> The closest I can think of in more recent times is the invention of the blue LED, which, it was obvious would open floodgates to 10x more efficient lighting.

> The closest I can think of in more recent times is the invention of the blue LED, which, it was obvious would open floodgates to 10x more efficient lighting. Not wrong, and I wouldn't want to 'regress', but compared that to going from using gas lighting and candles to the incandescent light, the introduction of LED lighting isn't as much of a step change. Also remember that there was a noticeable improvement in efficiency with fluorescent lamps pre-1970s: * https://en.wikipedia.org/wiki/Fluorescent_lamp https://en.wikipedia.org/wiki/Fluorescent_lamp