[dataweaver]

A framework for a sci-fi setting: the Core and Frontier. This setting sets up two drastically different societies side by side: a Radical Hard TL11 or 12 Core of high-population worlds networked together using mostly Hard SF wormholes; and a comparatively lightly populated TL6–9 Retrotech or Safe-Tech+Emergent Superscience Frontier.

The way it works is that the Superscience element of wormholes (specifically, whatever it is that lets you generate the negative energy densities needed to stabilize a wormhole's opening) is disruptive to all other forms of Superscience; and when the wormhole is big enough to send anything of a reasonable size through (e.g., people or spacecraft), the radius of the disruptive effect is large enough to blanket an entire star system. So the Core worlds have to do without Superscience other than the wormholes. That said, having several massive population centers and industrial bases linked together by wormholes helps amplify the progression of those technologies that can still work, leading to the Core having a rather high Hard SF technology base.

By contrast, the breakthroughs needed for the rest of the Superscience stuff turn out to be remarkably simple in hindsight: it can be built and maintained by as low as a TL6 technology base. And for historical and cultural reasons, the Frontier is mostly populated by the sorts of people who would prefer Safe-Tech restrictions: the earliest pioneers were fleeing the transhuman and posthuman aspects of Core culture.

The Core and Frontier are mostly kept isolated from each other: on the one hand, Frontier starships tend to have Warp drives for FTL and Reactionless Drives for STL, both of which fail if they stray too close to a Core world. On the other hand, wormholes need to be created and stabilized in close proximity to reach other; and even a “pinpoint wormhole” has a large enough disruptive effect that you can't transport it on board a Frontier ship: you have to send it out on a Hard SF slower-than-light space probe, which takes years or decades and small fortunes to do.

And even the pinpoint ones produce enough of a signature that any Frontier world worth its salt will see it coming and have a chance at destroying it before it gets anywhere near them. As such, wormhole links only get established to Frontier worlds if the Frontier world permits it.

For the most part, trade between the Core and Frontier requires a Warp-capable ship with some sort of Hard SF STL Drive: the ship can then fly as close to a Core world's system as possible using its FTL drive, and then switch to the “rocket engines” to complete the journey. So the barrier between the two isn't insurmountable; but it's enough to provide a semi-plausible explanation why the Core culture and technologies don't spread out into the Frontier.