Even so, the generation of new useful knowledge is very far from routine, uniform, steady or continuous. Although the human race as a whole has experienced incessant change, individual peoples saw a much more intermittent flickering progress because the pace and place of that change was itself always changing. Innovation is like a bush fire that burns brightly for a short time, then dies down before flaring up somewhere else. At 50,000 years ago, the hottest hot-spot was west Asia (ovens, bows-and-arrows), at 10,000 the Fertile Crescent (farming, pottery), at 5,000 Mesopotamia (metal, cities),
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