Recently I posed this far-out scenario  as a means of stimulating careful thought about economic progress and the way that progress is measured using conventional concepts and national-income-accounting categories.
Turns out that my scenario isn’t as far-fetched as I assumed . (HT to the more-than-a-dozen people who’ve sent me links to this video) Wow. Wow! Wow ten-thousand times over!
Watching this remarkable technology, I can’t help but reflect on the importance of Matt Ridley’s point that progress is fueled by ideas having sex with each other ; the resulting creativity makes optimism rational.