In the seminal piece of literary sci-fi that is Snow Crash, the author Neal Stephenson imagines a metaverse — a virtual reality world into which the technologists of a collapsed, balkanized America project their avatars.

At the genesis of Stephenson’s virtual reality world (explained briefly in the book), the avatars started off as low-fidelity versions of the people behind them. But as the technology progressed, they became more and more representative and life-like, until the avatars reached the point that they were essentially digital replicas of their owners, projected into the cyber realm.

In Neal Stephenson’s near-futuristic America, this metaverse was made possible by some wearable technology and a virtual reality headset.

The piece he missed was Facebook.