It all began with nano-machines. The military developed a network of sand, machines the size of a grain of sand, that had sensors and the ability to connect and communicate?? through a "mesh" network. Each grain of sand could "see" the little space around it, send its observations to another grain of sand, passing it through the network of sand, until it reached the mother-ship computer. There, the tens of thousands of pieces of information were pieced together into a picture that could be understood and used by a human. All someone had to do was throw a handful of sand into a room and a three-dimensional video and sound replica of the room could be created, real time, by an observer anywhere on the internet.
The sand particles got smaller and smaller, until they could become an
aerosol, sprayed into a room, like a deodorizer. The mesh network of
little observers now floated in the air. It didn't take long for medical
researchers to start asking patients to inhale the tiny bots. And the
world of the body opened into real-time observations of blood flows and
Smaller still, and the tiny observers made it into the brain, into every
neuron, observing and reporting on every connection and interaction.
Soon enough, a model of the mind was populated with this matrix of
observations, and people's minds were able to move to digital replicas.