You can look at the timeline charts in the back of your textbook to see when things were invented in different cultures at about the same time to see what I'm talking about.

Using time charts — All these metrics can be plotted against time to chart trends. For instance, a trend showing a steady increase in effort to fix defects should be vigorously investigated.

I found a good book that thoroughtly analyzed the relevant time period and amplified its analysis with charts and illustrations.