> With people walking a few hours between villages, ideas could theoretically spread at >10 kilometers a day. You needed a lot more than a few hours to walk be

> With people walking a few hours between villages, ideas could theoretically spread at >10 kilometers a day. You needed a lot more than a few hours to walk between the villages in the Eurasian steppes, mostly because there were no villages there. Population density back then wasn't what it is now.