Monday, September 05, 2005


I just finished rereading the entire Ringworld series, including the new volume, which I had never read before. I'm not terribly visual when I read, but the descriptions Larry Niven gives in the Ringworld series are work well for me. I can look up and see the ringworld in my mind. For those of you who don't know, the concept is that, eventually, as we run out of living space, we'll take a gas giant the size of Jupiter or so, and, using fusion for both energy and materials, create a giant ring that we rotate around the sun. You'd put walls a thousand miles high on to keep the atmosphere in, spin in to give it "gravity", and place shadow squares in orbit above it to give day/night periods. A ringworld would have approximately 3 million times the surface area of earth, so it would be a long time till anyone felt crowded, and, since we don't need to include things such as the Sahara desert, the habital area would be still greater.

He never intended for there to be sequels. He wrote the first book, Ringworld placing it in the universe he created in the first short story he ever published, "The Man-Kzin Wars." People began flooding him with problems in the Ringworld he created, such as how to deal with solar flares, erosion, etc. From that, he wrote The Ringworld Engineers to work in the mechanics of the ringworld. With more suggestions, and criticism, he wrote The Ringworld Throne, to discuss the politics needed to keep the ringworld maintained. Finally, he wrote The Ringworld's Children, to tie up the loose ends in the previous three stories.

Anyway, in this rereading, after having just finished Thor Heyerdahl's Early Man and the Sea, I realized that I too had a problem with the Ringworld. (Why just enjoy when you can analyze?) Because the ringworld is flat, even though it is being spun, there is no coriolis effect. As a result, there is no return route for currents. In Earth's oceans, the water shifted west by the earth's rotation hits a continent, and is diverted towards the poles, where the coriolis effect is less severe, and can flow back to its starting point. On the ringworld, there would be an equal pressure everywhere, meaning that the water would pile up on the anti-spinward (the side opposite the ringworld's rotation) side and not be able to flow back. Thus the oceans, which are meant to provide the Ringworld's ballast, are unstable.

A second problem is that the oceans he describes are far too shallow for the storms he describes. Most of energy of a wave is contained under the surface, which is why you don't get a tsunami out of the local fishing hole. By making the oceans as shallow as he has, most of the power of the storm would be fed into the ringworld floor, which would spread the waves, but limit their total size, thus the fierce storms he describes wouldn't happen. A connected problem is that the draft of the ships he describes is too deep for the ocean. The huge ships used might as well have tracks that pull it along the bottom. Otherwise, they would have to be built broad and flat like a raft.

A third problem is that they cleared away all of the debris in the system to protect the ringworld from impacting comets, asteroids, etc. But that means that there are no tides. Without tides, especially in an environment without currents, the seas would rapidly become stagnant and liveless. Without life in the seas, the atmosphere of the ringworld would rapidly degrade. Though we can't create currents on a flat surface, by adding considerable bulk to the shadow squares in orbit above the ringworld, we could at least create tides.

Good thing I don't read more science fiction. I blazed through all of those books in two days.


Blogger Noumenon said...

I bet you could find a Usenet discussion of all of these points on Google Groups. I bet at least one of them can be fanwanked to make sense. I'm impressed you had time to think of this stuff while you were reading through in two days. I noticed no problem with the Ringworld at all, not even erosion.

6:19 AM  
Blogger Octavo Dia said...

In Ringworld's children, which I will not tell you about for fear of giving away a good portion of the plot, they suggested wobbling the ringworld around its axis, like the last few seconds of a coin spinning on the floor, in order to give the ringworld seasons. You would have to coordinate the shadow squares, or else make them a lot bigger, but it seems like it would work.

1:32 AM  
Blogger Hamlette said...

(Why just enjoy when you can analyze?)

Why analyze when you can just enjoy?

(I had to say it, I know you were waiting for me to.)

10:41 PM  

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