Poll - start of the modern era
What do you think is the start of the "modern era"? You can define "modern era" however you like, but be reasonable (i.e., walking erect doesn't count). The start can be an invention, a discovery, a process, the formation of something, etc., but it can't be a natural event. I have one that will probably surprise people (both what it is and that it's mine), but list yours' first.