Oh God have you seen that poster? it's like a scientific advancement axis against a time axis, and it show's humanities movements. Steadily going up from neolithic hunter-gatherer times, it gets all the way to the bronze age, then along comes the middle ages (lol Christianity in full swing and power), and then we just fall down and stay not moving for like five hundred years, and then we pick up at our current pace. The funny thing is, a line was traced at the gap left by the middle ages, with the commentary at the bottom: "Just think, we could have been exploring the galaxy by now."