There is a wonderful book by Jared Diamond called "Guns, Germs and Steel" in which he discusses the question of the relative rates of technological development on different continents. To summarize it in a few sentences - agriculture developed earlier in Eurasia because the east-west axis of the land mass allowed crops native to one region to spread to others in similar climate zones. With an agricultural surplus, cities could develop and the specialization necessary to an advanced culture. Geographically Europe with its islands, peninsulas and mountain barriers became many states rather than a single empire like China and technology develops faster when different states are competing and a central authority is not in a position to block progress.
I'm not doing the book justice, so go read it.
