Whenever there are lists of the greatest and most profound inventions of all time, we almost always hear, among other things, about air conditioning, the internal combustion engine and electric light.  This last one, electric light, has seen to it that vast tracts of human population have never had to experience anything like total darkness.  What impact has that had.  As technology moves so much more rapidly than evolutionary biology, how has that impacted our species.  We’ve all seen the aerial views of the world at at night.  Vast population centers stretching for hundreds of miles, all brightly lit.  At the same time,  our migration to cities continues to create a nighttime culture that is very different than what our ancestors experienced.That's the world that Paul Bogard takes us to in The End of Night: Searching for Natural Darkness in an Age of Artificial Light.My conversation with Paul Bogard: