QM in SF

Although writers of science fiction can be reasonably accused of flouting the laws of physics, they nevertheless incorporate real physics—or extrapolations of real physics—in their work.

Quantum mechanics especially tempts writers. Despite being more than a century old, the theory seems perpetually modern, like Bauhaus architecture, twelve-tone music, or imagist poetry. Moreover, quantum mechanics is difficult, subtle, and weird.

There is, however, a problem with incorporating entanglement, complementarity, and other quantum concepts into a novel: Quantum mechanics is most apparent and influential in systems that are small, cold, and isolated. Novelists tend to prefer their stages large, their action hot, and their characters interactive.

That mismatch is overcome in Ian McDonald’s 2007 novel Brasyl. Set in the Amazon jungle in 1732, Rio de Janeiro in 2006, and São Paulo in 2032, the novel hinges on Hugh Everett’s many-worlds interpretation of quantum mechanics.

Everett devised the interpretation in 1957 to circumvent the unpalatably probabilistic nature of the orthodox “Copenhagen” interpretation. According to Everett, observing a system doesn’t force it into one of its many possible states. Rather, observing a system forces it into all of its many possible states, creating for each of them a new and parallel universe.

Brasyl prominently features another manifestation of quantum mechanics: quantum computation, which by 2032 has become not only possible but also dangerous. (I won’t say why, lest I spoil the plot for you.)

I suspect McDonald found the many-worlds interpretation attractive because, unlike other quantum manifestations, it plays out in the macroworld, if only an imaginary one. Quantum computation, however, remains confined to small isolated systems. But to work, it must scale up—by 2032, if McDonald is correct.