge of the Patriarch" in 1992 and "Return to Ringworld" in 1994.

In 2004, the Sci Fi Channel reported that it was developing a Ringworld miniseries [1]. Larry Niven reported in 2001 that a movie deal had been signed and was in the early planning stages, with rumors circulating that James Cameron might direct [2]. There have also been many abortive attempts to adapt the novel to the screen.

The plot of the first-person shooter Halo for the Microsoft Xbox also takes place on a ringworld-like structure. Given its dimensions (10,000 kilometers in diameter) it is more like Banks' Culture Orbitals than Niven's behemoth.

There is a Ringworld system tile created for the boardgame Twilight Imperium on BoardGameGeek[3].

[edit] See also

• Culture Orbital
• Planets in Science Fiction
• Known Space
• Megastructure
• Dyson Sphere
• Halo (megastructure)

[edit] External links

• A review of Ringworld
• Physical parameters of the Ringworld
• Ringworld Image from Bryce3D Gallery

Preceded by The Left Hand of Darkness by Ursula K. Le Guin

Nebula Award for Best Novel 1970

Succeeded by A Time of Changes by Robert Silverberg

v • d • e The Ringworld Series by Larry Niven
Ringworld | The Ringworld Engineers | The Ringworld Throne | Ringworld's Children