Larry Niven's "Ringworld" (novel): An interesting artificial space habitat

The only thing interesting in this novel for me was the description of Ringworld habitat - something that occupies may be 10% of the story, & because of which I will likely seek out the sequels.

Of the parts that don't describe Ringworld, first third is just preparation for story; later two thirds is the familiar post-apocalypse story you have seen in dozens of cold war nuclear holocaust novels.

This is not always a logical story. You will need to sometimes suspend credulity.

Thing that often put me off through the story was tangents - just too many of them, & attempt to put in every conceivable technology & plot popular in sf stories! It's far more complex story than it needed to be. This cannot be the best story by Niven; or may be I will be better off sticking to his short stories.

Story summary.

Time is several thousand years into future, or may be several tens of thousands. Humans occupy worlds on many star systems, & have been in contact with several sentient alien races, among them "Pierson's puppeteers", & Kzinties. These two play a role in this story - of unnecessarily complicating it.

Nessus, a puppeteer, has recruited 3 members for an expedition:

1. Louis Gridley Wu, a 200 year old human male who is physically young because of "boosterspice" doses! I wonder if boosterspice is motivated by the spice in Herbert Spencer's "Dune" (but I haven't read Dune beyond initial few pages)?
2. Teela Jandrova Brown, a 20 year old human female. Her qualification for expedition is: she has been bred genetically to be "lucky"!!!
3. "Speaker-To-Animals", a Kzinti diplomat on earth.

About a quarter of the way through the story, the recruitments have been done, explorers have traveled to puppeteer world some 200 light years from earth, & we are told the purpose of exploration.

Puppeteers have discovered a massive artificial structure ("Ringworld") that is obviously a habitat of some sentient lifeform far more advanced than anything known - relatively close to current location of moving-at-near-lightspeed puppeteer world; see details of the structure below. Why puppeteer world is moving so fast is a separate but unimportant subplot.

Explorers will go to Ringworld to make first contact, & learn what they can about these new aliens.

About a third of the way through the story, they will crash accidentally on Ringworld. All attempt to establish communications with locals have failed - no one responds. To get off Ringworld, they need help. Explorers will travel a lot of local territory in search of help, & will eventually be able to leave after much drama. Later two thirds is the story of their local travels.

What they find here are humans! But living a primitive life - no signs of intelligence that created Ringworld. They will later meet others descended from "Ringworld Engineers" stock - their ancestors had built the world - only they also appear to be humans, & are also living primitive life! I could not figure out how exactly the Engineers are related to humans.

Near end, we learn the reason of end of their civilization - & it's totally crazy. Turns out - they had multi-storied buildings hanging in the air, above the ground-based cities - hanging by some kind of levitation method. There was a big power failure that brought these hanging buildings crashing down on cities - killing off pretty much everyone competent to fix things!

There is an explanation of power failure too - some kind of bug eating through the generation machinery; what I failed to understand was how could the power failure have occurred simultaneously over whole of Ringworld - with a habitable area that is millions of times that of earth!

There is a happy ending for explorers - they are able to escape, but in a very irresponsible manner - dooming a lot of locals to major injury by spreading miles upon miles of dangerous cutting thread on Ringworld surface.

Teela will not return - she has found her love there. And there is a new passenger - Halrloprillalar (shortened to "Prill"), of Ringworld Engineer stock - lady love in the life of Louis, to replace Teela.

The Ringworld Habitat.

"Take Christmas ribbon, pale blue and an inch wide, the kind you use to wrap presents. Set a lighted candle on a bare floor. Take fifty feet of ribbon, and string it in a circle with the candle at the center, balancing the ribbon on edge so that the inner side catches the candlelight."

Only the ribbon is a million miles wide rather than an inch, & "about six hundred million miles long". Ring is located "more than ninety million miles" from its sun (about the distance of earth from Sun). It is rotating about its sun at "770 miles per second" - giving surface gravity "a touch less than earth's". "It massed a little more than the planet Jupiter". I suppose some kind of artificial means are used to stabilize the ring so sun always is at its center; book doesn't mention anything about stabilization.

Habitable surface faces sun, & has thousand miles tall mountains at the rim - so you won't fall off the edge, & also to contain the atmosphere. At the top of the mountains is long distance surface based transportation system - some kind of non-mechanical rail.

When seen from far, the ring is "laid out in rectangles: a long strip of glowing baby blue followed by a shorter strip of deep, navy blue, followed by another long strip of light blue." This is the "thirty hour day-night cycle" - shadows cast by a second faster rotating ring much nearer the sun that is a bunch of "Twenty rectangular" dark plates strung together with tough thin wires. The inner ring rotates in an elliptic orbit - changing the length of day & night at a place on habitable surface, giving seasons.

Inner plates also generate power from sunlight, & beam it to habitable surface. These power beams are now down. When the receivers at outer ring shut down during the event that lead to collapse of civilization, transmitters stopped sending. Apparently, transmitters can sense the state of receivers, but you can not start transmission by remote command - you must physically travel to inner ring. But transmitters are presumably still ok - if someone could fly there & start them, & if the receivers were made functional. I wonder if this fact will be used in one of the sequels.

Total habitable surface area is "Six hundred trillion square miles" - "three million times the surface area of the Earth. It would be like having three million worlds all mapped flat and joined edge to edge. Three million worlds within aircar distance. That'd solve any population problem."

About half the habitable surface is covered with shallow water bodies - including two oceans on opposite sides of the rim that are each bigger than total surface area of earth!

Ring floor comprises of very tough foundation material. It is so tough - it stops 40% of all neutrinos! It's layered with 40(?) feel of soil.

"There was an atmosphere on the ring's inner side. Spectroanalysis showed the air to be as thick as earth's, and of approximately the same composition: definitely breathable to man and kzin and puppeteer."

There are also rivers, & jungles.

Habitable ring has "average temperature of 290 degrees absolute, ... the inner as well as the outer surface of the ring." Optimum for humans.

In the system of this sun "there was nothing at all but the ring itself. No planets, no asteroids, no comets... They cleaned it out... They didn't want anything to hit the ring." Automatic systems to attack anything threatening Ringworld still operate.

In the parts our explorers travel, there have been at least two punctures through the foundations by meteor impact - and there is no one around now who knows anything about fixing it. One was created by impact of a body about the size of earth's moon - that elevated the surface contours around puncture to a thousand mile (?) tall mountain - with puncture well above atmosphere - so no air leak there; it's called "Fist-of-God" by locals.

Another is a smaller one, & is the location of a permanent air maelstrom - like the eye of Jupiter; air has been leaking through it for god knows how long! But Ringworld is big; it won't become unbreathable anytime soon.

Trivia.

1. Book keeps using the term "tanj!" ("There Ain't No Justice!") where you would normally use "damn!"

See also.

1. A not-to-scale illustration of Ringworld, seen from outside the system.
2. Some illustrations of puppeteers.
   

Fact sheet.

"Ringworld", novel, review
First published: 1970.
Rating: B
Winner of Hugo Award 1971 in novel category.
Winner of Nebula Award in 1970 in novel category.

Series.

1. Ringworld
2. The Ringworld Engineers
3. The Ringworld Throne
4. Ringworld's Children