It is difficult to overestimate the impact that the invention of the light bulb had on knowledge and productivity. For instance, this invention enabled people to read at night, increasing literacy.
On the other hand, there are profound medical ramifications for forgoing daily periods of darkness. Sleep disorders, for instance, are now tied to every major disease. Working night shifts is now listed by the WHO as a probable carcinogen.
That is not to say that the invention of the light bulb was a bad thing for humanity. But it is certainly a mixed bag, and we need to better understand its disruptive impact on the human condition. That is the lesson of Paul Bogard's new book, The End of Night: Searching for Darkness in an Age of Artificial Light, is a discussion of life after the light bulb.