The digital network and the physical world are still sometimes talked about as if they were separate, parallel universes, or different “dimensions” of reality, in the popular or science-ﬁction sense of the term. But in recent years, the metaphors behind the term have been foregrounded, made obvious, because their premises have been everywhere disrupted. That way of thinking about the digital and the physical has begun to lose its transparency, as it were, so that, newly opaque and in front of us, the idea of the dimensional divide has been exposed. That explains, I think, the often-reported sense that a rift has opened between the supposedly separate worlds of the digital and the physical. Not that people consciously believe the divide is real, necessarily, but that the divide has in the past felt real, and that it feels now as if we’re living at the breach.