Six Good Reasons Why the Pak Didn't build the Ringworld

This post is commentary on an issue in the expansive science fiction universe created by Larry Niven. Larry wrote dozens of short stories and novels over many decades all set in Known Space, a science fiction ‘future history’ which included a fictive past history of our galaxy as well. His stories and the development of Known Space were hugely influential on other science fiction authors and his ideas pop up all over the place even today. The authors behind The Expanse TV show and book series cite Larry as a major influence, for example.

This article examines the origins of the Ringworld, a vast and ancient megastructure explored by the characters in several of Larry’s novels. It originated as a post to the Larry Niven mailing list many years ago.

In particular theory popular among fans of the books and raised by characters in the novels, that the ring was constructed by a species called the Pak. I’m not having it, and here’s why.

The Argument For

The theory that the Pak built the ring goes something like this. Pak Protectors are incredibly intelligent and industrious. They have very advanced technology and are capable of large scale engineering projects, especially when large numbers collaborate. The latter requirement, large scale collaboration, is tricky because generally speaking protectors only care about their own bloodline descendents. However sometimes, when a protector’s bloodline is wiped out, they manage to adopt the whole species as their bloodline. Such protectors are known to have worked together for the long term benefit and survival of the Pak as a whole.

So the idea is that a gang of childless Pak protectors built the Ringworld as a giant home for their’ species’ unintelligent breeder stage, literally a vast breeding ground, left the whole thing on automatic then went away. They did this in the galactic vicinity of Earth because Pak had visited Earth before, so they came here first then set up shop not too near but not too far away to build the Ring. Certainly the ring is populated by the evolved descendents of Pak breeders.

The Argument Against

If Pak protectors had visited Earth, they would know that Pak breeders left on their own will tend to evolve away from Pak normal form. Since the Ring contains maps of several other worlds near Earth, populated with sentient aliens, the Protectors must have visited those worlds too.

What do we know about Pak protectors? They are fiendishly intelligent, rabidly xenophobic and obsessed with the genetic purity of their species.

1. The idea that Pak protectors would suddenly decide that their non-sentient, essentially helpless breeder stage is better off without protectors to look after them is ludicrous. They'd also know that the breeders would mutate from studying the Earth breeder colony. Letting that happen is simply unthinkable to a Pak protector.
2. The Protectors would have known about the Kzin, Grogs, Humans, Martians, etc. and rather than wipe them out, as Brennan-monster and Phssthpok wiped out the Martians on Mars, they brought them to the ring and gave them a nice cozy home to live in, right next door to the breeders, and within spitting distance (in ring terms) of the command centre for the entire ring under the map of Mars. Yeah, right, good move!
3. The theory presupposes that the Ringworld engineer protectors found the records of the failed Earth colony and followed its path in secret. If it was a secret, why did they leave records of the Earth expedition in the great Library on Pakhome for Phssthpok to find? Suppose a protector decided to go on some fool errand to rescue the Earth breeders with a load of thallium oxide, or suppose a Pak family decided to conquer Earth for itself? The ring would have a planet full of protectors from Earth right on it’s doorstep!
4. Pak protector technology doesn't use automated control systems. Phssthpok flew all the way from the galactic core on manual, without so much as a rudimentary autopilot. They just don't trust automatics, yet the ring is completely automated, from the flup dredges and recycling system, to the attitude control jets and the meteor defense laser.
5. Why only build one ringworld. When you finish one, why not just build another, and another, and another. You've got something better to do? Suppose there are other ringworlds out there, would they let this one alone, knowing it's packed with a trillion potential protectors of radically different bloodlines?
6. Who keeps killing off the protectors that sporadically get created on the ring? Somebody must be doing it. Why are there any attitude control jets still in place? If I were a new protector on the ring, the first thing I'd do it put a bunch of juvenile breeders of my species on an attitude control jet ramship, with one adult and a time released store of tree-of-life. Launch the ramship and let the timer release the tree-of-life and turn the adult into a protector. When it wakes up it’s already on a fast trajectory away from the ring. It’s mission is to establish the species on new worlds away from the ring, helping guarantee the long term survival of the species whatever happens on the ring. It's simply the optimum survival strategy.

So I really don’t buy the idea that protectors of any sub-species designed and built the Ring. It doesn’t work like any known Pak technology, requires that they behaved in radically un-Pak like ways and took risks that would appall any right-thinking protector. It also requires that they assume that other Pak protectors would also behave in extremely non-Pak like ways. I’m just not buying it.