The definition of hard sf is almost as slippery as that of science fiction in general, but few who’ve read any of his work would contend that Greg Egan is not an exemplary practitioner of the subgenre. His work in both the short and long forms is defined by plots grounded in cutting-edge research or speculation, be it in mathematics, physics, astronomy, neuroscience or some combination thereof. Oceanic collects a dozen short stories and novellas published within the last decade or so (including a couple first seen in the pages of this very organ) and showcases Egan’s ability to flick the sensawunda switch with an authority that few of his contemporaries can match.

Hard sf sometimes stands accused of being opaque to outsiders, emotionally cold or insufficiently concerned with character and story in deference to some Gernsbackian didactic impulse. While it would be impossible to claim Egan’s fiction isn’t highly dependent on science for its narrative thrust, Oceanic demonstrates clearly that he’s no emotionally ascetic brainiac; these stories burgeon with characters who, even when ensconced in a fully posthuman state of being, have authentically human hearts and minds. That their passions are frequently intertwined with science should be no surprise given Egan’s background in mathematics and computing.

Not all his characters are boffins, however, and the choice to open Oceanic with “Lost Continent”—a story that neatly reframes the refugee experience in temporal terms as well as geographical and cultural—is a wise one that immediately puts the lie to any accusation of a lack of compassion for the human condition. The story’s focal character is uprooted from a medieval Middle Eastern past and dispatched through a temporal vortex, ending up in what appears to be a contemporary version of Australia; his sense of alienation and his bafflement at the Byzantine and Heller-esque bureaucracy that now constrains his existence is sensitively handled, while suggesting that Egan is far from enamoured of his government’s handling of asylum seekers.

But make no mistake, Egan loves to write about science, and about those who toil in its temples. It would be fair to suggest that the degree of scientific detail in much of his work might render it unpalatable to those uninterested or inexperienced in the scientific idiom, but to dismiss his work on that basis seems no fairer than dismissing a politician for writing stories that revolve around politics. And I would contend that Egan’s aim is not to teach science to his readers; indeed, I think he simply assumes a reasonable level of scientific literacy in his readers, and doesn’t care to dumb down the stories that speak to his heart for the sake of a wider readership. If Egan is trying to teach anything, I suspect it is the joy of science he wishes to highlight. Oceanic abounds with characters whose greatest love is that of learning, of expanding the sphere of rational knowledge… and Egan strives to communicate that joy in terms that don’t require a doctorate to be understood.

Motives aside, Oceanic is an ideal collection for any reader craving the thrill of big ideas or cosmic scales of space and time: Egan waves away lightyears-long interstellar journeys in a sentence, bridges alternate realities with a few equations and installs believable characters in bodies or environments almost unimaginably distant from our meat-machine existences. He makes maths into sports, and portrays galaxy-wide civilisation as an inevitability while leaving plenty of unexplored spaces for his characters to quest into—be those spaces within their minds or without. What is most notable is how few physical conflicts between sentient beings there are in his work; for Egan, perhaps the only battle worth fighting is against our imperfect understanding of the universe. And looking at the world as we know it today, I think he has a good point.