Greg Egan is one of those authors who is little known outside his genre (hard sci-fi) and perhaps inscrutable to lay readers, but unforgettable for true fans. Oceanic is a compelling collection that fully justifies Egan’s reputation as the “hardest” hard sci-fi author. Rather than simply stating that “an interstellar probe was sent”, Egan dives into the plausible-yet-fictional physics behind the probe, often in excessive detail.

In another Egan anthology, Axiomatic, the core themes are mind-body dualism and simulated consciousness. Oceanic relegates these concepts to the background – as if digital copies of consciousness are already commonplace – allowing Egan to focus more thematically on AI safety and space travel. It’s a well-constructed collection with a cohesive “cinematic universe,” though each story stands on its own. For example, the synthetic human Helen from Singleton reappears in Oracle, explaining how humanity ends up in synthetic bodies. Induction chronicles Earth’s galactic expansion through “spores” that land in new solar systems and use nanomachines to build infrastructure, ready to receive beamed consciousnesses and load them into new bodies. The story’s title hints at Egan’s suggestion that once this is achieved for one planet, it will soon spread across the galaxy by induction. This groundwork builds toward Riding the Crocodile, Glory, and Hot Rock, which feature a post-scarcity galactic society called the Amalgam. Here, inhabitants can choose to live as digital consciousnesses or inhabit synthetic bodies, freely exploring worlds as they please.

Having said that, the best story in the collection is the standalone Dark Integers. This is Egan at his most creative. Mathematics itself obeys Einstein locality, allowing different parts of the universe to have different mathematical truth. Aliens are involved. It’s wacky, mind-bending, and Hofstadter-coded, and pushes the boundaries of conceptual sci-fi. The same can be said of Egan more generally. But it’s not for the faint of heart!

Synopses

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Spoilers!

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Highlights