Little things and ancient history

You know when you're in an elevator and you've gone up lots of floors in a single go, and the elevator decelerates as you approach your floor, and for a few seconds you feel lighter? I love that feeling. It's like you've finally figured out how to fly, and you're about to take off.

Unrelatedly, a question for the floor: I was reading this article about an ancient Greek analogue computer. The damn thing was thousands of years in advance of the previous earliest known analogue computer of equivalent complexity, which depending how you define these things was either in the 1640s by Pascal or not until Babbage's difference engine in 1822. Of course, there were earlier clockwork devices for predicting planets, notably the Chinese had one in 1000BC. So it wasn't, like, unprecedented. But still pretty amazing.

But the difference between the Chinese and Greek civilizations is that the Chinese one is still there, but the Acropolis is in ruins. So what happened to the ancient Greeks? Did their civilization collapse? Was there a famine? Why don't they rule Europe in science and technology now? Enlighten me about European history, folks.