Scattering planets like billiards

kw: book reviews, science fiction, science fantasy, space fantasy, space aliens, interstellar politics

The book is billed as "The explosive finale to the 'Ringworld' and the 'Fleet of Worlds' series": Fate of Worlds by Larry Niven and Edward M. Lerner. This is the latest, and allegedly the last, of twelve books in these two intertwined "Known Worlds" series, half of them published by Tor Books.

Exploding planets and vanishing stellar systems are "explosive" enough. So far Niven has not introduced an exploding galaxy. Such events take far too long for a human-scale story, anyway. Even when "human scale" has been expanded in the "Known Worlds" books to a few hundred years beyond the traditional three score and ten. Niven didn't invent "boosterspice" but he makes great use of it.

The whole series encompasses events between 630 and 880 years in the future, more or less depending on relativistic effects, such as for the fleeing Fleet of Worlds, six planets driven toward galactic north at 0.8c, for which Tw = 0.6To (calendar coordination is hard enough when your year is as long as mine!).

Where a typical novel has 3-5 important characters, this one has 25 or more (depending on how many downloads of Jeeves you count), 21 of them "natural" individuals, the rest being AI's. The core characters are Nessus, of a vaguely equine alien species called Puppeteers, and the humans Louis Wu and Sigmund Ausfaller.

The Ringworld is Niven's most famous idea, a detailed construct probably inspired by the notion of a Dyson Sphere. Ringworld circles its primary star at a distance of about 100 million miles, or 160 million km, filling the orbit. Its length is thus more than 600 million miles or 1000 million km; its width is a million miles or 1.6 mkm. Its mass is similar to that of Jupiter, or more than 800 times Earth's mass. In one of the novels it is shown that such a ring's orbit is unstable, so it has engines along its rim (with its multi-mile-high walls to hold an atmosphere) that periodically correct the orbit. It is home to tens of trillions of "sentients" who belong to an unknown number of nonhuman species, most of whom know nothing of any of the others. There is a lot of room in 1.6 quadrillion square km, even when a substantial percent is shallow oceans: Earth's area is 510 million sq km, counting oceans. Inward from the ring is a smaller, segmented one, that revolves on a different schedule, producing days and nights on the Ring. This one is also driven as needed.

Among a ton of interesting ideas, one that seems unique to Niven is the Protector: A post-sexual development of a sentient species, when fed an appropriate diet, a protector is hyper-intelligent and pathologically paranoid. A protector's mission is preservation of the species from all imaginable dangers, and they have incredible imaginations. As gadgeteers, they are super-Tom Swifts, super-Edisons.

Another is the Gw'oth, starfishlike aliens that can link nervous systems via sockets in the ends of their five "arms" (tubercles in the story), to meld into group minds. A 16-fold meld in a hypercubical configuration is formidable indeed. One such group mind is found to be the power behind the "power behind the throne" of the Puppeteer planets.

The book weaves together numerous strands left hanging by all those that came before, returning not only Wu, Ausfaller and Nessus, but a number of other protagonists to a place of stability, if not honor. Considering that they all have used variously dishonorable means to accomplish their prior feats, that is no mean bit of writing! The drama begins when Ringworld vanishes, leaving a hyperspace- and gravitational ripple which rocks detectors for a considerable distance. It ends when a few planets also either explode or take flight; it seems someone has cracked a conundrum of hyperphysics relating to the behavior of a "spacecraft" deep in a gravitational well. There is a little fodder here for Niven and Lerner to continue the series should they so desire. I wouldn't mind.