In our shiny new technological age, it's easy to take a dim view of the past. We tend to imagine that people back then lived in a simpler age, full of candles, books and superstition but, actually, a lot of technology from those supposed dark ages used some pretty advanced scientific principles, many of which we're still trying to figure out to this day!
Sure, we might have iPhones, microwaves and the polio vaccine these day, but people from "back then" were living in a world with seismographs, nanotechnology and even robots (no, really). There are even cases of ancient technology being found to be as good or even superior to our modern equivalents.
Perhaps if they were alive today, they'd be the ones laughing at us.
Sure, they maybe didn't fully understand all the principles behind some of their most impressive tech, but the olde worlde folk deserve a lot more credit than we give them. And, no, it wasn't aliens.