I don't remember their initial post about the lava lamps, but I had assumed that was a marketing gimmick more than anything... a neat visual way to convey what entropy is in a way normal humans can comprehend.
It's certainly not a scalable solution for entropy, and there are so many ways for it to fail as a sole source, as well.
It's certainly not a scalable solution for entropy, and there are so many ways for it to fail as a sole source, as well.