I was a math major, for what it’s worth, and this still made my head hurt. Egan opens with an experiment gone wrong, a new, more stable configuration of vacuum starts expanding at half the speed of light, consuming the old universe as it goes, and the plot spins outward from there into a fight over whether to reverse it or study it.

What impresses me isn’t the scale of the disaster, it’s how seriously Egan treats the physics as physics, not metaphor. I don’t have the background to verify every equation-adjacent passage and I’m not going to pretend otherwise, but the internal consistency is obvious even from outside it, the way a novel about sailing can feel authentic to a non-sailor because the author clearly knows exactly how a boat behaves. A degree in physics would help you enjoy this wholly. I got maybe seventy percent of it and still found it worth the effort.

Where this differs from Diaspora, which I’d read first, is tone. This one’s more clinical, more focused on the vacuum-collapse problem as an intellectual puzzle than on identity and consciousness, though those themes are still present in the background, uploaded immortal humans wandering the stars as a fact of life rather than a plot point. The ending resolves a bit too conveniently for how hard everything before it fought for rigor, which is my one real complaint.

I ran hot and cold on this exactly the way I’ve heard other Egan readers describe him generally, when he’s good he’s genuinely great and when he’s not he’s a chore, and Schild’s Ladder sits mostly in the great category for me with a few chore-ish stretches in the middle third where the exposition outpaces the plot.

Four stars. Diaspora is the easier entry point if you’re new to Egan. This one takes the physics further and asks more patience of you, but it delivers a genuinely alien vision that stuck with me for weeks after finishing.