Researchers typically compare algorithms by studying how they fare in worst-case scenarios. Imagine the world’s most confusing street grid, then add some especially perplexing traffic patterns. If you insist on finding the fastest routes in these extreme circumstances, the 1984 version of Dijkstra’s algorithm is provably unbeatable.
But hopefully, your city doesn’t have the world’s worst street grid. And so you may ask: Is there an algorithm that’s unbeatable on every road network? The first step to answering this question is to make the conservative assumption that each network has worst-case traffic patterns. Then you want your algorithm to find the fastest paths through any possible graph layout, assuming the worst possible weights. Researchers call this condition “universal optimality.” If you had a universally optimal algorithm for the simpler problem of just getting from one point on a graph to another, it could help you beat rush hour traffic in every city in the world.
Why aren’t ghosts naked? This was a key philosophical question for Cruikshank and many others in Victorian Britain. Indeed, stories of naked or clothesless ghosts, especially outside folklore, are exceedingly rare. Sceptics and ghost-seers alike have delighted in thinking about how exactly ghosts could have form and force in the material world. Just what kind of stuff could they be made of that allows them to share our plane of existence, in all its mundanity?
Having The Empusium embody, on a structural level, this idea of reality as “blurred, out of focus, flickering, now like this, now like that” is a brave and interesting move. Speaking of Görbersdorf, Thilo tells Mieczysław that “one sinks into a strange state of mind here”. The same could be said of Tokarczuk’s novel, but as invitation rather than warning.
The best speculative fiction gives us the distance to see our own world more clearly. Take Scott Guild’s debut novel Plastic. Most of its characters are just that, figurines, although others are waffles, or robots, or hairy shipping boxes with whirring propellers as means of locomotion. But their post-nuclear-war world is a nightmare of rampant consumerism, life lived virtually, and the ever-present anxiety over random terror attacks from groups trying to wake up the drugged-to-complacency citizenry to its own environmental destruction, in the book called the Heat Leap. It doesn’t take much for our humanity to be stirred by these unusual characters’ plights.