The last thing we do is connect the two ends of the billion-mile-long O’Neill cylinder, so that now you have a loop. Or, as in Heaven’s River, a billion miles.

After all, for any given diameter, a length of ten miles isn’t any more of an engineering challenge that one mile. Think of a topopolis as an O’Neill cylinder stretched to a ridiculous length. But with a single cylinder, you can enter and exit through the ends, preferably along the axis where there’s no pseudo-gravity. In order to keep the outer shell and the inner cylinder from touching, we place magnetic bearings in the gap. We make it non-rotating and separate from the cylinder so that it doesn’t place a load on the cylinder. So stick a non-rotating shell around the cylinder, made of rock or other friable material, to absorb meteor impacts. And like Johanssen said in The Martian, we need air to not die. One good meteor punch and all the air drains out of the cylinder. That’s great, but possibly a little exposed. There are different designs for introducing light into the cylinder, but the one used in Heaven’s River is a fusion-powered light source on a structure that runs down the center of the cylinder. An O’Neill cylinder, at its most basic, is just a large drum, rotating around its axis to create centrifugal pseudo-gravity on the inside surface. I’ve seen a few comments that Heaven’s River is not sufficiently well described in the book, so I’ve put together this post to describe it in more detail.įirst, let’s start with an O’Neill cylinder, something most people are far more familiar with. Instead he's become a sky god to a primitive native species, the only hope for getting humanity to a new home, and possibly the only thing that can prevent every living thing in the local sphere from ending up as dinner.If you haven’t read the book yet, best stop now. A system-wide war has killed off 99.9% of the human race nuclear winter is slowly making the Earth uninhabitable a radical group wants to finish the job on the remnants of humanity the Brazilian space probes are still out there, still trying to blow up the competition And the Bobs have discovered a spacefaring species that sees all other life as food.īob left Earth anticipating a life of exploration and blissful solitude. But that's the only part of the plan that's still in one piece. To add to the surprise, he is now a sentient computer and the controlling intelligence for a Von Neumann probe.īob and his copies have been spreading out from Earth for 40 years now, looking for habitable planets. Look for The Bobiverse Signed Limited Edition] on Amazonīob Johansson didn't believe in an afterlife, so waking up after being killed in a car accident was a shock. Bobiverse fans: a signed limited edition of all three books in a boxed set, signed by the author, is now available on Amazon.

Bobiverse series