What do we mean by AI?
By the start of the 21st century it was clear that encoding a set of behavioral rules did not constitute intelligence. Despite the increasingly complex decision trees built into expert systems, and the variety of responses that could simulate human interaction, nothing even close to resembling a thinking machine was on the horizon; the claims of prominent researchers in the mid-20th century that the problem was substantially solved were proved optimistic.
It was not until the middle part of the 21st century that meaningful progress was made, enabled by the convergence of three critical disciplines.
The final scaling of planar semiconductor technology reached its zenith, culminating in trillion transistor chips with thousands of processor cores and gigabytes of on-board memory. Coupled with unprecedented data storage capacity, entire simulated 3D worlds were being created across the connected globe, building the fledgling infrastructure that would eventually provide a home to a new form of life: synthetic sentience.
At the same time, neuroscience research penetrated the behavioral relationships between individual neurons, collections of cooperating neural networks, and the emergent cognitive abilities that resulted. Although the picture was incomplete and fractured, the insights that were gained during this renaissance era cannot be understated.
Molecular self-assembly was the last piece of the puzzle to fall into place, arriving late on the scene, but becoming an enabling force as scientists and engineers from divergent disciplines experimented with the seemingly infinite possibilities the technology opened before them. Leaping from the broad platform that the microelectronics industry had created in nearly a century of progress, silicon-cell electronics became the scaffold of abstract thought that had eluded scientists for generations.
In hindsight, it seems almost inevitable that man-made life should emerge from this cauldron of ingenuity, but at the time it was anything but a foregone conclusion.
Personal notes, Henrietta Climbsworth, On the Construction of a new World Mind; Dublin, Ireland; August, 2201