The novel “The Eternal Flame” by Greg Egan was published for the first time in 2012. It’s the second book in the Orthogonal trilogy and is the sequel to “The Clockwork Rocket“.

The generational starship Peerless is traveling in space in search of a technology that can save its crew’s homeworld. The advantage is that the time on the starship flows much slowly than on the planet. The problem is that it doesn’t carry enough fuel for the return trip and to make things worse there’s the problem of the limits of the resources for the crew survival.

While the scientists within the crew are looking for the solutions to their problems, the astronomer Tamara discovers an object in space. An expedition could find new fuel but involves several risks. Meanwhile, new biological studies risk creating a rift in the small society that lives on the Peerless.

“The Eternal Flame” is set several years after “The Clockwork Rocket” so the characters are completely different and is set in space, mainly on the starship Peerless, instead of a planet. The consequence is that the story is independent from the first novel but skipping it means losing all the bases of the Orthogonal trilogy.

This is especially harmful because it’s set in another universe with different physical laws. In “The Clockwork Rocket”, Greg Egan started illustrating those laws through the scientific discoveries of various characters. The author has put online a page of his website that explains the physics of that universe but it’s not like reading a novel.

Another problem is that the characters belong to a species with anatomy and physiology completely different from humans’. Again, in “The Clockwork Rocket” the reader slowly discovers the characteristics of this species, fundamental influences to their society and therefore also in the development of the story in “The Eternal Flame”.

This second novel in the Orthogonal trilogy directly continues the story begun in “The Clockwork Rocket” although it leaps forward in time. Greg Egan is one of the most important hard science fiction writers and the Orthogonal trilogy is in many ways an exploration of that universe.

Honestly sometimes you may be the impression that the story proceeds precisely in order to explain in detail the physics of the Orthogonal universe. As in “The Clockwork Rocket”, Greg Egan uses several graphics to accompany the characters’ discoveries and their theories. Therefore you need to have a certain level of knowledge of physics and mathematics to avoid getting lost but with this author that’s normal.

The story is, however, much more than the the physics of the Orthogonal universe. The social problems of the planet were important in the first book, so are those on the starship Peerless in the second book. The resources are limited and scientific research are also used to find new ways to support the crew during the long journey.

Among the many problems of the small society existing on the Peerless, Greg Egan focuses on women’s rights. Their species reproduces through fission so a woman dies when her children are born. For this reason, it’s men who take care of children and it’s them who have the equivalent of the human maternal instinct.

In their traditional society, women are considered incapable of taking care of a child, of course someone else’s, because according to the stereotype they lack the instincts they need. On the Peerless the needs and the presence of progressive people have started to make changes to their society and yet there are still many people linked to traditional values.

New discoveries in biology also lead to clashes between progressives, who accept gender equality, and traditionalists, who want to keep on controlling women especially in their reproduction. As in the first book, in “The Eternal Flame” Greg Egan is inspired by the human social problems to tell the story of a very different species.

Just as on Earth, on the Peerless there are people who reject the social implications of new scientific discoveries but are ready to take advantage of their practical benefits. Also from the emotional point of view, despite the profound differences this species feels the same emotions as humans and this greatly helps to understand the characters actions.

Because of its features, “The Eternal Flame” has often a slow pace, with many conversations among the characters and their discussions that often concern scientific theories. Instead , in other parts of the novel there’s action at a much faster pace. There are many characters so only a few are well developed but I think Greg Egan did overall a good job.

In my opinion, “The Eternal Flame” is a very good novel that continues at a high level the Orthogonal trilogy. If you liked the first book I strongly recommend to get this one as well.