The Earth orbits our star, Sol, at a distance of roughly 93 million miles (150 million kilometers) — a distance we call an Astronomical Unit (AU). Our little rock is just under 8,000 miles wide (a bit over 12,000 km) and has a surface area (including oceans) of just under 200 million sq miles (510 million sq km). Depending on how you look at it, the Earth seems very large or very small.
What if, instead of a rock spinning around its star, it was a ring encircling it? Suppose the ring spun fast enough (770 miles per second) to create “gravity” on its inner surface? And suppose the ring was one-million miles wide and had walls 1000 miles high long both rims to keep air inside? Such a ring would have a surface area equal to about three-million Earths.
And what you’d have is Larry Niven’s Ringworld!
New Year’s Day I enjoyed two well-known, much beloved old favorite baseball movies. Today I sat down (stretched out on the couch, actually) to re-read another old and beloved friend: Ringworld (1970) by Larry Niven. When I finish, I’ll follow it up with the sequel: The Ringworld Engineers (1980).
Today, for Science Fiction Saturday, I’m just commemorating the start of a journey back to a place known to any fan of hard SF. Ringworld is as well-known (and much beloved) as either of the works known as “The Trilogy” (by Tolkien or Asimov, take your pick).
It is a true classic of science fiction!
The space wheel in the recent Elysium (which was a pretty decent movie I thought) invokes the Ringworld, albeit on a much (much!) smaller scale. But the open architecture — no “roof” with air trapped by the spin and walls — is exactly how the Ringworld works.
It’s not unlike how you can keep water in a bucket held horizontally if you spin around fast enough. You can even swing the bucket over your head, and the water will stay in it — so long as you keep the bucket moving in circles.
I wrote recently about John Varley’s Titan trilogy, and the wheel of Gaea also owes some passing allegiance to Niven even though Gaea was a closed, flattened tube (like a tire) — it was considerably bigger than any space station, though!
Niven combined the idea of habitable, spinning ring with a Dyson Sphere — an idea usually credited to Freeman Dyson in 1960, but which is actually based on a 1937 SF novel, Star Maker (other authors had similar ideas). The idea of a Sphere is that it completely surrounds its star, thus capturing the total output of that star.
Star Trek fans saw a Dyson Sphere is the Next Generation episode Relics, which also features the return of Engineer Scott and a reappearance of the old Enterprise bridge (and “it’s green”). It’s one of my favorites!
Niven’s Ringworld is similar to a Dyson Ring, which is just a band around the star. While that lets most of the star’s energy escape into space, it does considerably expand the habitable zone for those living in the system.
One of the very clever parts of Ringworld is the idea of the “shadow squares. Rotating about a third of the distance from the star to the ring (that is, at about 0.3 AU) is another ring. This one has 20 shadow squares wired in a circle. There is a gap between each that is over twice the length.The squares cast shadows — the Ringworld equivalent of night — onto the main ring. The size of the squares, the gaps, and the combined rotation speeds, all combine to create “nights” of nine hours and “days” of 21. Note that, during the “day” the sun is always directly overhead!
Ringworld, with a width of one-million miles, is so vast that one of its giant oceans contains islands that turn out to be scale-size replicas of Earth, Mars, and several alien planets inhabited by sapient species in Niven’s “Known Space” books. And these islands are small compared to the size of the “Great Ocean.”
One of the novel’s more intriguing characters is Teela Brown. She is the end result of a long, secret breeding program (by aliens manipulating events). The idea is that the aliens, for many human generations, have been breeding for luck.
Teela Brown is the luckiest being in all of Known Space. Nothing bad can ever happen to her (although her luck doesn’t always extend to her companions, plus it turns out that having bad things happen to you builds character)!
In any event, I’m eager to get back to the couch and the first novel. I’d just read the first line of the first chapter when I thought to myself, “Say, self… it’s Sci-Fi Saturday, and this beloved book would be nice to talk about! We could look for some artwork to share and connect it all to some other things. Might make a decent post, eh?”
Self quickly agreed that it sounded like a good idea, but wasn’t sure actually getting off the couch to do it was all that attractive. “Couch comfy! Book good!!” exclaimed self (who can often be terse).
A swift kick in the mental pants ended the discussion, and here we are.
And now, here we go.