Greg Egan is an Australian mathematician who has been writing hard science fiction for thirty years, although his hard science is the stuff that sits at the borderland of philosophy: the relationship between mathematics and reality, the nature of consciousness, the implications of quantum mechanics. Previous novels have involved speculations on what life might be like if quantum superpositions could involve entire people (like the cat in Schrödinger’s infamous thought experiment), and what it might be like to inhabit a universe with an extra spatial dimension.

Anyway, as you can see, Egan is so well established that his publisher has given him his own typeface, and his name printed bigger than the title.

When The Clockwork Rocket was published in 2011, it was a new departure for Egan, because it was billed as the first part of a trilogy—his previous novels have all stood alone. And, knowing how complicated his science fiction is, I had a horrible feeling I wouldn’t be able to properly remember the set-up from the first book by the time the second and third volumes were published. So I bought the book, and stock-piled it. I did the same for The Eternal Flame in 2012, and The Arrows Of Time in 2013.

Finally, I’ve got around to reading all three as if they were a single, 1,000-page novel—and I’m glad I waited.

What has preoccupied Egan in these novels is the geometry of spacetime. Although Einstein showed us that time is simply another dimension, he also showed that it’s a different kind of dimension—it’s treated differently mathematically, in a way that gives spacetime a hyperbolic geometry, which produces all the distortions of space and time experienced by observers in relative motion. Egan asked himself what a universe would be like if the time dimension was exactly like the space dimensions, producing a basic spacetime geometry that could be understood by Euclid. He did a lot of mathematics with this idea, working hard to come up with the physics for an internally consistent alternate universe, with that kind of spacetime, which could support intelligent life. A sample of his workings appear on his website.

Egan’s new universe is a strange place—one in which it’s possible to achieve infinite velocity with a finite amount of energy, in which the total energy of a moving object is less than that of a stationary one, in which it’s impossible to lose heat by thermal radiation, in which you can travel in time or convert yourself to antimatter simply by motoring around at a high velocity on a curved course. The physics of matter is different, too—liquids are horribly unstable, so biology has to be based on solids and gases. Egan comes up with flexible beings who continuously remodel their bodies using internal light signals. Into that mix, he stirs a unique method of reproduction—females, once “triggered” by a male, become dormant, adopt a smooth elliptical shape, and then split into between two and four children. The children are then cared for by the male.

So he’s given himself a ludicrously complicated set-up to impart in the form of a novel. No wonder he decided to build his alien society around recognizable human models (schools, factories, farms), and to give his aliens recognizable human emotions and concerns. At least there are some things we can take for granted as the story progresses.

He does marvellously well in drip-feeding the strange biology (and its associated gender politics) into the story without subjecting the reader to huge data-dumps. For the physics … well, the story is about the physics, to a large extent. In the three novels we follow three separate generations of scientists as they piece together the detail of how their universe works.

In The Clockwork Rocket, the simple geometry of the universe allows scientists to come to an understanding of spacetime while at a technological level similar to our Enlightenment—as if Newton discovered Relativity. The odd energetics means that they can also access the equivalent of nuclear energy via simple chemistry. The “clockwork rocket” of the title is a multigeneration interstellar spacecraft, an entire mountain launched into space with “chemical” rockets, stabilized and maintained by simple clockwork mechanisms.

In The Eternal Flame, the inhabitants of the interstellar ship develop their equivalent of quantum mechanics and laser technology. Egan’s scientists do a lot of talking and draw a lot of diagrams, and I found this a little more wearing than I did in the previous novel. Multiple pages detailing the discovery of quaternions was too much even for me, and I like quaternions. This was offset by a separate story strand about the aliens’ problematic reproductive biology, in which females die while producing children. Scientists attempting to find ways for females to avoid or survive childbirth are subjected to harassment that has clear parallels in our own world.

In The Arrows Of Time, Egan shows how his universe allows the inhabitants to reverse the direction of flow of their own time, relative to other objects. It’s possible to receive messages from your own future—what might the implications of that be? It’s also possible to bring big, complicated objects together which have their entropy running in opposite temporal directions—what happens if you land on a planet that is ageing in reverse?

So:
Lots of big fun physics, for people who like big fun physics. But many little personal stories of conflict, failure, success and deeply strange love. There are characters in jeopardy, puzzles to be solved, daring rescues and civil insurrections. But if you don’t like big fun physics, I suspect the background to this series might be too weirdly complicated to let you just wing the science and enjoy the story.

Note: I’ve now review Egan’s subsequent big fun physics novel, Dichronauts. You can find that review here.