Some of it's not how much it matters in modern times but that without that decline in cost it wouldn't BE modern times. Even now there are large chunks of the w

Some of it's not how much it matters in modern times but that without that decline in cost it wouldn't BE modern times. Even now there are large chunks of the world where LEDs are making a huge difference because their lower cost means it's possible to power them with self-contained solar cells where it'd be a challenge to power even an incandescent nightlight without expensive fuel or a generator. For those who like podcasts, Planet Money also covered this a few years ago: http://www.npr.org/sections/money/2014/04/25/306862378/episode-534-the-history-of-light http://www.npr.org/sections/money/2014/04/25/306862378/episo...